first commit

Classes/AbstractDataHandlerListener.php

@@ -0,0 +1,217 @@
+<?php
+namespace WapplerSystems\Meilisearch;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2015-2016 Timo Schmidt <timo.schmidt@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Index\Queue\RecordMonitor\Helper\ConfigurationAwareRecordService;
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\Database\QueryGenerator;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Changes in TYPO3 have an impact on the solr content and are caught
+ * by the GarbageCollector and RecordMonitor. Both act as a TCE Main Hook.
+ *
+ * This base class is used to share functionality that are needed for both
+ * to perform the changes in the data handler on the solr index.
+ *
+ * @author Timo Schmidt <timo.schmidt@dkd.de>
+ */
+abstract class AbstractDataHandlerListener
+{
+    /**
+     * Reference to the configuration manager
+     *
+     * @var \WapplerSystems\Meilisearch\Domain\Index\Queue\RecordMonitor\Helper\ConfigurationAwareRecordService
+     */
+    protected $configurationAwareRecordService;
+
+    /**
+     * @var FrontendEnvironment
+     */
+    protected $frontendEnvironment = null;
+
+    /**
+     * AbstractDataHandlerListener constructor.
+     * @param ConfigurationAwareRecordService|null $recordService
+     */
+    public function __construct(ConfigurationAwareRecordService $recordService = null, FrontendEnvironment $frontendEnvironment = null)
+    {
+        $this->configurationAwareRecordService = $recordService ?? GeneralUtility::makeInstance(ConfigurationAwareRecordService::class);
+        $this->frontendEnvironment = $frontendEnvironment ?? GeneralUtility::makeInstance(FrontendEnvironment::class);
+    }
+
+    /**
+     * @return array
+     */
+    protected function getAllRelevantFieldsForCurrentState()
+    {
+        $allCurrentStateFieldnames = [];
+
+        foreach ($this->getUpdateSubPagesRecursiveTriggerConfiguration() as $triggerConfiguration) {
+            if (!isset($triggerConfiguration['currentState']) || !is_array($triggerConfiguration['currentState'])) {
+                // when no "currentState" configuration for the trigger exists we can skip it
+                continue;
+            }
+
+            // we collect the currentState fields to return a unique list of all fields
+            $allCurrentStateFieldnames = array_merge($allCurrentStateFieldnames, array_keys($triggerConfiguration['currentState']));
+        }
+
+        return array_unique($allCurrentStateFieldnames);
+    }
+
+    /**
+     * When the extend to subpages flag was set, we determine the affected subpages and return them.
+     *
+     * @param int $pageId
+     * @return array
+     */
+    protected function getSubPageIds($pageId)
+    {
+        /** @var $queryGenerator \TYPO3\CMS\Core\Database\QueryGenerator */
+        $queryGenerator = GeneralUtility::makeInstance(QueryGenerator::class);
+
+        // here we retrieve only the subpages of this page because the permission clause is not evaluated
+        // on the root node.
+        $permissionClause = ' 1 ' . BackendUtility::BEenableFields('pages');
+        $treePageIdList = $queryGenerator->getTreeList($pageId, 20, 0, $permissionClause);
+        $treePageIds = array_map('intval', explode(',', $treePageIdList));
+
+            // the first one can be ignored because this is the page itself
+        array_shift($treePageIds);
+
+        return $treePageIds;
+    }
+
+    /**
+     * Checks if a page update will trigger a recursive update of pages
+     *
+     * This can either be the case if some $changedFields are part of the RecursiveUpdateTriggerConfiguration or
+     * columns have explicitly been configured via plugin.tx_meilisearch.index.queue.recursiveUpdateFields
+     *
+     * @param int $pageId
+     * @param array $changedFields
+     * @return bool
+     */
+    protected function isRecursivePageUpdateRequired($pageId, $changedFields)
+    {
+        // First check RecursiveUpdateTriggerConfiguration
+        $isRecursiveUpdateRequired = $this->isRecursiveUpdateRequired($pageId, $changedFields);
+        // If RecursiveUpdateTriggerConfiguration is false => check if changeFields are part of recursiveUpdateFields
+        if ($isRecursiveUpdateRequired === false) {
+            $solrConfiguration = $this->frontendEnvironment->getSolrConfigurationFromPageId($pageId);
+            $indexQueueConfigurationName = $this->configurationAwareRecordService->getIndexingConfigurationName('pages', $pageId, $solrConfiguration);
+            if ($indexQueueConfigurationName === null) {
+                return false;
+            }
+            $updateFields = $solrConfiguration->getIndexQueueConfigurationRecursiveUpdateFields($indexQueueConfigurationName);
+
+            // Check if no additional fields have been defined and then skip recursive update
+            if (empty($updateFields)) {
+                return false;
+            }
+            // If the recursiveUpdateFields configuration is not part of the $changedFields skip recursive update
+            if (!array_intersect_key($changedFields, $updateFields)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * @param int $pageId
+     * @param array $changedFields
+     * @return bool
+     */
+    protected function isRecursiveUpdateRequired($pageId, $changedFields)
+    {
+        $fieldsForCurrentState = $this->getAllRelevantFieldsForCurrentState();
+        $fieldListToRetrieve = implode(',', $fieldsForCurrentState);
+        $page = BackendUtility::getRecord('pages', $pageId, $fieldListToRetrieve, '', false);
+        foreach ($this->getUpdateSubPagesRecursiveTriggerConfiguration() as $triggerConfiguration) {
+            $allCurrentStateFieldsMatch = $this->getAllCurrentStateFieldsMatch($triggerConfiguration, $page);
+            $allChangeSetValuesMatch = $this->getAllChangeSetValuesMatch($triggerConfiguration, $changedFields);
+
+            $aMatchingTriggerHasBeenFound = $allCurrentStateFieldsMatch && $allChangeSetValuesMatch;
+            if ($aMatchingTriggerHasBeenFound) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * @param array $triggerConfiguration
+     * @param array $pageRecord
+     * @return bool
+     */
+    protected function getAllCurrentStateFieldsMatch($triggerConfiguration, $pageRecord)
+    {
+        $triggerConfigurationHasNoCurrentStateConfiguration = !array_key_exists('currentState', $triggerConfiguration);
+        if ($triggerConfigurationHasNoCurrentStateConfiguration) {
+            return true;
+        }
+        $diff = array_diff_assoc($triggerConfiguration['currentState'], $pageRecord);
+        return empty($diff);
+    }
+
+    /**
+     * @param array $triggerConfiguration
+     * @param array $changedFields
+     * @return bool
+     */
+    protected function getAllChangeSetValuesMatch($triggerConfiguration, $changedFields)
+    {
+        $triggerConfigurationHasNoChangeSetStateConfiguration = !array_key_exists('changeSet', $triggerConfiguration);
+        if ($triggerConfigurationHasNoChangeSetStateConfiguration) {
+            return true;
+        }
+
+        $diff = array_diff_assoc($triggerConfiguration['changeSet'], $changedFields);
+        return empty($diff);
+    }
+
+    /**
+     * The implementation of this method need to retrieve a configuration to determine which record data
+     * and change combination required a recursive change.
+     *
+     * The structure needs to be:
+     *
+     * [
+     *      [
+     *           'currentState' => ['fieldName1' => 'value1'],
+     *           'changeSet' => ['fieldName1' => 'value1']
+     *      ]
+     * ]
+     *
+     * When the all values of the currentState AND all values of the changeSet match, a recursive update
+     * will be triggered.
+     *
+     * @return array
+     */
+    abstract protected function getUpdateSubPagesRecursiveTriggerConfiguration();
+}

Classes/Access/Rootline.php

@@ -0,0 +1,228 @@
+<?php
+namespace WapplerSystems\Meilisearch\Access;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Core\Utility\RootlineUtility;
+use TYPO3\CMS\Frontend\Page\PageRepository;
+
+/**
+ * "Access Rootline", represents all pages and specifically those setting
+ * frontend user group access restrictions in a page's rootline.
+ *
+ * The access rootline only contains pages which set frontend user access
+ * restrictions and extend them to sub-pages. The format is as follows:
+ *
+ * pageId1:group1,group2/pageId2:group3/c:group1,group4,groupN
+ *
+ * The single elements of the access rootline are separated by a slash
+ * character. All but the last elements represent pages, the last element
+ * defines the access restrictions applied to the page's content elements
+ * and records shown on the page.
+ * Each page element is composed by the page ID of the page setting frontend
+ * user access restrictions, a colon, and a comma separated list of frontend
+ * user group IDs restricting access to the page.
+ * The content access element does not have a page ID, instead it replaces
+ * the ID by a lower case C.
+ *
+ * The groups for page elements are compared using OR, so the user needs to be
+ * a member of only one of the groups listed for a page. The elements are
+ * checked combined using AND, so the user must be member of at least one
+ * group in each page element. However, the groups in the content access
+ * element are checked using AND. So the user must be member of all the groups
+ * listed in the content access element to see the document.
+ *
+ * An access rootline for a generic record could instead be short like this:
+ *
+ * r:group1,group2,groupN
+ *
+ * In this case the lower case R tells us that we're dealing with a record
+ * like tt_news or the like. For records the groups are checked using OR
+ * instead of using AND as it would be the case with content elements.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class Rootline
+{
+
+    /**
+     * Delimiter for page and content access right elements in the rootline.
+     *
+     * @var string
+     */
+    const ELEMENT_DELIMITER = '/';
+
+    /**
+     * Storage for access rootline elements
+     *
+     * @var array
+     */
+    protected $rootlineElements = [];
+
+    /**
+     * Constructor, turns a string representation of an access rootline into an
+     * object representation.
+     *
+     * @param string $accessRootline Access Rootline String representation.
+     */
+    public function __construct($accessRootline = null)
+    {
+        if (!is_null($accessRootline)) {
+            $rawRootlineElements = explode(self::ELEMENT_DELIMITER, $accessRootline);
+            foreach ($rawRootlineElements as $rawRootlineElement) {
+                try {
+                    $this->push(GeneralUtility::makeInstance(RootlineElement::class, /** @scrutinizer ignore-type */ $rawRootlineElement));
+                } catch (RootlineElementFormatException $e) {
+                    // just ignore the faulty element for now, might log this later
+                }
+            }
+        }
+    }
+
+    /**
+     * Adds an Access Rootline Element to the end of the rootline.
+     *
+     * @param RootlineElement $rootlineElement Element to add.
+     */
+    public function push(RootlineElement $rootlineElement)
+    {
+        $lastElementIndex = max(0, (count($this->rootlineElements) - 1));
+
+        if (!empty($this->rootlineElements[$lastElementIndex])) {
+            if ($this->rootlineElements[$lastElementIndex]->getType() == RootlineElement::ELEMENT_TYPE_CONTENT) {
+                throw new RootlineElementFormatException(
+                    'Can not add an element to an Access Rootline whose\' last element is a content type element.',
+                    1294422132
+                );
+            }
+
+            if ($this->rootlineElements[$lastElementIndex]->getType() == RootlineElement::ELEMENT_TYPE_RECORD) {
+                throw new RootlineElementFormatException(
+                    'Can not add an element to an Access Rootline whose\' last element is a record type element.',
+                    1308343423
+                );
+            }
+        }
+
+        $this->rootlineElements[] = $rootlineElement;
+    }
+
+    /**
+     * Gets the Access Rootline for a specific page Id.
+     *
+     * @param int $pageId The page Id to generate the Access Rootline for.
+     * @param string $mountPointParameter The mount point parameter for generating the rootline.
+     * @return \WapplerSystems\Meilisearch\Access\Rootline Access Rootline for the given page Id.
+     */
+    public static function getAccessRootlineByPageId(
+        $pageId,
+        $mountPointParameter = ''
+    ) {
+        $accessRootline = GeneralUtility::makeInstance(Rootline::class);
+        $rootlineUtility = GeneralUtility::makeInstance(RootlineUtility::class, $pageId, $mountPointParameter);
+        try {
+            $rootline = $rootlineUtility->get();
+        } catch (\RuntimeException $e) {
+            $rootline = [];
+        }
+        $rootline = array_reverse($rootline);
+        // parent pages
+        foreach ($rootline as $pageRecord) {
+            if ($pageRecord['fe_group']
+                && $pageRecord['extendToSubpages']
+                && $pageRecord['uid'] != $pageId
+            ) {
+                $accessRootline->push(GeneralUtility::makeInstance(
+                    RootlineElement::class,
+                    /** @scrutinizer ignore-type */ $pageRecord['uid'] . RootlineElement::PAGE_ID_GROUP_DELIMITER . $pageRecord['fe_group']
+                ));
+            }
+        }
+
+            /** @var  $pageSelector PageRepository */
+        $pageSelector = GeneralUtility::makeInstance(PageRepository::class);
+
+        // current page
+        $currentPageRecord = $pageSelector->getPage($pageId, true);
+        if ($currentPageRecord['fe_group']) {
+            $accessRootline->push(GeneralUtility::makeInstance(
+                RootlineElement::class,
+                /** @scrutinizer ignore-type */ $currentPageRecord['uid'] . RootlineElement::PAGE_ID_GROUP_DELIMITER . $currentPageRecord['fe_group']
+            ));
+        }
+
+        return $accessRootline;
+    }
+
+    /**
+     * Returns the string representation of the access rootline.
+     *
+     * @return string String representation of the access rootline.
+     */
+    public function __toString()
+    {
+        $stringElements = [];
+
+        foreach ($this->rootlineElements as $rootlineElement) {
+            $stringElements[] = (string)$rootlineElement;
+        }
+
+        return implode(self::ELEMENT_DELIMITER, $stringElements);
+    }
+
+    /**
+     * Gets a the groups in the Access Rootline.
+     *
+     * @return array An array of sorted, unique user group IDs required to access a page.
+     */
+    public function getGroups()
+    {
+        $groups = [];
+
+        foreach ($this->rootlineElements as $rootlineElement) {
+            $rootlineElementGroups = $rootlineElement->getGroups();
+            $groups = array_merge($groups, $rootlineElementGroups);
+        }
+
+        $groups = $this->cleanGroupArray($groups);
+
+        return $groups;
+    }
+
+    /**
+     * Cleans an array of frontend user group IDs. Removes duplicates and sorts
+     * the array.
+     *
+     * @param array $groups An array of frontend user group IDs
+     * @return array An array of cleaned frontend user group IDs, unique, sorted.
+     */
+    public static function cleanGroupArray(array $groups)
+    {
+        $groups = array_unique($groups); // removes duplicates
+        sort($groups, SORT_NUMERIC); // sort
+
+        return $groups;
+    }
+}

Classes/Access/RootlineElement.php

@@ -0,0 +1,187 @@
+<?php
+namespace WapplerSystems\Meilisearch\Access;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * An element in the "Access Rootline". Represents the frontend user group
+ * access restrictions for a page, a page's content, or a generic record.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class RootlineElement
+{
+
+    /**
+     * Page access rootline element.
+     *
+     * @var int
+     */
+    const ELEMENT_TYPE_PAGE = 1;
+
+    /**
+     * Content access rootline element.
+     *
+     * @var int
+     */
+    const ELEMENT_TYPE_CONTENT = 2;
+
+    /**
+     * Record access rootline element.
+     *
+     * @var int
+     */
+    const ELEMENT_TYPE_RECORD = 3;
+
+    /**
+     * Delimiter between the page ID and the groups set for a page.
+     *
+     * @var string
+     */
+    const PAGE_ID_GROUP_DELIMITER = ':';
+
+    /**
+     * Access type, either page (default) or content. Depending on the type,
+     * access is granted differently. For pages the user must meet at least one
+     * group requirement, for content all group requirements must be met.
+     *
+     * @var int
+     */
+    protected $type = self::ELEMENT_TYPE_PAGE;
+
+    /**
+     * Page Id for the element. NULL for the content type.
+     *
+     * @var int
+     */
+    protected $pageId = null;
+
+    /**
+     * Set of access groups assigned to the element.
+     *
+     * @var array
+     */
+    protected $accessGroups = [];
+
+    /**
+     * Constructor for RootlineElement.
+     *
+     * @param string $element String representation of an element in the access rootline, usually of the form pageId:commaSeparatedPageAccessGroups
+     * @throws    RootlineElementFormatException on wrong access format.
+     */
+    public function __construct($element)
+    {
+        $elementAccess = explode(self::PAGE_ID_GROUP_DELIMITER, $element);
+
+        if (count($elementAccess) === 1 || $elementAccess[0] === 'c') {
+            // the content access groups part of the access rootline
+            $this->type = self::ELEMENT_TYPE_CONTENT;
+
+            if (count($elementAccess) === 1) {
+                $elementGroups = $elementAccess[0];
+            } else {
+                $elementGroups = $elementAccess[1];
+            }
+        } elseif ($elementAccess[0] === 'r') {
+            // record element type
+            if (count($elementAccess) !== 2) {
+                throw new RootlineElementFormatException(
+                    'Wrong Access Rootline Element format for a record type element.',
+                    1308342937
+                );
+            }
+
+            $this->type = self::ELEMENT_TYPE_RECORD;
+            $elementGroups = $elementAccess[1];
+        } else {
+            // page element type
+            if (count($elementAccess) !== 2 || !is_numeric($elementAccess[0])) {
+                throw new RootlineElementFormatException(
+                    'Wrong Access Rootline Element format for a page type element.',
+                    1294421105
+                );
+            }
+
+            $this->pageId = intval($elementAccess[0]);
+            $elementGroups = $elementAccess[1];
+        }
+
+        $this->accessGroups = GeneralUtility::intExplode(',', $elementGroups);
+    }
+
+    /**
+     * Returns the String representation of an access rootline element.
+     *
+     * @return string Access Rootline Element string representation
+     */
+    public function __toString()
+    {
+        $rootlineElement = '';
+
+        if ($this->type == self::ELEMENT_TYPE_CONTENT) {
+            $rootlineElement .= 'c';
+        } elseif ($this->type == self::ELEMENT_TYPE_RECORD) {
+            $rootlineElement .= 'r';
+        } else {
+            $rootlineElement .= $this->pageId;
+        }
+
+        $rootlineElement .= self::PAGE_ID_GROUP_DELIMITER;
+        $rootlineElement .= implode(',', $this->accessGroups);
+
+        return $rootlineElement;
+    }
+
+    /**
+     * Gets the access rootline element's type.
+     *
+     * @return int ELEMENT_TYPE_PAGE for page, ELEMENT_TYPE_CONTENT for content access rootline elements
+     */
+    public function getType()
+    {
+        return $this->type;
+    }
+
+    /**
+     * Gets the page Id for page type elements.
+     *
+     * @return int Page Id.
+     */
+    public function getPageId()
+    {
+        return $this->pageId;
+    }
+
+    /**
+     * Gets the element's access group restrictions.
+     *
+     * @return array Array of user group Ids
+     */
+    public function getGroups()
+    {
+        return $this->accessGroups;
+    }
+}

Classes/Access/RootlineElementFormatException.php

@@ -0,0 +1,34 @@
+<?php
+namespace WapplerSystems\Meilisearch\Access;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+/**
+ * Signals a wrong format for the access definition of a page or the content.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class RootlineElementFormatException extends \InvalidArgumentException
+{
+}

Classes/AdditionalFieldsIndexer.php

@@ -0,0 +1,126 @@
+<?php
+namespace WapplerSystems\Meilisearch;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\System\ContentObject\ContentObjectService;
+use WapplerSystems\Meilisearch\System\Solr\Document\Document;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Additional fields indexer.
+ *
+ * @todo Move this to an Index Queue frontend helper
+ *
+ * Adds page document fields as configured in
+ * plugin.tx_meilisearch.index.additionalFields.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class AdditionalFieldsIndexer implements SubstitutePageIndexer
+{
+
+    /**
+     * @var TypoScriptConfiguration
+     */
+    protected $configuration;
+
+    /**
+     * @var array
+     */
+    protected $additionalIndexingFields = [];
+
+    /**
+     * @var array
+     */
+    protected $additionalFieldNames = [];
+
+    /**
+     * @var ContentObjectService
+     */
+    protected $contentObjectService = null;
+
+    /**
+     * @param TypoScriptConfiguration $configuration
+     * @param ContentObjectService $contentObjectService
+     */
+    public function __construct(TypoScriptConfiguration $configuration = null, ContentObjectService $contentObjectService = null)
+    {
+        $this->configuration = $configuration === null ? Util::getSolrConfiguration() : $configuration;
+        $this->additionalIndexingFields = $this->configuration->getIndexAdditionalFieldsConfiguration();
+        $this->additionalFieldNames = $this->configuration->getIndexMappedAdditionalFieldNames();
+        $this->contentObjectService = $contentObjectService === null ? GeneralUtility::makeInstance(ContentObjectService::class) : $contentObjectService;
+    }
+
+    /**
+     * Returns a substitute document for the currently being indexed page.
+     *
+     * Uses the original document and adds fields as defined in
+     * plugin.tx_meilisearch.index.additionalFields.
+     *
+     * @param Document $pageDocument The original page document.
+     * @return Document A Apache Solr Document object that replace the default page document
+     */
+    public function getPageDocument(Document $pageDocument)
+    {
+        $substitutePageDocument = clone $pageDocument;
+        $additionalFields = $this->getAdditionalFields();
+
+        foreach ($additionalFields as $fieldName => $fieldValue) {
+            if (!isset($pageDocument->{$fieldName})) {
+                // making sure we only _add_ new fields
+                $substitutePageDocument->setField($fieldName, $fieldValue);
+            }
+        }
+
+        return $substitutePageDocument;
+    }
+
+    /**
+     * Gets the additional fields as an array mapping field names to values.
+     *
+     * @return array An array mapping additional field names to their values.
+     */
+    protected function getAdditionalFields()
+    {
+        $additionalFields = [];
+
+        foreach ($this->additionalFieldNames as $additionalFieldName) {
+            $additionalFields[$additionalFieldName] = $this->getFieldValue($additionalFieldName);
+        }
+
+        return $additionalFields;
+    }
+
+    /**
+     * Uses the page's cObj instance to resolve the additional field's value.
+     *
+     * @param string $fieldName The name of the field to get.
+     * @return string The field's value.
+     */
+    protected function getFieldValue($fieldName)
+    {
+        return $this->contentObjectService->renderSingleContentObjectByArrayAndKey($this->additionalIndexingFields, $fieldName);
+    }
+}

Classes/AdditionalPageIndexer.php

@@ -0,0 +1,49 @@
+<?php
+namespace WapplerSystems\Meilisearch;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2012-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *  A copy is found in the textfile GPL.txt and important notices to the license
+ *  from the author is found in LICENSE.txt distributed with these scripts.
+ *
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Solr\Document\Document;
+
+/**
+ * Interface that defines the method an indexer must implement to provide
+ * additional documents to index for a page being indexed.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+interface AdditionalPageIndexer
+{
+
+    /**
+     * Provides additional documents that should be indexed together with a page.
+     *
+     * @param Document $pageDocument The original page document.
+     * @param array $allDocuments An array containing all the documents collected until here, including the page document
+     * @return array An array of additional \WapplerSystems\Meilisearch\System\Solr\Document\Document objects
+     */
+    public function getAdditionalPageDocuments(Document $pageDocument, array $allDocuments);
+}

Classes/Api.php

@@ -0,0 +1,58 @@
+<?php
+namespace WapplerSystems\Meilisearch;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2012-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+/**
+ * Remote API related methods
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class Api
+{
+
+    /**
+     * Checks whether a string is a valid API key.
+     *
+     * @param string $apiKey API key to check for validity
+     * @return bool TRUE if the API key is valid, FALSE otherwise
+     */
+    public static function isValidApiKey($apiKey)
+    {
+        return ($apiKey === self::getApiKey());
+    }
+
+    /**
+     * Generates the API key for the REST API
+     *
+     * @return string API key for this installation
+     */
+    public static function getApiKey()
+    {
+        return sha1(
+            $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] .
+            'tx_meilisearch_api'
+        );
+    }
+}

Classes/Backend/IndexingConfigurationSelectorField.php

@@ -0,0 +1,213 @@
+<?php
+namespace WapplerSystems\Meilisearch\Backend;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2013-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use TYPO3\CMS\Backend\Form\FormResultCompiler;
+use TYPO3\CMS\Backend\Form\NodeFactory;
+use TYPO3\CMS\Core\Imaging\IconFactory;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Index Queue indexing configuration selector form field.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class IndexingConfigurationSelectorField
+{
+
+    /**
+     * Site used to determine indexing configurations
+     *
+     * @var Site
+     */
+    protected $site;
+
+    /**
+     * Form element name
+     *
+     * @var string
+     */
+    protected $formElementName = 'tx_meilisearch-index-queue-indexing-configuration-selector';
+
+    /**
+     * Selected values
+     *
+     * @var array
+     */
+    protected $selectedValues = [];
+
+    /**
+     * Constructor
+     *
+     * @param Site $site The site to use to determine indexing configurations
+     */
+    public function __construct(Site $site = null)
+    {
+        $this->site = $site;
+    }
+
+    /**
+     * Sets the form element name.
+     *
+     * @param string $formElementName Form element name
+     */
+    public function setFormElementName($formElementName)
+    {
+        $this->formElementName = $formElementName;
+    }
+
+    /**
+     * Gets the form element name.
+     *
+     * @return string form element name
+     */
+    public function getFormElementName()
+    {
+        return $this->formElementName;
+    }
+
+    /**
+     * Sets the selected values.
+     *
+     * @param array $selectedValues
+     */
+    public function setSelectedValues(array $selectedValues)
+    {
+        $this->selectedValues = $selectedValues;
+    }
+
+    /**
+     * Gets the selected values.
+     *
+     * @return array
+     */
+    public function getSelectedValues()
+    {
+        return $this->selectedValues;
+    }
+
+    /**
+     * Renders a field to select which indexing configurations to initialize.
+     *
+     * Uses \TYPO3\CMS\Backend\Form\FormEngine.
+     *
+     * @return string Markup for the select field
+     */
+    public function render()
+    {
+        // transform selected values into the format used by TCEforms
+        $selectedValues = $this->selectedValues;
+        $tablesToIndex = $this->getIndexQueueConfigurationTableMap();
+
+        $formField = $this->renderSelectCheckbox($this->buildSelectorItems($tablesToIndex), $selectedValues);
+
+        // need to wrap the field in a TCEforms table to make the CSS apply
+        $form[] = '<div class="typo3-TCEforms tx_meilisearch-TCEforms">';
+        $form[] = $formField;
+        $form[] = '</div>';
+
+        return implode(LF, $form);
+    }
+
+    /**
+     * Builds a map of indexing configuration names to tables to to index.
+     *
+     * @return array Indexing configuration to database table map
+     */
+    protected function getIndexQueueConfigurationTableMap()
+    {
+        $indexingTableMap = [];
+
+        $solrConfiguration = $this->site->getSolrConfiguration();
+        $configurationNames = $solrConfiguration->getEnabledIndexQueueConfigurationNames();
+        foreach ($configurationNames as $configurationName) {
+            $indexingTableMap[$configurationName] = $solrConfiguration->getIndexQueueTableNameOrFallbackToConfigurationName($configurationName);
+        }
+
+        return $indexingTableMap;
+    }
+
+    /**
+     * Builds the items to render in the TCEforms select field.
+     *
+     * @param array $tablesToIndex A map of indexing configuration to database tables
+     *
+     * @return array Selectable items for the TCEforms select field
+     */
+    protected function buildSelectorItems(array $tablesToIndex)
+    {
+        $selectorItems = [];
+        $iconFactory = GeneralUtility::makeInstance(IconFactory::class);
+
+        foreach ($tablesToIndex as $configurationName => $tableName) {
+            $icon = $iconFactory->mapRecordTypeToIconIdentifier($tableName, []);
+
+            $labelTableName = '';
+            if ($configurationName !== $tableName) {
+                $labelTableName = ' (' . $tableName . ')';
+            }
+
+            $selectorItems[] = [$configurationName . $labelTableName, $configurationName, $icon];
+        }
+
+        return $selectorItems;
+    }
+
+    /**
+     * @param array $items
+     * @param string $selectedValues
+     *
+     * @return string
+     * @throws \TYPO3\CMS\Backend\Form\Exception
+     */
+    protected function renderSelectCheckbox($items, $selectedValues)
+    {
+        $parameterArray = [
+            'fieldChangeFunc' => [],
+            'itemFormElName' => $this->formElementName,
+            'itemFormElValue' => $selectedValues,
+            'fieldConf' => ['config' => ['items' => $items]],
+            'fieldTSConfig' => ['noMatchingValue_label' => '']
+        ];
+
+        $nodeFactory = GeneralUtility::makeInstance(NodeFactory::class);
+        $options = [
+            'renderType' => 'selectCheckBox', 'table' => 'tx_meilisearch_classes_backend_indexingconfigurationselector',
+            'fieldName' => 'additionalFields', 'databaseRow' => [], 'parameterArray' => $parameterArray
+        ];
+        $options['parameterArray']['fieldConf']['config']['items'] = $items;
+        $options['parameterArray']['fieldTSConfig']['noMatchingValue_label'] = '';
+
+        $selectCheckboxResult = $nodeFactory->create($options)->render();
+        $formResultCompiler = GeneralUtility::makeInstance(FormResultCompiler::class);
+        $formResultCompiler->mergeResult($selectCheckboxResult);
+
+        $formHtml = isset($selectCheckboxResult['html']) ? $selectCheckboxResult['html'] : '';
+        $content = $formResultCompiler->addCssFiles() . $formHtml . $formResultCompiler->printNeededJSFunctions();
+
+        return $content;
+    }
+}

Classes/Backend/SiteSelectorField.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Backend;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 - Thomas Hohn <tho@systime.dk>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * SiteSelectorField
+ *
+ * Responsible for generating SiteSelectorField
+ *
+ * @author Thomas Hohn <tho@systime.dk>
+ */
+class SiteSelectorField
+{
+    /**
+     * Creates a dropdown selector of available TYPO3 sites with Solr configured.
+     *
+     * @param string $selectorName Name to be used in the select's name attribute
+     * @param Site $selectedSite Optional, currently selected site
+     * @return string Site selector HTML code
+     */
+    public function getAvailableSitesSelector(
+        $selectorName,
+        Site $selectedSite = null
+    ) {
+        $siteRepository = GeneralUtility::makeInstance(SiteRepository::class);
+
+        $sites = $siteRepository->getAvailableSites();
+        $selector = '<select name="' . htmlspecialchars($selectorName) . '" class="form-control">';
+
+        foreach ($sites as $site) {
+            $selectedAttribute = '';
+            if ($selectedSite !== null && $site->getRootPageId() === $selectedSite->getRootPageId()) {
+                $selectedAttribute = ' selected="selected"';
+            }
+
+            $selector .= '<option value="' . htmlspecialchars($site->getRootPageId()) . '"' . $selectedAttribute . '>'
+                . htmlspecialchars($site->getLabel())
+                . '</option>';
+        }
+
+        $selector .= '</select>';
+
+        return $selector;
+    }
+}

Classes/ConnectionManager.php

@@ -0,0 +1,267 @@
+<?php
+namespace WapplerSystems\Meilisearch;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\System\Records\Pages\PagesRepository as PagesRepositoryAtExtSolr;
+use WapplerSystems\Meilisearch\System\Records\SystemLanguage\SystemLanguageRepository;
+use WapplerSystems\Meilisearch\System\Solr\Node;
+use WapplerSystems\Meilisearch\System\Solr\SolrConnection;
+use InvalidArgumentException;
+use TYPO3\CMS\Core\Registry;
+use TYPO3\CMS\Core\SingletonInterface;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use function json_encode;
+
+/**
+ * ConnectionManager is responsible to create SolrConnection objects.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class ConnectionManager implements SingletonInterface
+{
+
+    /**
+     * @var array
+     */
+    protected static $connections = [];
+
+    /**
+     * @var SystemLanguageRepository
+     */
+    protected $systemLanguageRepository;
+
+    /**
+     * @var PagesRepositoryAtExtSolr
+     */
+    protected $pagesRepositoryAtExtSolr;
+
+    /**
+     * @var SiteRepository
+     */
+    protected $siteRepository;
+
+
+    /**
+     * @param SystemLanguageRepository $systemLanguageRepository
+     * @param PagesRepositoryAtExtSolr|null $pagesRepositoryAtExtSolr
+     * @param SiteRepository $siteRepository
+     */
+    public function __construct(
+        SystemLanguageRepository $systemLanguageRepository = null,
+        PagesRepositoryAtExtSolr $pagesRepositoryAtExtSolr = null,
+        SiteRepository $siteRepository = null
+    )
+    {
+        $this->systemLanguageRepository = $systemLanguageRepository ?? GeneralUtility::makeInstance(SystemLanguageRepository::class);
+        $this->siteRepository           = $siteRepository ?? GeneralUtility::makeInstance(SiteRepository::class);
+        $this->pagesRepositoryAtExtSolr = $pagesRepositoryAtExtSolr ?? GeneralUtility::makeInstance(PagesRepositoryAtExtSolr::class);
+    }
+
+    /**
+     * Creates a solr connection for read and write endpoints
+     *
+     * @param array $readNodeConfiguration
+     * @param array $writeNodeConfiguration
+     * @return SolrConnection|object
+     */
+    public function getSolrConnectionForNodes(array $readNodeConfiguration, array $writeNodeConfiguration)
+    {
+        $connectionHash = md5(json_encode($readNodeConfiguration) .  json_encode($writeNodeConfiguration));
+        if (!isset(self::$connections[$connectionHash])) {
+            $readNode = Node::fromArray($readNodeConfiguration);
+            $writeNode = Node::fromArray($writeNodeConfiguration);
+            self::$connections[$connectionHash] = GeneralUtility::makeInstance(SolrConnection::class, $readNode, $writeNode);
+        }
+        return self::$connections[$connectionHash];
+    }
+
+    /**
+     * Creates a solr configuration from the configuration array and returns it.
+     *
+     * @param array $config The solr configuration array
+     * @return SolrConnection
+     */
+    public function getConnectionFromConfiguration(array $config)
+    {
+        if(empty($config['read']) && !empty($config['solrHost'])) {
+            throw new InvalidArgumentException('Invalid registry data please re-initialize your solr connections');
+        }
+
+        return $this->getSolrConnectionForNodes($config['read'], $config['write']);
+    }
+
+    /**
+     * Gets a Solr connection for a page ID.
+     *
+     * @param int $pageId A page ID.
+     * @param int $language The language ID to get the connection for as the path may differ. Optional, defaults to 0.
+     * @param string $mount Comma list of MountPoint parameters
+     * @return SolrConnection A solr connection.
+     * @throws NoSolrConnectionFoundException
+     */
+    public function getConnectionByPageId($pageId, $language = 0, $mount = '')
+    {
+        try {
+            $site = $this->siteRepository->getSiteByPageId($pageId, $mount);
+            $this->throwExceptionOnInvalidSite($site, 'No site for pageId ' . $pageId);
+            $config = $site->getSolrConnectionConfiguration($language);
+            $solrConnection = $this->getConnectionFromConfiguration($config);
+            return $solrConnection;
+        } catch(InvalidArgumentException $e) {
+            $noSolrConnectionException = $this->buildNoConnectionExceptionForPageAndLanguage($pageId, $language);
+            throw $noSolrConnectionException;
+        }
+    }
+
+    /**
+     * Gets a Solr connection for a root page ID.
+     *
+     * @param int $pageId A root page ID.
+     * @param int $language The language ID to get the connection for as the path may differ. Optional, defaults to 0.
+     * @return SolrConnection A solr connection.
+     * @throws NoSolrConnectionFoundException
+     */
+    public function getConnectionByRootPageId($pageId, $language = 0)
+    {
+        try {
+            $site = $this->siteRepository->getSiteByRootPageId($pageId);
+            $this->throwExceptionOnInvalidSite($site, 'No site for pageId ' . $pageId);
+            $config = $site->getSolrConnectionConfiguration($language);
+            $solrConnection = $this->getConnectionFromConfiguration($config);
+            return $solrConnection;
+        } catch (InvalidArgumentException $e) {
+            /* @var NoSolrConnectionFoundException $noSolrConnectionException */
+            $noSolrConnectionException = $this->buildNoConnectionExceptionForPageAndLanguage($pageId, $language);
+            throw $noSolrConnectionException;
+        }
+    }
+
+    /**
+     * Gets all connections found.
+     *
+     * @return SolrConnection[] An array of initialized WapplerSystems\Meilisearch\System\Solr\SolrConnection connections
+     * @throws NoSolrConnectionFoundException
+     */
+    public function getAllConnections()
+    {
+        $solrConnections = [];
+        foreach ($this->siteRepository->getAvailableSites() as $site) {
+            foreach ($site->getAllSolrConnectionConfigurations() as $solrConfiguration) {
+                $solrConnections[] = $this->getConnectionFromConfiguration($solrConfiguration);
+            }
+        }
+
+        return $solrConnections;
+    }
+
+    /**
+     * Gets all connections configured for a given site.
+     *
+     * @param Site $site A TYPO3 site
+     * @return SolrConnection[] An array of Solr connection objects (WapplerSystems\Meilisearch\System\Solr\SolrConnection)
+     * @throws NoSolrConnectionFoundException
+     */
+    public function getConnectionsBySite(Site $site)
+    {
+        $connections = [];
+
+        foreach ($site->getAllSolrConnectionConfigurations() as $languageId => $solrConnectionConfiguration) {
+            $connections[$languageId] = $this->getConnectionFromConfiguration($solrConnectionConfiguration);
+        }
+
+        return $connections;
+    }
+
+    /**
+     * Creates a human readable label from the connections' configuration.
+     *
+     * @param array $connection Connection configuration
+     * @return string Connection label
+     */
+    protected function buildConnectionLabel(array $connection)
+    {
+        return $connection['rootPageTitle']
+            . ' (pid: ' . $connection['rootPageUid']
+            . ', language: ' . $this->systemLanguageRepository->findOneLanguageTitleByLanguageId($connection['language'])
+            . ') - Read node: '
+            . $connection['read']['host'] . ':'
+            . $connection['read']['port']
+            . $connection['read']['path']
+            .' - Write node: '
+            . $connection['write']['host'] . ':'
+            . $connection['write']['port']
+            . $connection['write']['path'];
+    }
+
+    /**
+     * @param $pageId
+     * @param $language
+     * @return NoSolrConnectionFoundException
+     */
+    protected function buildNoConnectionExceptionForPageAndLanguage($pageId, $language): NoSolrConnectionFoundException
+    {
+        $message = 'Could not find a Solr connection for page [' . $pageId . '] and language [' . $language . '].';
+        $noSolrConnectionException = $this->buildNoConnectionException($message);
+
+        $noSolrConnectionException->setLanguageId($language);
+        return $noSolrConnectionException;
+    }
+
+    /**
+     * Throws a no connection exception when no site was passed.
+     *
+     * @param Site|null $site
+     * @param $message
+     * @throws NoSolrConnectionFoundException
+     */
+    protected function throwExceptionOnInvalidSite(?Site $site, string $message)
+    {
+        if (!is_null($site)) {
+            return;
+        }
+
+        throw $this->buildNoConnectionException($message);
+    }
+
+    /**
+     * Build a NoSolrConnectionFoundException with the passed message.
+     * @param string $message
+     * @return NoSolrConnectionFoundException
+     */
+    protected function buildNoConnectionException(string $message): NoSolrConnectionFoundException
+    {
+        /* @var NoSolrConnectionFoundException $noSolrConnectionException */
+        $noSolrConnectionException = GeneralUtility::makeInstance(
+            NoSolrConnectionFoundException::class,
+            /** @scrutinizer ignore-type */
+            $message,
+            /** @scrutinizer ignore-type */
+            1575396474
+        );
+        return $noSolrConnectionException;
+    }
+}

Classes/ContentObject/Classification.php

@@ -0,0 +1,117 @@
+<?php
+namespace WapplerSystems\Meilisearch\ContentObject;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Index\Classification\Classification as ClassificationItem;
+use WapplerSystems\Meilisearch\Domain\Index\Classification\ClassificationService;
+use InvalidArgumentException;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\ContentObject\AbstractContentObject;
+
+/**
+ * A content object (cObj) to classify content based on a configuration.
+ *
+ * Example usage:
+ *
+ * keywords = SOLR_CLASSIFICATION # supports stdWrap
+ * keywords {
+ *   field = __solr_content # a comma separated field. instead of field you can also use "value"
+ *   classes {
+ *     1 {
+ *        patterns = smartphone, mobile, mobilephone # list of patterns that need to match to assign that class
+ *        class = mobilephone # class that should be assigned when a pattern matches
+ *     }
+ *   }
+ * }
+ */
+class Classification extends AbstractContentObject
+{
+    const CONTENT_OBJECT_NAME = 'SOLR_CLASSIFICATION';
+
+    /**
+     * Executes the SOLR_CLASSIFICATION content object.
+     *
+     * Returns mapped classes when the field matches on of the configured patterns ...
+     *
+     * @inheritDoc
+     */
+    public function render($conf = [])
+    {
+
+        if (!is_array($conf['classes.'])) {
+            throw new InvalidArgumentException('No class configuration configured for SOLR_CLASSIFICATION object. Given configuration: ' . serialize($conf));
+        }
+
+        $configuredMappedClasses = $conf['classes.'];
+        unset($conf['classes.']);
+
+        $data = '';
+        if (isset($conf['value'])) {
+            $data = $conf['value'];
+            unset($conf['value']);
+        }
+
+        if (!empty($conf)) {
+            $data = $this->cObj->stdWrap($data, $conf);
+        }
+        $classifications = $this->buildClassificationsFromConfiguration($configuredMappedClasses);
+        /** @var $classificationService ClassificationService */
+        $classificationService = GeneralUtility::makeInstance(ClassificationService::class);
+
+        return serialize($classificationService->getMatchingClassNames((string)$data, $classifications));
+    }
+
+    /**
+     * Builds an array of Classification objects from the passed classification configuration.
+     *
+     * @param array $configuredMappedClasses
+     * @return ClassificationItem[]
+     */
+    protected function buildClassificationsFromConfiguration($configuredMappedClasses) : array
+    {
+        $classifications = [];
+        foreach ($configuredMappedClasses as $class) {
+            if ( (empty($class['patterns']) && empty($class['matchPatterns'])) || empty($class['class'])) {
+                throw new InvalidArgumentException('A class configuration in SOLR_CLASSIFCATION needs to have a pattern and a class configured. Given configuration: ' . serialize($class));
+            }
+
+                // @todo deprecate patterns configuration
+            $patterns = empty($class['patterns']) ? [] : GeneralUtility::trimExplode(',', $class['patterns']);
+            $matchPatterns = empty($class['matchPatterns']) ? [] : GeneralUtility::trimExplode(',', $class['matchPatterns']);
+            $matchPatterns = $matchPatterns + $patterns;
+            $unMatchPatters = empty($class['unmatchPatterns']) ? [] : GeneralUtility::trimExplode(',', $class['unmatchPatterns']);
+
+            $className = $class['class'];
+            $classifications[] = GeneralUtility::makeInstance(
+                ClassificationItem::class,
+                /** @scrutinizer ignore-type */ $matchPatterns,
+                /** @scrutinizer ignore-type */ $unMatchPatters,
+                /** @scrutinizer ignore-type */ $className
+            );
+        }
+
+        return $classifications;
+    }
+}

Classes/ContentObject/Content.php

@@ -0,0 +1,80 @@
+<?php
+namespace WapplerSystems\Meilisearch\ContentObject;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\HtmlContentExtractor;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\ContentObject\AbstractContentObject;
+use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
+
+/**
+ * A content object (cObj) to clean a database field in a way so that it can be
+ * used to fill a Solr document's content field.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class Content extends AbstractContentObject
+{
+    const CONTENT_OBJECT_NAME = 'SOLR_CONTENT';
+
+    /**
+     * Executes the SOLR_CONTENT content object.
+     *
+     * Cleans content coming from a database field, removing HTML tags ...
+     *
+     * @inheritDoc
+     */
+    public function render($conf = [])
+    {
+        $contentExtractor = GeneralUtility::makeInstance(
+            HtmlContentExtractor::class,
+            /** @scrutinizer ignore-type */ $this->getRawContent($this->cObj, $conf)
+        );
+
+        return $contentExtractor->getIndexableContent();
+    }
+
+    /**
+     * Gets the raw content as configured - a certain value or database field.
+     *
+     * @param ContentObjectRenderer $contentObject The original content object
+     * @param array $configuration content object configuration
+     * @return string The raw content
+     */
+    protected function getRawContent($contentObject, $configuration)
+    {
+        $content = '';
+        if (isset($configuration['value'])) {
+            $content = $configuration['value'];
+            unset($configuration['value']);
+        }
+
+        if (!empty($configuration)) {
+            $content = $contentObject->stdWrap($content, $configuration);
+        }
+
+        return $content;
+    }
+}

Classes/ContentObject/Multivalue.php

@@ -0,0 +1,92 @@
+<?php
+namespace WapplerSystems\Meilisearch\ContentObject;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\ContentObject\AbstractContentObject;
+
+/**
+ * A content object (cObj) to turn comma separated strings into an array to be
+ * used in a multi value field in a Solr document.
+ *
+ * Example usage:
+ *
+ * keywords = SOLR_MULTIVALUE # supports stdWrap
+ * keywords {
+ *   field = tags # a comma separated field. instead of field you can also use "value"
+ *   separator = , # comma is the default value
+ *   removeEmptyValues = 1 # a flag to remove empty strings from the list, on by default.
+ *   removeDuplicateValues = 1 # a flag to remove duplicate strings from the list, off by default.
+ * }
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class Multivalue extends AbstractContentObject
+{
+    const CONTENT_OBJECT_NAME = 'SOLR_MULTIVALUE';
+
+    /**
+     * Executes the SOLR_MULTIVALUE content object.
+     *
+     * Turns a list of values into an array that can then be used to fill
+     * multivalued fields in a Solr document. The array is returned in
+     * serialized form as content objects are expected to return strings.
+     *
+     * @inheritDoc
+     */
+    public function render($conf = [])
+    {
+        $data = '';
+        if (isset($conf['value'])) {
+            $data = $conf['value'];
+            unset($conf['value']);
+        }
+
+        if (!empty($conf)) {
+            $data = $this->cObj->stdWrap($data, $conf);
+        }
+
+        if (!array_key_exists('separator', $conf)) {
+            $conf['separator'] = ',';
+        }
+
+        $removeEmptyValues = true;
+        if (isset($conf['removeEmptyValues']) && $conf['removeEmptyValues'] == 0) {
+            $removeEmptyValues = false;
+        }
+
+        $listAsArray = GeneralUtility::trimExplode(
+            $conf['separator'],
+            $data,
+            $removeEmptyValues
+        );
+
+        if (!empty($conf['removeDuplicateValues'])) {
+            $listAsArray = array_unique($listAsArray);
+        }
+
+        return serialize($listAsArray);
+    }
+}

Classes/ContentObject/Relation.php

@@ -0,0 +1,385 @@
+<?php
+namespace WapplerSystems\Meilisearch\ContentObject;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2011-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Language\FrontendOverlayService;
+use WapplerSystems\Meilisearch\System\TCA\TCAService;
+use WapplerSystems\Meilisearch\Util;
+use Doctrine\DBAL\Driver\Statement;
+use TYPO3\CMS\Core\Database\ConnectionPool;
+use TYPO3\CMS\Core\Database\Query\QueryBuilder;
+use TYPO3\CMS\Core\Database\RelationHandler;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\ContentObject\AbstractContentObject;
+use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
+
+/**
+ * A content object (cObj) to resolve relations between database records
+ *
+ * Configuration options:
+ *
+ * localField: the record's field to use to resolve relations
+ * foreignLabelField: Usually the label field to retrieve from the related records is determined automatically using TCA, using this option the desired field can be specified explicitly
+ * multiValue: whether to return related records suitable for a multi value field
+ * singleValueGlue: when not using multiValue, the related records need to be concatenated using a glue string, by default this is ", ". Using this option a custom glue can be specified. The custom value must be wrapped by pipe (|) characters.
+ * relationTableSortingField: field in an mm relation table to sort by, usually "sorting"
+ * enableRecursiveValueResolution: if the specified remote table's label field is a relation to another table, the value will be resolve by following the relation recursively.
+ * removeEmptyValues: Removes empty values when resolving relations, defaults to TRUE
+ * removeDuplicateValues: Removes duplicate values
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class Relation extends AbstractContentObject
+{
+    const CONTENT_OBJECT_NAME = 'SOLR_RELATION';
+
+    /**
+     * Content object configuration
+     *
+     * @var array
+     */
+    protected $configuration = [];
+
+    /**
+     * @var TCAService
+     */
+    protected $tcaService = null;
+
+    /**
+     * @var FrontendOverlayService
+     */
+    protected $frontendOverlayService = null;
+
+    /**
+     * Relation constructor.
+     * @param TCAService|null $tcaService
+     * @param FrontendOverlayService|null $frontendOverlayService
+     */
+    public function __construct(ContentObjectRenderer $cObj, TCAService $tcaService = null, FrontendOverlayService $frontendOverlayService = null)
+    {
+        $this->cObj = $cObj;
+        $this->configuration['enableRecursiveValueResolution'] = 1;
+        $this->configuration['removeEmptyValues'] = 1;
+        $this->tcaService = $tcaService ?? GeneralUtility::makeInstance(TCAService::class);
+        $this->frontendOverlayService = $frontendOverlayService ?? GeneralUtility::makeInstance(FrontendOverlayService::class);
+    }
+
+    /**
+     * Executes the SOLR_RELATION content object.
+     *
+     * Resolves relations between records. Currently supported relations are
+     * TYPO3-style m:n relations.
+     * May resolve single value and multi value relations.
+     *
+     * @inheritDoc
+     */
+    public function render($conf = [])
+    {
+        $this->configuration = array_merge($this->configuration, $conf);
+
+        $relatedItems = $this->getRelatedItems($this->cObj);
+
+        if (!empty($this->configuration['removeDuplicateValues'])) {
+            $relatedItems = array_unique($relatedItems);
+        }
+
+        if (empty($conf['multiValue'])) {
+            // single value, need to concatenate related items
+            $singleValueGlue = !empty($conf['singleValueGlue']) ? trim($conf['singleValueGlue'], '|') : ', ';
+            $result = implode($singleValueGlue, $relatedItems);
+        } else {
+            // multi value, need to serialize as content objects must return strings
+            $result = serialize($relatedItems);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Gets the related items of the current record's configured field.
+     *
+     * @param ContentObjectRenderer $parentContentObject parent content object
+     * @return array Array of related items, values already resolved from related records
+     */
+    protected function getRelatedItems(ContentObjectRenderer $parentContentObject)
+    {
+        list($table, $uid) = explode(':', $parentContentObject->currentRecord);
+        $uid = (int) $uid;
+        $field = $this->configuration['localField'];
+
+        if (!$this->tcaService->getHasConfigurationForField($table, $field)) {
+            return [];
+        }
+
+        $overlayUid = $this->frontendOverlayService->getUidOfOverlay($table, $field, $uid);
+        $fieldTCA = $this->tcaService->getConfigurationForField($table, $field);
+
+        if (isset($fieldTCA['config']['MM']) && trim($fieldTCA['config']['MM']) !== '') {
+            $relatedItems = $this->getRelatedItemsFromMMTable($table, $overlayUid, $fieldTCA);
+        } else {
+            $relatedItems = $this->getRelatedItemsFromForeignTable($table, $overlayUid, $fieldTCA, $parentContentObject);
+        }
+
+        return $relatedItems;
+    }
+
+    /**
+     * Gets the related items from a table using a n:m relation.
+     *
+     * @param string $localTableName Local table name
+     * @param int $localRecordUid Local record uid
+     * @param array $localFieldTca The local table's TCA
+     * @return array Array of related items, values already resolved from related records
+     */
+    protected function getRelatedItemsFromMMTable($localTableName, $localRecordUid, array $localFieldTca)
+    {
+        $relatedItems = [];
+        $foreignTableName = $localFieldTca['config']['foreign_table'];
+        $foreignTableTca = $this->tcaService->getTableConfiguration($foreignTableName);
+        $foreignTableLabelField = $this->resolveForeignTableLabelField($foreignTableTca);
+        $mmTableName = $localFieldTca['config']['MM'];
+
+        // Remove the first option of foreignLabelField for recursion
+        if (strpos($this->configuration['foreignLabelField'], '.') !== false) {
+            $foreignTableLabelFieldArr = explode('.', $this->configuration['foreignLabelField']);
+            unset($foreignTableLabelFieldArr[0]);
+            $this->configuration['foreignLabelField'] = implode('.', $foreignTableLabelFieldArr);
+        }
+
+        $relationHandler = GeneralUtility::makeInstance(RelationHandler::class);
+        $relationHandler->start('', $foreignTableName, $mmTableName, $localRecordUid, $localTableName, $localFieldTca['config']);
+        $selectUids = $relationHandler->tableArray[$foreignTableName];
+        if (!is_array($selectUids) || count($selectUids) <= 0) {
+            return $relatedItems;
+        }
+
+        $relatedRecords = $this->getRelatedRecords($foreignTableName, ...$selectUids);
+        foreach ($relatedRecords as $record) {
+            if (isset($foreignTableTca['columns'][$foreignTableLabelField]['config']['foreign_table'])
+                && $this->configuration['enableRecursiveValueResolution']
+            ) {
+                if (strpos($this->configuration['foreignLabelField'], '.') !== false) {
+                    $foreignTableLabelFieldArr = explode('.', $this->configuration['foreignLabelField']);
+                    unset($foreignTableLabelFieldArr[0]);
+                    $this->configuration['foreignLabelField'] = implode('.', $foreignTableLabelFieldArr);
+                }
+
+                $this->configuration['localField'] = $foreignTableLabelField;
+
+                $contentObject = GeneralUtility::makeInstance(ContentObjectRenderer::class);
+                $contentObject->start($record, $foreignTableName);
+
+                return $this->getRelatedItems($contentObject);
+            } else {
+                if (Util::getLanguageUid() > 0) {
+                    $record = $this->frontendOverlayService->getOverlay($foreignTableName, $record);
+                }
+                $relatedItems[] = $record[$foreignTableLabelField];
+            }
+        }
+
+        return $relatedItems;
+    }
+
+    /**
+     * Resolves the field to use as the related item's label depending on TCA
+     * and TypoScript configuration
+     *
+     * @param array $foreignTableTca The foreign table's TCA
+     * @return string The field to use for the related item's label
+     */
+    protected function resolveForeignTableLabelField(array $foreignTableTca)
+    {
+        $foreignTableLabelField = $foreignTableTca['ctrl']['label'];
+
+        // when foreignLabelField is not enabled we can return directly
+        if (empty($this->configuration['foreignLabelField'])) {
+            return $foreignTableLabelField;
+        }
+
+        if (strpos($this->configuration['foreignLabelField'], '.') !== false) {
+            list($foreignTableLabelField) = explode('.', $this->configuration['foreignLabelField'], 2);
+        } else {
+            $foreignTableLabelField = $this->configuration['foreignLabelField'];
+        }
+
+        return $foreignTableLabelField;
+    }
+
+    /**
+     * Gets the related items from a table using a 1:n relation.
+     *
+     * @param string $localTableName Local table name
+     * @param int $localRecordUid Local record uid
+     * @param array $localFieldTca The local table's TCA
+     * @param ContentObjectRenderer $parentContentObject parent content object
+     * @return array Array of related items, values already resolved from related records
+     */
+    protected function getRelatedItemsFromForeignTable(
+        $localTableName,
+        $localRecordUid,
+        array $localFieldTca,
+        ContentObjectRenderer $parentContentObject
+    ) {
+        $relatedItems = [];
+        $foreignTableName = $localFieldTca['config']['foreign_table'];
+        $foreignTableTca = $this->tcaService->getTableConfiguration($foreignTableName);
+        $foreignTableLabelField = $this->resolveForeignTableLabelField($foreignTableTca);
+
+            /** @var $relationHandler RelationHandler */
+        $relationHandler = GeneralUtility::makeInstance(RelationHandler::class);
+
+        $itemList = $parentContentObject->data[$this->configuration['localField']] ?? '';
+
+        $relationHandler->start($itemList, $foreignTableName, '', $localRecordUid, $localTableName, $localFieldTca['config']);
+        $selectUids = $relationHandler->tableArray[$foreignTableName];
+
+        if (!is_array($selectUids) || count($selectUids) <= 0) {
+            return $relatedItems;
+        }
+
+        $relatedRecords = $this->getRelatedRecords($foreignTableName, ...$selectUids);
+
+        foreach ($relatedRecords as $relatedRecord) {
+            $resolveRelatedValue = $this->resolveRelatedValue(
+                $relatedRecord,
+                $foreignTableTca,
+                $foreignTableLabelField,
+                $parentContentObject,
+                $foreignTableName
+            );
+            if (!empty($resolveRelatedValue) || !$this->configuration['removeEmptyValues']) {
+                $relatedItems[] = $resolveRelatedValue;
+            }
+        }
+
+        return $relatedItems;
+    }
+
+    /**
+     * Resolves the value of the related field. If the related field's value is
+     * a relation itself, this method takes care of resolving it recursively.
+     *
+     * @param array $relatedRecord Related record as array
+     * @param array $foreignTableTca TCA of the related table
+     * @param string $foreignTableLabelField Field name of the foreign label field
+     * @param ContentObjectRenderer $parentContentObject cObject
+     * @param string $foreignTableName Related record table name
+     *
+     * @return string
+     */
+    protected function resolveRelatedValue(
+        array $relatedRecord,
+        $foreignTableTca,
+        $foreignTableLabelField,
+        ContentObjectRenderer $parentContentObject,
+        $foreignTableName = ''
+    ) {
+        if (Util::getLanguageUid() > 0 && !empty($foreignTableName)) {
+            $relatedRecord = $this->frontendOverlayService->getOverlay($foreignTableName, $relatedRecord);
+        }
+
+        $value = $relatedRecord[$foreignTableLabelField];
+
+        if (
+            !empty($foreignTableName)
+            && isset($foreignTableTca['columns'][$foreignTableLabelField]['config']['foreign_table'])
+            && $this->configuration['enableRecursiveValueResolution']
+        ) {
+            // backup
+            $backupRecord = $parentContentObject->data;
+            $backupConfiguration = $this->configuration;
+
+            // adjust configuration for next level
+            $this->configuration['localField'] = $foreignTableLabelField;
+            $parentContentObject->data = $relatedRecord;
+            if (strpos($this->configuration['foreignLabelField'], '.') !== false) {
+                list(, $this->configuration['foreignLabelField']) = explode('.',
+                    $this->configuration['foreignLabelField'], 2);
+            } else {
+                $this->configuration['foreignLabelField'] = '';
+            }
+
+            // recursion
+            $relatedItemsFromForeignTable = $this->getRelatedItemsFromForeignTable(
+                $foreignTableName,
+                $relatedRecord['uid'],
+                $foreignTableTca['columns'][$foreignTableLabelField],
+                $parentContentObject
+            );
+            $value = array_pop($relatedItemsFromForeignTable);
+
+            // restore
+            $this->configuration = $backupConfiguration;
+            $parentContentObject->data = $backupRecord;
+        }
+
+        return $parentContentObject->stdWrap($value, $this->configuration);
+    }
+
+    /**
+     * Return records via relation.
+     *
+     * @param string $foreignTable The table to fetch records from.
+     * @param int[] ...$uids The uids to fetch from table.
+     * @return array
+     */
+    protected function getRelatedRecords($foreignTable, int ...$uids): array
+    {
+        /** @var QueryBuilder $queryBuilder */
+        $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable($foreignTable);
+        $queryBuilder->select('*')
+            ->from($foreignTable)
+            ->where($queryBuilder->expr()->in('uid', $uids));
+        if (isset($this->configuration['additionalWhereClause'])) {
+            $queryBuilder->andWhere($this->configuration['additionalWhereClause']);
+        }
+        $statement = $queryBuilder->execute();
+
+        return $this->sortByKeyInIN($statement, 'uid', ...$uids);
+    }
+
+    /**
+     * Sorts the result set by key in array for IN values.
+     *   Simulates MySqls ORDER BY FIELD(fieldname, COPY_OF_IN_FOR_WHERE)
+     *   Example: SELECT * FROM a_table WHERE field_name IN (2, 3, 4) SORT BY FIELD(field_name, 2, 3, 4)
+     *
+     *
+     * @param Statement $statement
+     * @param string $columnName
+     * @param array $arrayWithValuesForIN
+     * @return array
+     */
+    protected function sortByKeyInIN(Statement $statement, string $columnName, ...$arrayWithValuesForIN) : array
+    {
+        $records = [];
+        while ($record = $statement->fetch()) {
+            $indexNumber = array_search($record[$columnName], $arrayWithValuesForIN);
+            $records[$indexNumber] = $record;
+        }
+        ksort($records);
+        return $records;
+    }
+}

Classes/Controller/AbstractBaseController.php

@@ -0,0 +1,276 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSetService;
+use WapplerSystems\Meilisearch\Domain\Search\SearchRequestBuilder;
+use WapplerSystems\Meilisearch\NoSolrConnectionFoundException;
+use WapplerSystems\Meilisearch\Search;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\Mvc\Controller\SolrControllerContext;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use WapplerSystems\Meilisearch\System\Service\ConfigurationService;
+use WapplerSystems\Meilisearch\System\Configuration\ConfigurationManager as SolrConfigurationManager;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Core\TypoScript\TypoScriptService;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface;
+use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
+use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
+use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
+
+/**
+ * Class AbstractBaseController
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+abstract class AbstractBaseController extends ActionController
+{
+    /**
+     * @var ContentObjectRenderer
+     */
+    private $contentObjectRenderer;
+
+    /**
+     * @var TypoScriptFrontendController
+     */
+    protected $typoScriptFrontendController;
+
+    /**
+     * @var \TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface
+     */
+    protected $configurationManager;
+
+    /**
+     * @var SolrConfigurationManager
+     */
+    private $solrConfigurationManager;
+
+    /**
+     * The configuration is private if you need it please get it from the controllerContext.
+     *
+     * @var TypoScriptConfiguration
+     */
+    protected $typoScriptConfiguration;
+
+    /**
+     * @var \WapplerSystems\Meilisearch\Mvc\Controller\SolrControllerContext
+     */
+    protected $controllerContext;
+
+    /**
+     * @var \WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSetService
+     */
+    protected $searchService;
+
+    /**
+     * @var \WapplerSystems\Meilisearch\Domain\Search\SearchRequestBuilder
+     */
+    protected $searchRequestBuilder;
+
+    /**
+     * @var bool
+     */
+    protected $resetConfigurationBeforeInitialize = true;
+
+    /**
+     * @param \TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface $configurationManager
+     * @return void
+     */
+    public function injectConfigurationManager(ConfigurationManagerInterface $configurationManager)
+    {
+        $this->configurationManager = $configurationManager;
+        // @extensionScannerIgnoreLine
+        $this->contentObjectRenderer = $this->configurationManager->getContentObject();
+    }
+
+    /**
+     * @param \TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer $contentObjectRenderer
+     */
+    public function setContentObjectRenderer($contentObjectRenderer)
+    {
+        $this->contentObjectRenderer = $contentObjectRenderer;
+    }
+
+    /**
+     * @return \TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer
+     */
+    public function getContentObjectRenderer()
+    {
+        return $this->contentObjectRenderer;
+    }
+
+    /**
+     * @param SolrConfigurationManager $configurationManager
+     */
+    public function injectSolrConfigurationManager(SolrConfigurationManager $configurationManager)
+    {
+        $this->solrConfigurationManager = $configurationManager;
+    }
+
+    /**
+     * @param boolean $resetConfigurationBeforeInitialize
+     */
+    public function setResetConfigurationBeforeInitialize($resetConfigurationBeforeInitialize)
+    {
+        $this->resetConfigurationBeforeInitialize = $resetConfigurationBeforeInitialize;
+    }
+
+    /**
+     * Initialize the controller context
+     *
+     * @return \TYPO3\CMS\Extbase\Mvc\Controller\ControllerContext ControllerContext to be passed to the view
+     * @api
+     */
+    protected function buildControllerContext()
+    {
+        /** @var $controllerContext \WapplerSystems\Meilisearch\Mvc\Controller\SolrControllerContext */
+        $controllerContext = $this->objectManager->get(SolrControllerContext::class);
+        $controllerContext->setRequest($this->request);
+        $controllerContext->setResponse($this->response);
+        if ($this->arguments !== null) {
+            $controllerContext->setArguments($this->arguments);
+        }
+        $controllerContext->setUriBuilder($this->uriBuilder);
+
+        $controllerContext->setTypoScriptConfiguration($this->typoScriptConfiguration);
+
+        return $controllerContext;
+    }
+
+    /**
+     * Initialize action
+     */
+    protected function initializeAction()
+    {
+        // Reset configuration (to reset flexform overrides) if resetting is enabled
+        if ($this->resetConfigurationBeforeInitialize) {
+            $this->solrConfigurationManager->reset();
+        }
+        /** @var TypoScriptService $typoScriptService */
+        $typoScriptService = $this->objectManager->get(TypoScriptService::class);
+
+        // Merge settings done by typoscript with solrConfiguration plugin.tx_meilisearch (obsolete when part of ext:solr)
+        $frameWorkConfiguration = $this->configurationManager->getConfiguration(ConfigurationManagerInterface::CONFIGURATION_TYPE_FRAMEWORK);
+        $pluginSettings = [];
+        foreach (['search', 'settings', 'suggest', 'statistics', 'logging', 'general', 'solr', 'view'] as $key) {
+            if (isset($frameWorkConfiguration[$key])) {
+                $pluginSettings[$key] = $frameWorkConfiguration[$key];
+            }
+        }
+
+        $this->typoScriptConfiguration = $this->solrConfigurationManager->getTypoScriptConfiguration();
+        if ($pluginSettings !== []) {
+            $this->typoScriptConfiguration->mergeSolrConfiguration(
+                $typoScriptService->convertPlainArrayToTypoScriptArray($pluginSettings),
+                true,
+                false
+            );
+        }
+
+        $this->objectManager->get(ConfigurationService::class)
+            ->overrideConfigurationWithFlexFormSettings(
+                $this->contentObjectRenderer->data['pi_flexform'],
+                $this->typoScriptConfiguration
+            );
+
+        parent::initializeAction();
+        $this->typoScriptFrontendController = $GLOBALS['TSFE'];
+        $this->initializeSettings();
+
+        if ($this->actionMethodName !== 'solrNotAvailableAction') {
+            $this->initializeSearch();
+        }
+    }
+
+    /**
+     * Inject settings of plugin.tx_meilisearch
+     *
+     * @return void
+     */
+    protected function initializeSettings()
+    {
+        /** @var $typoScriptService TypoScriptService */
+        $typoScriptService = $this->objectManager->get(TypoScriptService::class);
+
+        // Make sure plugin.tx_meilisearch.settings are available in the view as {settings}
+        $this->settings = $typoScriptService->convertTypoScriptArrayToPlainArray(
+            $this->typoScriptConfiguration->getObjectByPathOrDefault('plugin.tx_meilisearch.settings.', [])
+        );
+    }
+
+    /**
+     * Initialize the Solr connection and
+     * test the connection through a ping
+     */
+    protected function initializeSearch()
+    {
+        /** @var \WapplerSystems\Meilisearch\ConnectionManager $solrConnection */
+        try {
+            $solrConnection = $this->objectManager->get(ConnectionManager::class)->getConnectionByPageId($this->typoScriptFrontendController->id, Util::getLanguageUid(), $this->typoScriptFrontendController->MP);
+            $search = $this->objectManager->get(Search::class, $solrConnection);
+
+            $this->searchService = $this->objectManager->get(
+                SearchResultSetService::class,
+                /** @scrutinizer ignore-type */ $this->typoScriptConfiguration,
+                /** @scrutinizer ignore-type */ $search
+            );
+        } catch (NoSolrConnectionFoundException $e) {
+            $this->handleSolrUnavailable();
+        }
+    }
+
+    /**
+     * @return SearchRequestBuilder
+     */
+    protected function getSearchRequestBuilder()
+    {
+        if ($this->searchRequestBuilder === null) {
+            $this->searchRequestBuilder = GeneralUtility::makeInstance(SearchRequestBuilder::class, /** @scrutinizer ignore-type */ $this->typoScriptConfiguration);
+        }
+
+        return $this->searchRequestBuilder;
+    }
+
+    /**
+     * Called when the solr server is unavailable.
+     *
+     * @return void
+     */
+    protected function handleSolrUnavailable()
+    {
+        if ($this->typoScriptConfiguration->getLoggingExceptions()) {
+            /** @var SolrLogManager $logger */
+            $logger = GeneralUtility::makeInstance(SolrLogManager::class, /** @scrutinizer ignore-type */ __CLASS__);
+            $logger->log(SolrLogManager::ERROR, 'Solr server is not available');
+        }
+    }
+
+    /**
+     * Emits signal for various actions
+     *
+     * @param string $className Name of the class containing the signal
+     * @param string $signalName Name of the signal slot
+     * @param array $signalArguments arguments for the signal slot
+     *
+     * @return array
+     */
+    protected function emitActionSignal($className, $signalName, array $signalArguments)
+    {
+        return $this->signalSlotDispatcher->dispatch($className, $signalName, $signalArguments)[0];
+    }
+}

Classes/Controller/Backend/PageModuleSummary.php

@@ -0,0 +1,214 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Controller\Backend;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2012-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Reflection\ObjectAccess;
+use TYPO3\CMS\Fluid\View\StandaloneView;
+use TYPO3\CMS\Core\Localization\LanguageService;
+use TYPO3\CMS\Backend\View\PageLayoutView;
+
+/**
+ * Summary to display flexform settings in the page layout backend module.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class PageModuleSummary
+{
+    /**
+     * PageLayoutView
+     *
+     * @var PageLayoutView
+     */
+    protected $pageLayoutView;
+
+    /**
+     * @var array
+     */
+    protected $pluginContentElement = [];
+
+    /**
+     * @var array
+     */
+    protected $flexformData = [];
+
+    /**
+     * @var array
+     */
+    protected $settings = [];
+
+    /**
+     * Returns information about a plugin's flexform configuration
+     *
+     * @param array $parameters Parameters to the hook
+     * @return string Plugin configuration information
+     */
+    public function getSummary(array $parameters)
+    {
+        $this->initialize($parameters['row'], $parameters['pObj']);
+
+        $this->addTargetPage();
+        $this->addSettingFromFlexForm('Filter', 'search.query.filter');
+        $this->addSettingFromFlexForm('Sorting', 'search.query.sortBy');
+        $this->addSettingFromFlexForm('Results per Page', 'search.results.resultsPerPage');
+        $this->addSettingFromFlexForm('Boost Function', 'search.query.boostFunction');
+        $this->addSettingFromFlexForm('Boost Query', 'search.query.boostQuery');
+        $this->addSettingFromFlexForm('Tie Breaker', 'search.query.tieParameter');
+        $this->addSettingFromFlexForm('Template', 'view.templateFiles.results');
+        return $this->render();
+    }
+
+    /**
+     * @param array $contentElement
+     * @param PageLayoutView $pObj
+     */
+    protected function initialize(array $contentElement, PageLayoutView $pObj)
+    {
+        $this->pageLayoutView = $pObj;
+
+        /** @var $service \TYPO3\CMS\Core\Service\FlexFormService::class */
+        $service = GeneralUtility::makeInstance(\TYPO3\CMS\Core\Service\FlexFormService::class);
+        $this->flexformData = $service->convertFlexFormContentToArray($contentElement['pi_flexform']);
+        $this->pluginContentElement = $contentElement;
+    }
+
+    /**
+     * Adds the target page to the settings.
+     */
+    protected function addTargetPage()
+    {
+        $targetPageId = $this->getFieldFromFlexform('search.targetPage');
+        if (!empty($targetPageId)) {
+            $page = BackendUtility::getRecord('pages', $targetPageId, 'title');
+            $this->settings['Target Page'] = '[' . (int)$targetPageId . '] ' . $page['title'];
+        }
+    }
+
+    /**
+     * @param string $settingName
+     * @param string $flexFormField
+     */
+    protected function addSettingFromFlexForm($settingName, $flexFormField)
+    {
+        $value = $this->getFieldFromFlexform($flexFormField);
+
+        if (is_array($value)) {
+            $value = $this->addSettingFromFlexFormArray($settingName, $value);
+        }
+        $this->addSettingIfNotEmpty($settingName, (string)$value);
+    }
+
+    /**
+     * @param string $settingName
+     * @param array $values
+     * @return bool
+     */
+    protected function addSettingFromFlexFormArray($settingName, $values)
+    {
+        foreach ($values as $item) {
+            if (!isset($item['field'])) {
+                continue;
+            }
+            $field = $item['field'];
+
+            $label = $settingName . ' ';
+            $label .= isset($field['field']) ? $field['field'] : '';
+            $fieldValue = isset($field['value']) ? $field['value'] : '';
+            $this->addSettingIfNotEmpty($label, (string)$fieldValue);
+        }
+    }
+
+    /**
+     * @param string $settingName
+     * @param string $value
+     */
+    protected function addSettingIfNotEmpty($settingName, $value)
+    {
+        if (!empty($value)) {
+            $this->settings[$settingName] = $value;
+        }
+    }
+
+    /**
+     * Gets a field's value from flexform configuration, will check if
+     * flexform configuration is available.
+     *
+     * @param string $path name of the field
+     * @return string if nothing found, value if found
+     */
+    protected function getFieldFromFlexform($path)
+    {
+        return ObjectAccess::getPropertyPath($this->flexformData, $path);
+    }
+
+    /**
+     * @return string
+     */
+    protected function render()
+    {
+        /** @var $standaloneView StandaloneView */
+        $standaloneView = GeneralUtility::makeInstance(StandaloneView::class);
+        $standaloneView->setTemplatePathAndFilename(
+            GeneralUtility::getFileAbsFileName('EXT:meilisearch/Resources/Private/Templates/Backend/PageModule/Summary.html')
+        );
+
+        $standaloneView->assignMultiple([
+            'pluginLabel' => $this->getPluginLabel(),
+            'hidden' => $this->pluginContentElement['hidden'],
+            'settings' => $this->settings,
+        ]);
+        return $standaloneView->render();
+    }
+
+    /**
+     * Returns the plugin label
+     *
+     * @return string
+     */
+    protected function getPluginLabel()
+    {
+        $label = BackendUtility::getLabelFromItemListMerged($this->pluginContentElement['pid'], 'tt_content', 'list_type', $this->pluginContentElement['list_type']);
+        if (!empty($label)) {
+            $label = $this->getLanguageService()->sL($label);
+        } else {
+            $label = sprintf($this->getLanguageService()->sL('LLL:EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.noMatchingValue'), $this->pluginContentElement['list_type']);
+        }
+
+        return $this->pageLayoutView->linkEditContent(htmlspecialchars($label), $this->pluginContentElement);
+    }
+
+    /**
+     * Returns the language service
+     *
+     * @return LanguageService
+     */
+    protected function getLanguageService(): LanguageService
+    {
+        return $GLOBALS['LANG'];
+    }
+}

Classes/Controller/Backend/Search/AbstractModuleController.php

@@ -0,0 +1,328 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller\Backend\Search;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use WapplerSystems\Meilisearch\System\Solr\SolrConnection as SolrCoreConnection;
+use WapplerSystems\Meilisearch\System\Mvc\Backend\Component\Exception\InvalidViewObjectNameException;
+use WapplerSystems\Meilisearch\System\Mvc\Backend\Service\ModuleDataStorageService;
+use TYPO3\CMS\Backend\Template\Components\Menu\Menu;
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Backend\View\BackendTemplateView;
+use TYPO3\CMS\Core\Authentication\BackendUserAuthentication;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
+use TYPO3\CMS\Extbase\Mvc\View\NotFoundView;
+use TYPO3\CMS\Extbase\Mvc\View\ViewInterface;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * Abstract Module
+ *
+ * @property BackendTemplateView $view
+ */
+abstract class AbstractModuleController extends ActionController
+{
+    /**
+     * Backend Template Container
+     *
+     * @var string
+     */
+    protected $defaultViewObjectName = BackendTemplateView::class;
+
+    /**
+     * In the pagetree selected page UID
+     *
+     * @var int
+     */
+    protected $selectedPageUID;
+
+    /**
+     * Holds the requested page UID because the selected page uid,
+     * might be overwritten by the automatic site selection.
+     *
+     * @var int
+     */
+    protected $requestedPageUID;
+
+    /**
+     * @var Site
+     */
+    protected $selectedSite;
+
+    /**
+     * @var SiteRepository
+     */
+    protected $siteRepository;
+
+    /**
+     * @var SolrCoreConnection
+     */
+    protected $selectedSolrCoreConnection;
+
+    /**
+     * @var Menu
+     */
+    protected $coreSelectorMenu = null;
+
+    /**
+     * @var ConnectionManager
+     */
+    protected $solrConnectionManager = null;
+
+    /**
+     * @var ModuleDataStorageService
+     */
+    protected $moduleDataStorageService = null;
+
+    /**
+     * @param Site $selectedSite
+     */
+    public function setSelectedSite(Site $selectedSite)
+    {
+        $this->selectedSite = $selectedSite;
+    }
+
+    /**
+     * @param SiteRepository $siteRepository
+     */
+    public function injectSiteRepository(SiteRepository $siteRepository)
+    {
+        $this->siteRepository = $siteRepository;
+    }
+
+    /**
+     * Initializes the controller and sets needed vars.
+     */
+    protected function initializeAction()
+    {
+        parent::initializeAction();
+        $this->solrConnectionManager = GeneralUtility::makeInstance(ConnectionManager::class);
+        $this->moduleDataStorageService = GeneralUtility::makeInstance(ModuleDataStorageService::class);
+
+        $this->selectedPageUID = (int)GeneralUtility::_GP('id');
+        if ($this->request->hasArgument('id')) {
+            $this->selectedPageUID = (int)$this->request->getArgument('id');
+        }
+
+        $this->requestedPageUID = $this->selectedPageUID;
+
+        if ($this->autoSelectFirstSiteAndRootPageWhenOnlyOneSiteIsAvailable()) {
+            return;
+        }
+
+        if ($this->selectedPageUID < 1) {
+            return;
+        }
+
+        try {
+            $this->selectedSite = $this->siteRepository->getSiteByPageId($this->selectedPageUID);
+        } catch (\InvalidArgumentException $exception) {
+            return;
+        }
+    }
+
+    /**
+     * @return bool
+     * @throws \Exception
+     */
+    protected function autoSelectFirstSiteAndRootPageWhenOnlyOneSiteIsAvailable(): bool
+    {
+        if (count($this->siteRepository->getAvailableSites()) == 1) {
+            $this->selectedSite = $this->siteRepository->getFirstAvailableSite();
+
+            // we only overwrite the selected pageUid when no id was passed
+            if ($this->selectedPageUID === 0) {
+                $this->selectedPageUID = $this->selectedSite->getRootPageId();
+            }
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Set up the doc header properly here
+     *
+     * @param ViewInterface $view
+     * @return void
+     */
+    protected function initializeView(ViewInterface $view)
+    {
+        parent::initializeView($view);
+        $sites = $this->siteRepository->getAvailableSites();
+
+        $selectOtherPage = count($sites) > 0 || $this->selectedPageUID < 1;
+        $this->view->assign('showSelectOtherPage', $selectOtherPage);
+        $this->view->assign('pageUID', $this->selectedPageUID);
+        if ($view instanceof NotFoundView || $this->selectedPageUID < 1) {
+            return;
+        }
+        $this->view->getModuleTemplate()->addJavaScriptCode('mainJsFunctions', '
+                top.fsMod.recentIds["searchbackend"] = ' . (int)$this->selectedPageUID . ';'
+        );
+        if (null === $this->selectedSite) {
+            return;
+        }
+
+        /* @var BackendUserAuthentication $beUser */
+        $beUser = $GLOBALS['BE_USER'];
+        $permissionClause = $beUser->getPagePermsClause(1);
+        $pageRecord = BackendUtility::readPageAccess($this->selectedSite->getRootPageId(), $permissionClause);
+
+        if (false === $pageRecord) {
+            throw new \InvalidArgumentException(vsprintf('There is something wrong with permissions for page "%s" for backend user "%s".', [$this->selectedSite->getRootPageId(), $beUser->user['username']]), 1496146317);
+        }
+        $this->view->getModuleTemplate()->getDocHeaderComponent()->setMetaInformation($pageRecord);
+    }
+
+    /**
+     * Generates selector menu in backends doc header using selected page from page tree.
+     *
+     * @param string|null $uriToRedirectTo
+     */
+    public function generateCoreSelectorMenuUsingPageTree(string $uriToRedirectTo = null)
+    {
+        if ($this->selectedPageUID < 1 || null === $this->selectedSite) {
+            return;
+        }
+
+        if ($this->view instanceof NotFoundView) {
+            $this->initializeSelectedSolrCoreConnection();
+            return;
+        }
+
+        $this->generateCoreSelectorMenu($this->selectedSite, $uriToRedirectTo);
+    }
+
+    /**
+     * Generates Core selector Menu for given Site.
+     *
+     * @param Site $site
+     * @param string|null $uriToRedirectTo
+     * @throws InvalidViewObjectNameException
+     */
+    protected function generateCoreSelectorMenu(Site $site, string $uriToRedirectTo = null)
+    {
+        if (!$this->view instanceof BackendTemplateView) {
+            throw new InvalidViewObjectNameException(vsprintf(
+                'The controller "%s" must use BackendTemplateView to be able to generate menu for backends docheader. \
+                Please set `protected $defaultViewObjectName = BackendTemplateView::class;` field in your controller.',
+                [static::class]), 1493804179);
+        }
+        $this->view->getModuleTemplate()->setFlashMessageQueue($this->controllerContext->getFlashMessageQueue());
+
+        $this->coreSelectorMenu = $this->view->getModuleTemplate()->getDocHeaderComponent()->getMenuRegistry()->makeMenu();
+        $this->coreSelectorMenu->setIdentifier('component_core_selector_menu');
+
+        if (!isset($uriToRedirectTo)) {
+            $uriToRedirectTo = $this->uriBuilder->reset()->uriFor();
+        }
+
+        $this->initializeSelectedSolrCoreConnection();
+        $cores = $this->solrConnectionManager->getConnectionsBySite($site);
+        foreach ($cores as $core) {
+            $coreAdmin = $core->getAdminService();
+            $menuItem = $this->coreSelectorMenu->makeMenuItem();
+            $menuItem->setTitle($coreAdmin->getCorePath());
+            $uri = $this->uriBuilder->reset()->uriFor('switchCore',
+                [
+                    'corePath' => $coreAdmin->getCorePath(),
+                    'uriToRedirectTo' => $uriToRedirectTo
+                ]
+            );
+            $menuItem->setHref($uri);
+
+            if ($coreAdmin->getCorePath() == $this->selectedSolrCoreConnection->getAdminService()->getCorePath()) {
+                $menuItem->setActive(true);
+            }
+            $this->coreSelectorMenu->addMenuItem($menuItem);
+        }
+
+        $this->view->getModuleTemplate()->getDocHeaderComponent()->getMenuRegistry()->addMenu($this->coreSelectorMenu);
+    }
+
+    /**
+     * Switches used core.
+     *
+     * Note: Does not check availability of core in site. All this stuff is done in the generation step.
+     *
+     * @param string $corePath
+     * @param string $uriToRedirectTo
+     */
+    public function switchCoreAction(string $corePath, string $uriToRedirectTo)
+    {
+        $moduleData = $this->moduleDataStorageService->loadModuleData();
+        $moduleData->setCore($corePath);
+
+        $this->moduleDataStorageService->persistModuleData($moduleData);
+        $message = LocalizationUtility::translate('coreselector_switched_successfully', 'solr', [$corePath]);
+        $this->addFlashMessage($message);
+        $this->redirectToUri($uriToRedirectTo);
+    }
+
+    /**
+     * Initializes the solr core connection considerately to the components state.
+     * Uses and persists default core connection if persisted core in Site does not exist.
+     *
+     */
+    private function initializeSelectedSolrCoreConnection()
+    {
+        $moduleData = $this->moduleDataStorageService->loadModuleData();
+
+        $solrCoreConnections = $this->solrConnectionManager->getConnectionsBySite($this->selectedSite);
+        $currentSolrCorePath = $moduleData->getCore();
+        if (empty($currentSolrCorePath)) {
+            $this->initializeFirstAvailableSolrCoreConnection($solrCoreConnections, $moduleData);
+            return;
+        }
+        foreach ($solrCoreConnections as $solrCoreConnection) {
+            if ($solrCoreConnection->getAdminService()->getCorePath() == $currentSolrCorePath) {
+                $this->selectedSolrCoreConnection = $solrCoreConnection;
+            }
+        }
+        if (!$this->selectedSolrCoreConnection instanceof SolrCoreConnection && count($solrCoreConnections) > 0) {
+            $this->initializeFirstAvailableSolrCoreConnection($solrCoreConnections, $moduleData);
+            $message = LocalizationUtility::translate('coreselector_switched_to_default_core', 'solr', [$currentSolrCorePath, $this->selectedSite->getLabel(), $this->selectedSolrCoreConnection->getAdminService()->getCorePath()]);
+            $this->addFlashMessage($message, '', AbstractMessage::NOTICE);
+        }
+    }
+
+    /**
+     * @param SolrCoreConnection[] $solrCoreConnections
+     */
+    private function initializeFirstAvailableSolrCoreConnection(array $solrCoreConnections, $moduleData)
+    {
+        if (empty($solrCoreConnections)) {
+            return;
+        }
+        $this->selectedSolrCoreConnection = $solrCoreConnections[0];
+        $moduleData->setCore($this->selectedSolrCoreConnection->getAdminService()->getCorePath());
+        $this->moduleDataStorageService->persistModuleData($moduleData);
+    }
+}

Classes/Controller/Backend/Search/CoreOptimizationModuleController.php

@@ -0,0 +1,386 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller\Backend\Search;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solrs-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Utility\ManagedResourcesUtility;
+use TYPO3\CMS\Backend\Template\ModuleTemplate;
+use TYPO3\CMS\Core\Messaging\FlashMessage;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\View\ViewInterface;
+
+/**
+ * Manage Synonyms and Stop words in Backend Module
+ * @property \TYPO3\CMS\Extbase\Mvc\Web\Response $response
+ */
+class CoreOptimizationModuleController extends AbstractModuleController
+{
+    /**
+     * Set up the doc header properly here
+     *
+     * @param ViewInterface $view
+     * @return void
+     */
+    protected function initializeView(ViewInterface $view)
+    {
+        parent::initializeView($view);
+
+        $this->generateCoreSelectorMenuUsingPageTree();
+        /* @var ModuleTemplate $module */ // holds the state of chosen tab
+        $module = $this->objectManager->get(ModuleTemplate::class);
+        $coreOptimizationTabs = $module->getDynamicTabMenu([], 'coreOptimization');
+        $this->view->assign('tabs', $coreOptimizationTabs);
+    }
+
+    /**
+     * Gets synonyms and stopwords for the currently selected core
+     *
+     * @return void
+     */
+    public function indexAction()
+    {
+        if ($this->selectedSolrCoreConnection === null) {
+            $this->view->assign('can_not_proceed', true);
+            return;
+        }
+
+        $synonyms = [];
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $rawSynonyms = $coreAdmin->getSynonyms();
+        foreach ($rawSynonyms as $baseWord => $synonymList) {
+            $synonyms[$baseWord] = implode(', ', $synonymList);
+        }
+
+        $stopWords = $coreAdmin->getStopWords();
+        $this->view->assignMultiple([
+            'synonyms' => $synonyms,
+            'stopWords' => implode(PHP_EOL, $stopWords),
+            'stopWordsCount' => count($stopWords)
+        ]);
+    }
+
+    /**
+     * Add synonyms to selected core
+     *
+     * @param string $baseWord
+     * @param string $synonyms
+     * @param bool $overrideExisting
+     * @return void
+     */
+    public function addSynonymsAction(string $baseWord, string $synonyms, $overrideExisting)
+    {
+        if (empty($baseWord) || empty($synonyms)) {
+            $this->addFlashMessage(
+                'Please provide a base word and synonyms.',
+                'Missing parameter',
+                FlashMessage::ERROR
+            );
+        } else {
+            $baseWord = mb_strtolower($baseWord);
+            $synonyms = mb_strtolower($synonyms);
+
+            $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+            if ($overrideExisting && $coreAdmin->getSynonyms($baseWord)) {
+                $coreAdmin->deleteSynonym($baseWord);
+            }
+            $coreAdmin->addSynonym($baseWord, GeneralUtility::trimExplode(',', $synonyms, true));
+            $coreAdmin->reloadCore();
+
+            $this->addFlashMessage(
+                '"' . $synonyms . '" added as synonyms for base word "' . $baseWord . '"'
+            );
+        }
+
+        $this->redirect('index');
+    }
+
+    /**
+     * @param string $fileFormat
+     * @return void
+     */
+    public function exportStopWordsAction($fileFormat = 'txt')
+    {
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $this->exportFile(
+            implode(PHP_EOL, $coreAdmin->getStopWords()),
+            'stopwords',
+            $fileFormat
+        );
+    }
+
+    /**
+     * Exports synonyms to a download file.
+     *
+     * @param string $fileFormat
+     * @return string
+     */
+    public function exportSynonymsAction($fileFormat = 'txt')
+    {
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $synonyms = $coreAdmin->getSynonyms();
+        return $this->exportFile(ManagedResourcesUtility::exportSynonymsToTxt($synonyms), 'synonyms', $fileFormat);
+    }
+
+    /**
+     * @param array $synonymFileUpload
+     * @param bool $overrideExisting
+     * @param bool $deleteSynonymsBefore
+     * @return void
+     */
+    public function importSynonymListAction(array $synonymFileUpload, $overrideExisting, $deleteSynonymsBefore)
+    {
+        if ($deleteSynonymsBefore) {
+            $this->deleteAllSynonyms();
+        }
+
+        $fileLines = ManagedResourcesUtility::importSynonymsFromPlainTextContents($synonymFileUpload);
+        $synonymCount = 0;
+
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        foreach ($fileLines as $baseWord => $synonyms) {
+            if (!isset($baseWord) || empty($synonyms)) {
+                continue;
+            }
+            $this->deleteExistingSynonym($overrideExisting, $deleteSynonymsBefore, $baseWord);
+            $coreAdmin->addSynonym($baseWord, $synonyms);
+            $synonymCount++;
+        }
+
+        $coreAdmin->reloadCore();
+        $this->addFlashMessage(
+            $synonymCount . ' synonyms imported.'
+        );
+        $this->redirect('index');
+
+    }
+
+    /**
+     * @param array $stopwordsFileUpload
+     * @param bool $replaceStopwords
+     * @return void
+     */
+    public function importStopWordListAction(array $stopwordsFileUpload, $replaceStopwords)
+    {
+        $this->saveStopWordsAction(
+            ManagedResourcesUtility::importStopwordsFromPlainTextContents($stopwordsFileUpload),
+            $replaceStopwords
+        );
+    }
+
+    /**
+     * Delete complete synonym list
+     *
+     * @return void
+     */
+    public function deleteAllSynonymsAction()
+    {
+        $allSynonymsCouldBeDeleted = $this->deleteAllSynonyms();
+
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $reloadResponse = $coreAdmin->reloadCore();
+
+        if ($allSynonymsCouldBeDeleted
+            && $reloadResponse->getHttpStatus() == 200
+        ) {
+            $this->addFlashMessage(
+                'All synonym removed.'
+            );
+        } else {
+            $this->addFlashMessage(
+                'Failed to remove all synonyms.',
+                'An error occurred',
+                FlashMessage::ERROR
+            );
+        }
+        $this->redirect('index');
+    }
+
+    /**
+     * Deletes a synonym mapping by its base word.
+     *
+     * @param string $baseWord Synonym mapping base word
+     */
+    public function deleteSynonymsAction($baseWord)
+    {
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $deleteResponse = $coreAdmin->deleteSynonym($baseWord);
+        $reloadResponse = $coreAdmin->reloadCore();
+
+        if ($deleteResponse->getHttpStatus() == 200
+            && $reloadResponse->getHttpStatus() == 200
+        ) {
+            $this->addFlashMessage(
+                'Synonym removed.'
+            );
+        } else {
+            $this->addFlashMessage(
+                'Failed to remove synonym.',
+                'An error occurred',
+                FlashMessage::ERROR
+            );
+        }
+
+        $this->redirect('index');
+    }
+
+    /**
+     * Saves the edited stop word list to Solr
+     *
+     * @param string $stopWords
+     * @param bool $replaceStopwords
+     * @return void
+     */
+    public function saveStopWordsAction(string $stopWords, $replaceStopwords = true)
+    {
+        // lowercase stopword before saving because terms get lowercased before stopword filtering
+        $newStopWords = mb_strtolower($stopWords);
+        $newStopWords = GeneralUtility::trimExplode("\n", $newStopWords, true);
+
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $oldStopWords = $coreAdmin->getStopWords();
+
+        if ($replaceStopwords) {
+            $removedStopWords = array_diff($oldStopWords, $newStopWords);
+            $wordsRemoved = $this->removeStopsWordsFromIndex($removedStopWords);
+        } else {
+            $wordsRemoved = true;
+        }
+
+        $wordsAdded = true;
+        $addedStopWords = array_diff($newStopWords, $oldStopWords);
+        if (!empty($addedStopWords)) {
+            $wordsAddedResponse = $coreAdmin->addStopWords($addedStopWords);
+            $wordsAdded = ($wordsAddedResponse->getHttpStatus() == 200);
+        }
+
+        $reloadResponse = $coreAdmin->reloadCore();
+        if ($wordsRemoved && $wordsAdded && $reloadResponse->getHttpStatus() == 200) {
+            $this->addFlashMessage(
+                'Stop Words Updated.'
+            );
+        }
+
+        $this->redirect('index');
+    }
+
+    /**
+     * @param string $content
+     * @param string $type
+     * @param string $fileExtension
+     * @return string
+     */
+    protected function exportFile($content, $type = 'synonyms', $fileExtension = 'txt') : string
+    {
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+
+        $this->response->setHeader('Content-type', 'text/plain', true);
+        $this->response->setHeader('Cache-control', 'public', true);
+        $this->response->setHeader('Content-Description', 'File transfer', true);
+        $this->response->setHeader(
+            'Content-disposition',
+            'attachment; filename =' . $type . '_' .
+            $coreAdmin->getPrimaryEndpoint()->getCore() . '.' . $fileExtension,
+            true
+        );
+
+        $this->response->setContent($content);
+        $this->sendFileResponse();
+    }
+
+    /**
+     * This method send the headers and content and does an exit, since without the exit TYPO3 produces and error.
+     * @return void
+     */
+    protected function sendFileResponse()
+    {
+        $this->response->sendHeaders();
+        $this->response->send();
+        $this->response->shutdown();
+
+        exit();
+    }
+
+    /**
+     * Delete complete synonym list form solr
+     *
+     * @return bool
+     */
+    protected function deleteAllSynonyms() : bool
+    {
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+        $synonyms = $coreAdmin->getSynonyms();
+        $allSynonymsCouldBeDeleted = true;
+
+        foreach ($synonyms as $baseWord => $synonym) {
+            $deleteResponse = $coreAdmin->deleteSynonym($baseWord);
+            $allSynonymsCouldBeDeleted = $allSynonymsCouldBeDeleted && $deleteResponse->getHttpStatus() == 200;
+        }
+
+        return $allSynonymsCouldBeDeleted;
+    }
+
+    /**
+     * @param $stopwordsToRemove
+     * @return bool
+     */
+    protected function removeStopsWordsFromIndex($stopwordsToRemove) : bool
+    {
+        $wordsRemoved = true;
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+
+        foreach ($stopwordsToRemove as $word) {
+            $response = $coreAdmin->deleteStopWord($word);
+            if ($response->getHttpStatus() != 200) {
+                $wordsRemoved = false;
+                $this->addFlashMessage(
+                    'Failed to remove stop word "' . $word . '".',
+                    'An error occurred',
+                    FlashMessage::ERROR
+                );
+                break;
+            }
+        }
+
+        return $wordsRemoved;
+    }
+
+    /**
+     * Delete synonym entry if selceted before
+     * @param bool $overrideExisting
+     * @param bool $deleteSynonymsBefore
+     * @param string $baseWord
+     */
+    protected function deleteExistingSynonym($overrideExisting, $deleteSynonymsBefore, $baseWord)
+    {
+        $coreAdmin = $this->selectedSolrCoreConnection->getAdminService();
+
+        if (!$deleteSynonymsBefore &&
+            $overrideExisting &&
+            $coreAdmin->getSynonyms($baseWord)
+        ) {
+            $coreAdmin->deleteSynonym($baseWord);
+        }
+
+    }
+}

Classes/Controller/Backend/Search/IndexAdministrationModuleController.php

@@ -0,0 +1,195 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller\Backend\Search;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2013-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\IndexQueue\Queue;
+use WapplerSystems\Meilisearch\System\Solr\SolrConnection;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Backend\Routing\UriBuilder as BackendUriBuilder;
+use TYPO3\CMS\Core\Messaging\FlashMessage;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\Web\ReferringRequest;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * Index Administration Module
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class IndexAdministrationModuleController extends AbstractModuleController
+{
+
+    /**
+     * @var Queue
+     */
+    protected $indexQueue;
+
+    /**
+     * @var ConnectionManager
+     */
+    protected $solrConnectionManager = null;
+
+    /**
+     * @param ConnectionManager $solrConnectionManager
+     */
+    public function setSolrConnectionManager(ConnectionManager $solrConnectionManager)
+    {
+        $this->solrConnectionManager = $solrConnectionManager;
+    }
+
+    /**
+     * Initializes the controller before invoking an action method.
+     */
+    protected function initializeAction()
+    {
+        parent::initializeAction();
+        $this->indexQueue = GeneralUtility::makeInstance(Queue::class);
+        $this->solrConnectionManager = GeneralUtility::makeInstance(ConnectionManager::class);
+    }
+
+    /**
+     * Index action, shows an overview of available index maintenance operations.
+     *
+     * @return void
+     */
+    public function indexAction()
+    {
+        if ($this->selectedSite === null || empty($this->solrConnectionManager->getConnectionsBySite($this->selectedSite))) {
+            $this->view->assign('can_not_proceed', true);
+        }
+    }
+
+    /**
+     * Empties the site's indexes.
+     *
+     * @return void
+     */
+    public function emptyIndexAction()
+    {
+        $siteHash = $this->selectedSite->getSiteHash();
+
+        try {
+            $affectedCores = [];
+            $solrServers = $this->solrConnectionManager->getConnectionsBySite($this->selectedSite);
+            foreach ($solrServers as $solrServer) {
+                $writeService = $solrServer->getWriteService();
+                /* @var $solrServer SolrConnection */
+                $writeService->deleteByQuery('siteHash:' . $siteHash);
+                $writeService->commit(false, false, false);
+                $affectedCores[] = $writeService->getPrimaryEndpoint()->getCore();
+            }
+            $message = LocalizationUtility::translate('solr.backend.index_administration.index_emptied_all', 'Solr', [$this->selectedSite->getLabel(), implode(', ', $affectedCores)]);
+            $this->addFlashMessage($message);
+        } catch (\Exception $e) {
+            $this->addFlashMessage(LocalizationUtility::translate('solr.backend.index_administration.error.on_empty_index', 'Solr', [$e->__toString()]), '', FlashMessage::ERROR);
+        }
+
+        $this->redirect('index');
+    }
+
+    /**
+     * Empties the Index Queue
+     *
+     * @return void
+     */
+    public function clearIndexQueueAction()
+    {
+        $this->indexQueue->deleteItemsBySite($this->selectedSite);
+        $this->addFlashMessage(
+            LocalizationUtility::translate('solr.backend.index_administration.success.queue_emptied', 'Solr',
+                [$this->selectedSite->getLabel()])
+        );
+        $this->redirectToReferrerModule();
+    }
+
+    /**
+     * Reloads the site's Solr cores.
+     *
+     * @return void
+     */
+    public function reloadIndexConfigurationAction()
+    {
+        $coresReloaded = true;
+        $reloadedCores = [];
+        $solrServers = $this->solrConnectionManager->getConnectionsBySite($this->selectedSite);
+
+        foreach ($solrServers as $solrServer) {
+            /* @var $solrServer SolrConnection */
+            $coreAdmin = $solrServer->getAdminService();
+            $coreReloaded = $coreAdmin->reloadCore()->getHttpStatus() === 200;
+
+            $coreName = $coreAdmin->getPrimaryEndpoint()->getCore();
+            if (!$coreReloaded) {
+                $coresReloaded = false;
+
+                $this->addFlashMessage(
+                    'Failed to reload index configuration for core "' . $coreName . '"',
+                    '',
+                    FlashMessage::ERROR
+                );
+                break;
+            }
+
+            $reloadedCores[] = $coreName;
+        }
+
+        if ($coresReloaded) {
+            $this->addFlashMessage(
+                'Core configuration reloaded (' . implode(', ', $reloadedCores) . ').',
+                '',
+                FlashMessage::OK
+            );
+        }
+
+        $this->redirect('index');
+    }
+
+    /**
+     * Redirects to the referrer module index Action.
+     *
+     * Fluids <f:form VH can not make urls to other modules properly.
+     * The module name/key is not provided in the hidden fields __referrer by bulding form.
+     * So this is currently the single way to make it possible.
+     *
+     * @todo: remove this method if f:form works properly between backend modules.
+     */
+    protected function redirectToReferrerModule()
+    {
+        $wasFromQueue = $this->request->hasArgument('fromQueue');
+        if (!$wasFromQueue) {
+            $this->redirect('index');
+            return;
+        }
+
+        /* @var BackendUriBuilder $backendUriBuilder */
+        $backendUriBuilder = GeneralUtility::makeInstance(BackendUriBuilder::class);
+
+        $parameters =  ['id' => $this->selectedPageUID];
+        $referringUri = $backendUriBuilder->buildUriFromRoute('searchbackend_SolrIndexqueue', $parameters);
+
+        $this->redirectToUri($referringUri);
+    }
+}

Classes/Controller/Backend/Search/IndexQueueModuleController.php

@@ -0,0 +1,287 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller\Backend\Search;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2013-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Backend\IndexingConfigurationSelectorField;
+use WapplerSystems\Meilisearch\Domain\Index\IndexService;
+use WapplerSystems\Meilisearch\IndexQueue\Queue;
+use TYPO3\CMS\Backend\View\BackendTemplateView;
+use TYPO3\CMS\Core\Messaging\FlashMessage;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\View\ViewInterface;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * Index Queue Module
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ * @property BackendTemplateView $view
+ */
+class IndexQueueModuleController extends AbstractModuleController
+{
+
+    /**
+     * Module name, used to identify a module f.e. in URL parameters.
+     *
+     * @var string
+     */
+    protected $moduleName = 'IndexQueue';
+
+    /**
+     * Module title, shows up in the module menu.
+     *
+     * @var string
+     */
+    protected $moduleTitle = 'Index Queue';
+
+    /**
+     * @var Queue
+     */
+    protected $indexQueue;
+
+    /**
+     * Initializes the controller before invoking an action method.
+     */
+    protected function initializeAction()
+    {
+        parent::initializeAction();
+        $this->indexQueue = GeneralUtility::makeInstance(Queue::class);
+    }
+
+    /**
+     * @param Queue $indexQueue
+     */
+    public function setIndexQueue(Queue $indexQueue)
+    {
+        $this->indexQueue = $indexQueue;
+    }
+
+    /**
+     * Set up the doc header properly here
+     *
+     * @param ViewInterface $view
+     * @return void
+     */
+    protected function initializeView(ViewInterface $view)
+    {
+        parent::initializeView($view);
+    }
+
+    /**
+     * Lists the available indexing configurations
+     *
+     * @return void
+     */
+    public function indexAction()
+    {
+        if (!$this->canQueueSelectedSite()) {
+            $this->view->assign('can_not_proceed', true);
+            return;
+        }
+
+        $statistics = $this->indexQueue->getStatisticsBySite($this->selectedSite);
+        $this->view->assign('indexQueueInitializationSelector', $this->getIndexQueueInitializationSelector());
+        $this->view->assign('indexqueue_statistics', $statistics);
+        $this->view->assign('indexqueue_errors', $this->indexQueue->getErrorsBySite($this->selectedSite));
+    }
+
+    /**
+     * Checks if selected site can be queued.
+     *
+     * @return bool
+     */
+    protected function canQueueSelectedSite()
+    {
+        if ($this->selectedSite === null || empty($this->solrConnectionManager->getConnectionsBySite($this->selectedSite))) {
+            return false;
+        }
+        $enabledIndexQueueConfigurationNames = $this->selectedSite->getSolrConfiguration()->getEnabledIndexQueueConfigurationNames();
+        if (empty($enabledIndexQueueConfigurationNames)) {
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Renders a field to select which indexing configurations to initialize.
+     *
+     * Uses TCEforms.
+     *
+     * @return string Markup for the select field
+     */
+    protected function getIndexQueueInitializationSelector()
+    {
+        $selector = GeneralUtility::makeInstance(IndexingConfigurationSelectorField::class, /** @scrutinizer ignore-type */ $this->selectedSite);
+        $selector->setFormElementName('tx_meilisearch-index-queue-initialization');
+
+        return $selector->render();
+    }
+
+    /**
+     * Initializes the Index Queue for selected indexing configurations
+     *
+     * @return void
+     */
+    public function initializeIndexQueueAction()
+    {
+        $initializedIndexingConfigurations = [];
+
+        $indexingConfigurationsToInitialize = GeneralUtility::_POST('tx_meilisearch-index-queue-initialization');
+        if ((!empty($indexingConfigurationsToInitialize)) && (is_array($indexingConfigurationsToInitialize))) {
+            // initialize selected indexing configuration
+            $initializedIndexingConfigurations = $this->indexQueue->getInitializationService()->initializeBySiteAndIndexConfigurations($this->selectedSite, $indexingConfigurationsToInitialize);
+        } else {
+            $messageLabel = 'solr.backend.index_queue_module.flashmessage.initialize.no_selection';
+            $titleLabel = 'solr.backend.index_queue_module.flashmessage.not_initialized.title';
+            $this->addFlashMessage(
+                LocalizationUtility::translate($messageLabel, 'Solr'),
+                LocalizationUtility::translate($titleLabel, 'Solr'),
+                FlashMessage::WARNING
+            );
+        }
+        $messagesForConfigurations = [];
+        foreach (array_keys($initializedIndexingConfigurations) as $indexingConfigurationName) {
+            $itemCount = $this->indexQueue->getStatisticsBySite($this->selectedSite, $indexingConfigurationName)->getTotalCount();
+            $messagesForConfigurations[] = $indexingConfigurationName . ' (' . $itemCount . ' records)';
+        }
+
+        if (!empty($initializedIndexingConfigurations)) {
+            $messageLabel = 'solr.backend.index_queue_module.flashmessage.initialize.success';
+            $titleLabel = 'solr.backend.index_queue_module.flashmessage.initialize.title';
+            $this->addFlashMessage(
+                LocalizationUtility::translate($messageLabel, 'Solr', [implode(', ', $messagesForConfigurations)]),
+                LocalizationUtility::translate($titleLabel, 'Solr'),
+                FlashMessage::OK
+            );
+        }
+
+        $this->redirect('index');
+    }
+
+    /**
+     * Removes all errors in the index queue list. So that the items can be indexed again.
+     *
+     * @return void
+     */
+    public function resetLogErrorsAction()
+    {
+        $resetResult = $this->indexQueue->resetAllErrors();
+
+        $label = 'solr.backend.index_queue_module.flashmessage.success.reset_errors';
+        $severity = FlashMessage::OK;
+        if (!$resetResult) {
+            $label = 'solr.backend.index_queue_module.flashmessage.error.reset_errors';
+            $severity = FlashMessage::ERROR;
+        }
+
+        $this->addIndexQueueFlashMessage($label, $severity);
+
+        $this->redirect('index');
+    }
+
+    /**
+     * ReQueues a single item in the indexQueue.
+     *
+     * @param string $type
+     * @param int $uid
+     *
+     * @return void
+     */
+    public function requeueDocumentAction(string $type, int $uid)
+    {
+        $label = 'solr.backend.index_queue_module.flashmessage.error.single_item_not_requeued';
+        $severity = FlashMessage::ERROR;
+
+        $updateCount = $this->indexQueue->updateItem($type, $uid, time());
+        if ($updateCount > 0) {
+            $label = 'solr.backend.index_queue_module.flashmessage.success.single_item_was_requeued';
+            $severity = FlashMessage::OK;
+        }
+
+        $this->addIndexQueueFlashMessage($label, $severity);
+
+        $this->redirect('index');
+    }
+
+    /**
+     * Shows the error message for one queue item.
+     *
+     * @param int $indexQueueItemId
+     * @return void
+     */
+    public function showErrorAction(int $indexQueueItemId)
+    {
+        if (is_null($indexQueueItemId)) {
+            // add a flash message and quit
+            $label = 'solr.backend.index_queue_module.flashmessage.error.no_queue_item_for_queue_error';
+            $severity = FlashMessage::ERROR;
+            $this->addIndexQueueFlashMessage($label, $severity);
+
+            return;
+        }
+
+        $item = $this->indexQueue->getItem($indexQueueItemId);
+        $this->view->assign('indexQueueItem', $item);
+    }
+
+    /**
+     * Indexes a few documents with the index service.
+     * @return void
+     * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+     * @throws \TYPO3\CMS\Extbase\Mvc\Exception\UnsupportedRequestTypeException
+     */
+    public function doIndexingRunAction()
+    {
+        /** @var $indexService \WapplerSystems\Meilisearch\Domain\Index\IndexService */
+        $indexService = GeneralUtility::makeInstance(IndexService::class, /** @scrutinizer ignore-type */ $this->selectedSite);
+        $indexWithoutErrors = $indexService->indexItems(10);
+
+        $label = 'solr.backend.index_queue_module.flashmessage.success.index_manual';
+        $severity = FlashMessage::OK;
+        if (!$indexWithoutErrors) {
+            $label = 'solr.backend.index_queue_module.flashmessage.error.index_manual';
+            $severity = FlashMessage::ERROR;
+        }
+
+        $this->addFlashMessage(
+            LocalizationUtility::translate($label, 'Solr'),
+            LocalizationUtility::translate('solr.backend.index_queue_module.flashmessage.index_manual', 'Solr'),
+            $severity
+        );
+
+        $this->redirect('index');
+    }
+
+    /**
+     * Adds a flash message for the index queue module.
+     *
+     * @param string $label
+     * @param int $severity
+     */
+    protected function addIndexQueueFlashMessage($label, $severity)
+    {
+        $this->addFlashMessage(LocalizationUtility::translate($label, 'Solr'), LocalizationUtility::translate('solr.backend.index_queue_module.flashmessage.title', 'Solr'), $severity);
+    }
+}

Classes/Controller/Backend/Search/InfoModuleController.php

@@ -0,0 +1,324 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller\Backend\Search;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Api;
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\Domain\Search\Statistics\StatisticsRepository;
+use WapplerSystems\Meilisearch\Domain\Search\ApacheSolrDocument\Repository;
+use WapplerSystems\Meilisearch\System\Solr\ResponseAdapter;
+use WapplerSystems\Meilisearch\System\Validator\Path;
+use TYPO3\CMS\Backend\Template\ModuleTemplate;
+use TYPO3\CMS\Core\Authentication\BackendUserAuthentication;
+use TYPO3\CMS\Core\Messaging\FlashMessage;
+use TYPO3\CMS\Core\Registry;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\Exception\StopActionException;
+use TYPO3\CMS\Extbase\Mvc\View\ViewInterface;
+
+/**
+ * Info Module
+ */
+class InfoModuleController extends AbstractModuleController
+{
+    /**
+     * @var ConnectionManager
+     */
+    protected $solrConnectionManager;
+
+    /**
+     * @var Repository
+     */
+    protected $apacheSolrDocumentRepository;
+
+    /**
+     * Initializes the controller before invoking an action method.
+     */
+    protected function initializeAction()
+    {
+        parent::initializeAction();
+        $this->solrConnectionManager = GeneralUtility::makeInstance(ConnectionManager::class);
+        $this->apacheSolrDocumentRepository = GeneralUtility::makeInstance(Repository::class);
+
+    }
+    /**
+     * Set up the doc header properly here
+     *
+     * @param ViewInterface $view
+     * @return void
+     */
+    protected function initializeView(ViewInterface $view)
+    {
+        parent::initializeView($view);
+
+        /* @var ModuleTemplate $module */ // holds the state of chosen tab
+        $module = GeneralUtility::makeInstance(ModuleTemplate::class);
+        $coreOptimizationTabs = $module->getDynamicTabMenu([], 'coreOptimization');
+        $this->view->assign('tabs', $coreOptimizationTabs);
+    }
+
+    /**
+     * Index action, shows an overview of the state of the Solr index
+     *
+     * @return void
+     */
+    public function indexAction()
+    {
+        if ($this->selectedSite === null) {
+            $this->view->assign('can_not_proceed', true);
+            return;
+        }
+
+        $this->collectConnectionInfos();
+        $this->collectStatistics();
+        $this->collectIndexFieldsInfo();
+        $this->collectIndexInspectorInfo();
+    }
+
+    /**
+     * @param string $type
+     * @param int $uid
+     * @param int $pageId
+     * @param int $languageUid
+     * @return void
+     */
+    public function documentsDetailsAction(string $type, int $uid, int $pageId, int $languageUid)
+    {
+        $documents = $this->apacheSolrDocumentRepository->findByTypeAndPidAndUidAndLanguageId($type, $uid, $pageId, $languageUid);
+        $this->view->assign('documents', $documents);
+    }
+
+    /**
+     * Checks whether the configured Solr server can be reached and provides a
+     * flash message according to the result of the check.
+     *
+     * @return void
+     */
+    protected function collectConnectionInfos()
+    {
+        $connectedHosts = [];
+        $missingHosts = [];
+        $invalidPaths = [];
+
+        /* @var Path $path */
+        $path = GeneralUtility::makeInstance(Path::class);
+        $connections = $this->solrConnectionManager->getConnectionsBySite($this->selectedSite);
+
+        if (empty($connections)) {
+            $this->view->assign('can_not_proceed', true);
+            return;
+        }
+
+        foreach ($connections as $connection) {
+            $coreAdmin = $connection->getAdminService();
+            $coreUrl = (string)$coreAdmin;
+
+            if ($coreAdmin->ping()) {
+                $connectedHosts[] = $coreUrl;
+            } else {
+                $missingHosts[] = $coreUrl;
+            }
+
+            if (!$path->isValidSolrPath($coreAdmin->getCorePath())) {
+                $invalidPaths[] = $coreAdmin->getCorePath();
+            }
+        }
+
+        $this->view->assignMultiple([
+            'site' => $this->selectedSite,
+            'apiKey' => Api::getApiKey(),
+            'connectedHosts' => $connectedHosts,
+            'missingHosts' => $missingHosts,
+            'invalidPaths' => $invalidPaths
+        ]);
+    }
+
+    /**
+     * Index action, shows an overview of the state of the Solr index
+     *
+     * @return void
+     */
+    protected function collectStatistics()
+    {
+        // TODO make time frame user adjustable, for now it's last 30 days
+
+        $siteRootPageId = $this->selectedSite->getRootPageId();
+        /* @var StatisticsRepository $statisticsRepository */
+        $statisticsRepository = GeneralUtility::makeInstance(StatisticsRepository::class);
+
+        // @TODO: Do we want Typoscript constants to restrict the results?
+        $this->view->assign(
+            'top_search_phrases',
+            $statisticsRepository->getTopKeyWordsWithHits($siteRootPageId, 30, 5)
+        );
+        $this->view->assign(
+            'top_search_phrases_without_hits',
+            $statisticsRepository->getTopKeyWordsWithoutHits($siteRootPageId, 30, 5)
+        );
+        $this->view->assign(
+            'search_phrases_statistics',
+            $statisticsRepository->getSearchStatistics($siteRootPageId, 30, 100)
+        );
+
+        $labels = [];
+        $data = [];
+        $chartData = $statisticsRepository->getQueriesOverTime($siteRootPageId, 30, 86400);
+        foreach ($chartData as $bucket) {
+            $labels[] = strftime('%x', $bucket['timestamp']);
+            $data[] = (int)$bucket['numQueries'];
+        }
+
+        $this->view->assign('queriesChartLabels', json_encode($labels));
+        $this->view->assign('queriesChartData', json_encode($data));
+    }
+
+    /**
+     * Gets Luke meta data for the currently selected core and provides a list
+     * of that data.
+     *
+     * @return void
+     */
+    protected function collectIndexFieldsInfo()
+    {
+        $indexFieldsInfoByCorePaths = [];
+
+        $solrCoreConnections = $this->solrConnectionManager->getConnectionsBySite($this->selectedSite);
+        foreach ($solrCoreConnections as $solrCoreConnection) {
+            $coreAdmin = $solrCoreConnection->getAdminService();
+
+            $indexFieldsInfo = [
+                'corePath' => $coreAdmin->getCorePath()
+            ];
+            if ($coreAdmin->ping()) {
+                $lukeData = $coreAdmin->getLukeMetaData();
+
+                /* @var Registry $registry */
+                $registry = GeneralUtility::makeInstance(Registry::class);
+                $limit = $registry->get('tx_meilisearch', 'luke.limit', 20000);
+                $limitNote = '';
+
+                if (isset($lukeData->index->numDocs) && $lukeData->index->numDocs > $limit) {
+                    $limitNote = '<em>Too many terms</em>';
+                } elseif (isset($lukeData->index->numDocs)) {
+                    $limitNote = 'Nothing indexed';
+                    // below limit, so we can get more data
+                    // Note: we use 2 since 1 fails on Ubuntu Hardy.
+                    $lukeData = $coreAdmin->getLukeMetaData(2);
+                }
+
+                $fields = $this->getFields($lukeData, $limitNote);
+                $coreMetrics = $this->getCoreMetrics($lukeData, $fields);
+
+                $indexFieldsInfo['noError'] = 'OK';
+                $indexFieldsInfo['fields'] = $fields;
+                $indexFieldsInfo['coreMetrics'] = $coreMetrics;
+            } else {
+                $indexFieldsInfo['noError'] = null;
+
+                $this->addFlashMessage(
+                    '',
+                    'Unable to contact Apache Solr server: ' . $this->selectedSite->getLabel() . ' ' . $coreAdmin->getCorePath(),
+                    FlashMessage::ERROR
+                );
+            }
+            $indexFieldsInfoByCorePaths[$coreAdmin->getCorePath()] = $indexFieldsInfo;
+        }
+        $this->view->assign('indexFieldsInfoByCorePaths', $indexFieldsInfoByCorePaths);
+    }
+
+    /**
+     * Retrieves the information for the index inspector.
+     *
+     * @return void
+     */
+    protected function collectIndexInspectorInfo()
+    {
+        $solrCoreConnections = $this->solrConnectionManager->getConnectionsBySite($this->selectedSite);
+        $documentsByCoreAndType = [];
+        foreach ($solrCoreConnections as $languageId => $solrCoreConnection) {
+            $coreAdmin = $solrCoreConnection->getAdminService();
+            $documents = $this->apacheSolrDocumentRepository->findByPageIdAndByLanguageId($this->selectedPageUID, $languageId);
+
+            $documentsByType = [];
+            foreach ($documents as $document) {
+                $documentsByType[$document['type']][] = $document;
+            }
+
+            $documentsByCoreAndType[$languageId]['core'] = $coreAdmin;
+            $documentsByCoreAndType[$languageId]['documents'] = $documentsByType;
+        }
+
+        $this->view->assignMultiple([
+            'pageId' => $this->selectedPageUID,
+            'indexInspectorDocumentsByLanguageAndType' => $documentsByCoreAndType
+        ]);
+    }
+
+    /**
+     * Gets field metrics.
+     *
+     * @param ResponseAdapter $lukeData Luke index data
+     * @param string $limitNote Note to display if there are too many documents in the index to show number of terms for a field
+     *
+     * @return array An array of field metrics
+     */
+    protected function getFields(ResponseAdapter $lukeData, $limitNote)
+    {
+        $rows = [];
+
+        $fields = (array)$lukeData->fields;
+        foreach ($fields as $name => $field) {
+            $rows[$name] = [
+                'name' => $name,
+                'type' => $field->type,
+                'docs' => isset($field->docs) ? $field->docs : 0,
+                'terms' => isset($field->distinct) ? $field->distinct : $limitNote
+            ];
+        }
+        ksort($rows);
+
+        return $rows;
+    }
+
+    /**
+     * Gets general core metrics.
+     *
+     * @param ResponseAdapter $lukeData Luke index data
+     * @param array $fields Fields metrics
+     *
+     * @return array An array of core metrics
+     */
+    protected function getCoreMetrics(ResponseAdapter $lukeData, array $fields)
+    {
+        $coreMetrics = [
+            'numberOfDocuments' => $lukeData->index->numDocs,
+            'numberOfDeletedDocuments' => $lukeData->index->deletedDocs,
+            'numberOfTerms' => $lukeData->index->numTerms,
+            'numberOfFields' => count($fields)
+        ];
+
+        return $coreMetrics;
+    }
+}

Classes/Controller/SearchController.php

@@ -0,0 +1,210 @@
+<?php
+namespace WapplerSystems\Meilisearch\Controller;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use WapplerSystems\Meilisearch\System\Solr\SolrUnavailableException;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Extbase\Mvc\View\ViewInterface;
+use TYPO3\CMS\Extbase\Mvc\Web\Response;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Fluid\View\TemplateView;
+
+/**
+ * Class SearchController
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class SearchController extends AbstractBaseController
+{
+    /**
+     * @var TemplateView
+     */
+    protected $view;
+
+    /**
+     * Provide search query in extbase arguments.
+     */
+    protected function initializeAction()
+    {
+        parent::initializeAction();
+        $this->mapGlobalQueryStringWhenEnabled();
+    }
+
+    /**
+     * @return void
+     */
+    protected function mapGlobalQueryStringWhenEnabled()
+    {
+        $query = GeneralUtility::_GET('q');
+
+        $useGlobalQueryString = $query !== null && !$this->typoScriptConfiguration->getSearchIgnoreGlobalQParameter();
+
+        if ($useGlobalQueryString) {
+            $this->request->setArgument('q', $query);
+        }
+    }
+
+    /**
+     * @param ViewInterface $view
+     */
+    public function initializeView(ViewInterface $view)
+    {
+        if($view instanceof TemplateView) {
+            $customTemplate = $this->getCustomTemplateFromConfiguration();
+            if($customTemplate === '') {
+                return;
+            }
+
+            if(strpos($customTemplate, 'EXT:') !== false) {
+                $view->setTemplatePathAndFilename($customTemplate);
+            } else {
+                $view->setTemplate($customTemplate);
+            }
+        }
+    }
+
+    /**
+     * @return string
+     */
+    protected function getCustomTemplateFromConfiguration()
+    {
+        $templateKey = str_replace('Action', '', $this->actionMethodName);
+        $customTemplate = $this->typoScriptConfiguration->getViewTemplateByFileKey($templateKey);
+        return $customTemplate;
+    }
+
+    /**
+     * Results
+     */
+    public function resultsAction()
+    {
+        try {
+            $arguments = (array)$this->request->getArguments();
+            $pageId = $this->typoScriptFrontendController->getRequestedId();
+            $languageId = Util::getLanguageUid();
+            $searchRequest = $this->getSearchRequestBuilder()->buildForSearch($arguments, $pageId, $languageId);
+
+            $searchResultSet = $this->searchService->search($searchRequest);
+
+            // we pass the search result set to the controller context, to have the possibility
+            // to access it without passing it from partial to partial
+            $this->controllerContext->setSearchResultSet($searchResultSet);
+
+            $values = [
+                'additionalFilters' => $this->getAdditionalFilters(),
+                'resultSet' => $searchResultSet,
+                'pluginNamespace' => $this->typoScriptConfiguration->getSearchPluginNamespace(),
+                'arguments' => $arguments
+            ];
+
+            $values = $this->emitActionSignal(__CLASS__, __FUNCTION__, [$values]);
+
+            $this->view->assignMultiple($values);
+        } catch (SolrUnavailableException $e) {
+            $this->handleSolrUnavailable();
+        }
+    }
+
+    /**
+     * Form
+     */
+    public function formAction()
+    {
+
+        $values = [
+            'search' => $this->searchService->getSearch(),
+            'additionalFilters' => $this->getAdditionalFilters(),
+            'pluginNamespace' => $this->typoScriptConfiguration->getSearchPluginNamespace()
+        ];
+        $values = $this->emitActionSignal(__CLASS__, __FUNCTION__, [$values]);
+
+        $this->view->assignMultiple($values);
+    }
+
+    /**
+     * Frequently Searched
+     */
+    public function frequentlySearchedAction()
+    {
+        /** @var  $searchResultSet SearchResultSet */
+        $searchResultSet = GeneralUtility::makeInstance(SearchResultSet::class);
+
+        $pageId = $this->typoScriptFrontendController->getRequestedId();
+        $languageId = Util::getLanguageUid();
+        $searchRequest = $this->getSearchRequestBuilder()->buildForFrequentSearches($pageId, $languageId);
+        $searchResultSet->setUsedSearchRequest($searchRequest);
+
+        $this->controllerContext->setSearchResultSet($searchResultSet);
+
+        $values = [
+            'additionalFilters' => $this->getAdditionalFilters(),
+            'resultSet' => $searchResultSet
+        ];
+        $values = $this->emitActionSignal(__CLASS__, __FUNCTION__, [$values]);
+
+        $this->view->assignMultiple($values);
+    }
+
+    /**
+     * This action allows to render a detailView with data from solr.
+     *
+     * @param string $documentId
+     */
+    public function detailAction($documentId = '')
+    {
+        try {
+            $document = $this->searchService->getDocumentById($documentId);
+            $this->view->assign('document', $document);
+        } catch (SolrUnavailableException $e) {
+            $this->handleSolrUnavailable();
+        }
+    }
+
+    /**
+     * Rendered when no search is available.
+     * @return string
+     */
+    public function solrNotAvailableAction()
+    {
+        if ($this->response instanceof Response) {
+            $this->response->setStatus(503);
+        }
+    }
+
+    /**
+     * Called when the solr server is unavailable.
+     *
+     * @return void
+     */
+    protected function handleSolrUnavailable()
+    {
+        parent::handleSolrUnavailable();
+        $this->forward('solrNotAvailable');
+    }
+
+    /**
+     * This method can be overwritten to add additionalFilters for the autosuggest.
+     * By default the suggest controller will apply the configured filters from the typoscript configuration.
+     *
+     * @return array
+     */
+    protected function getAdditionalFilters()
+    {
+        return [];
+    }
+}

Classes/Controller/SuggestController.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Suggest\SuggestService;
+use WapplerSystems\Meilisearch\System\Solr\SolrUnavailableException;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Class SuggestController
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class SuggestController extends AbstractBaseController
+{
+    /**
+     * This method creates a suggest json response that can be used in a suggest layer.
+     *
+     * @param string $queryString
+     * @param string $callback
+     * @param array $additionalFilters
+     * @return string
+     */
+    public function suggestAction($queryString, $callback = null, $additionalFilters = [])
+    {
+        // Get suggestions
+        $rawQuery = htmlspecialchars(mb_strtolower(trim($queryString)));
+
+        try {
+            /** @var SuggestService $suggestService */
+            $suggestService = GeneralUtility::makeInstance(
+                SuggestService::class,
+                /** @scrutinizer ignore-type */ $this->typoScriptFrontendController,
+                /** @scrutinizer ignore-type */ $this->searchService,
+                /** @scrutinizer ignore-type */ $this->typoScriptConfiguration);
+
+            $additionalFilters = is_array($additionalFilters) ? array_map("htmlspecialchars", $additionalFilters) : [];
+            $pageId = $this->typoScriptFrontendController->getRequestedId();
+            $languageId = Util::getLanguageUid();
+            $arguments = (array)$this->request->getArguments();
+
+            $searchRequest = $this->getSearchRequestBuilder()->buildForSuggest($arguments, $rawQuery, $pageId, $languageId);
+            $result = $suggestService->getSuggestions($searchRequest, $additionalFilters);
+        } catch (SolrUnavailableException $e) {
+            $this->handleSolrUnavailable();
+            $result = ['status' => false];
+        }
+        if ($callback) {
+            return htmlspecialchars($callback) . '(' . json_encode($result) . ')';
+        }
+        else {
+            return json_encode($result);
+        }
+    }
+
+}

Classes/Domain/Index/Classification/Classification.php

@@ -0,0 +1,111 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Index\Classification;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+
+/**
+ * Class Classification
+ */
+class Classification {
+
+    /**
+     * Array of regular expressions
+     *
+     * @var array
+     */
+    protected $matchPatterns = [];
+
+    /**
+     * Array of regular expressions
+     * @var array
+     */
+    protected $unMatchPatterns = [];
+
+    /**
+     * @var string
+     */
+    protected $mappedClass = '';
+
+    /**
+     * Classification constructor.
+     * @param array $matchPatterns
+     * @param array $unMatchPatterns
+     * @param string $mappedClass
+     */
+    public function __construct(array $matchPatterns = [], array $unMatchPatterns = [],string $mappedClass = '')
+    {
+        $this->matchPatterns = $matchPatterns;
+        $this->unMatchPatterns = $unMatchPatterns;
+        $this->mappedClass = $mappedClass;
+    }
+
+    /**
+     * @return array
+     */
+    public function getUnMatchPatterns(): array
+    {
+        return $this->unMatchPatterns;
+    }
+
+    /**
+     * @param array $unMatchPatterns
+     */
+    public function setUnMatchPatterns(array $unMatchPatterns)
+    {
+        $this->unMatchPatterns = $unMatchPatterns;
+    }
+
+    /**
+     * @return array
+     */
+    public function getMatchPatterns(): array
+    {
+        return $this->matchPatterns;
+    }
+
+    /**
+     * @param array $matchPatterns
+     */
+    public function setMatchPatterns(array $matchPatterns)
+    {
+        $this->matchPatterns = $matchPatterns;
+    }
+
+    /**
+     * @return string
+     */
+    public function getMappedClass(): string
+    {
+        return $this->mappedClass;
+    }
+
+    /**
+     * @param string $mappedClass
+     */
+    public function setMappedClass(string $mappedClass)
+    {
+        $this->mappedClass = $mappedClass;
+    }
+}

Classes/Domain/Index/Classification/ClassificationService.php

@@ -0,0 +1,88 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Index\Classification;
+
+    /***************************************************************
+     *  Copyright notice
+     *
+     *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+     *  All rights reserved
+     *
+     *  This script is part of the TYPO3 project. The TYPO3 project is
+     *  free software; you can redistribute it and/or modify
+     *  it under the terms of the GNU General Public License as published by
+     *  the Free Software Foundation; either version 3 of the License, or
+     *  (at your option) any later version.
+     *
+     *  The GNU General Public License can be found at
+     *  http://www.gnu.org/copyleft/gpl.html.
+     *
+     *  This script is distributed in the hope that it will be useful,
+     *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+     *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+     *  GNU General Public License for more details.
+     *
+     *  This copyright notice MUST APPEAR in all copies of the script!
+     ***************************************************************/
+
+/**
+ * Class ClassificationService
+ */
+class ClassificationService {
+
+    /**
+     * @param string $stringToMatch
+     * @param Classification[] $classifications
+     * @return array
+     */
+    public function getMatchingClassNames(string $stringToMatch, $classifications) : array
+    {
+        $matchingClassification = [];
+        foreach ($classifications as $classification) {
+            $matchingClassification = $this->applyMatchPatterns($stringToMatch, $classification, $matchingClassification);
+            $matchingClassification = $this->applyUnMatchPatterns($stringToMatch, $classification, $matchingClassification);
+        }
+
+        return array_values($matchingClassification);
+    }
+
+    /**
+     * @param string $stringToMatch
+     * @param Classification $classification
+     * @param $matchingClassification
+     * @return array
+     */
+    protected function applyMatchPatterns(string $stringToMatch, $classification, $matchingClassification): array
+    {
+        /** @var $classification Classification */
+        foreach ($classification->getMatchPatterns() as $matchPattern) {
+            if (preg_match_all('~' . $matchPattern . '~ims', $stringToMatch) > 0) {
+                $matchingClassification[] = $classification->getMappedClass();
+                // if we found one match, we do not need to check the other patterns
+                break;
+            }
+        }
+        return array_unique($matchingClassification);
+    }
+
+    /**
+     * @param string $stringToMatch
+     * @param Classification $classification
+     * @param $matchingClassification
+     * @param $messages
+     * @return array
+     */
+    protected function applyUnMatchPatterns(string $stringToMatch, $classification, $matchingClassification): array
+    {
+        foreach ($classification->getUnMatchPatterns() as $unMatchPattern) {
+            if (preg_match_all('~' . $unMatchPattern . '~ims', $stringToMatch) > 0) {
+                // if we found one match, we do not need to check the other patterns
+                $position = array_search($classification->getMappedClass(), $matchingClassification);
+                if ($position !== false) {
+                    unset($matchingClassification[$position]);
+                }
+            }
+        }
+
+        return $matchingClassification;
+    }
+}

Classes/Domain/Index/IndexService.php

@@ -0,0 +1,318 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2015-2016 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\IndexQueue\Indexer;
+use WapplerSystems\Meilisearch\IndexQueue\Item;
+use WapplerSystems\Meilisearch\IndexQueue\Queue;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use WapplerSystems\Meilisearch\Task\IndexQueueWorkerTask;
+use Solarium\Exception\HttpException;
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\SignalSlot\Dispatcher;
+
+/**
+ * Service to perform indexing operations
+ *
+ * @author Timo Hund <timo.schmidt@dkd.de>
+ */
+class IndexService
+{
+    /**
+     * @var TypoScriptConfiguration
+     */
+    protected $configuration;
+
+    /**
+     * @var Site
+     */
+    protected $site;
+
+    /**
+     * @var IndexQueueWorkerTask
+     */
+    protected $contextTask;
+
+    /**
+     * @var Queue
+     */
+    protected $indexQueue;
+
+    /**
+     * @var Dispatcher
+     */
+    protected $signalSlotDispatcher;
+
+    /**
+     * @var \WapplerSystems\Meilisearch\System\Logging\SolrLogManager
+     */
+    protected $logger = null;
+
+    /**
+     * IndexService constructor.
+     * @param Site $site
+     * @param Queue|null $queue
+     * @param Dispatcher|null $dispatcher
+     * @param SolrLogManager|null $solrLogManager
+     */
+    public function __construct(Site $site, Queue $queue = null, Dispatcher $dispatcher = null, SolrLogManager $solrLogManager = null)
+    {
+        $this->site = $site;
+        $this->indexQueue = $queue ?? GeneralUtility::makeInstance(Queue::class);
+        $this->signalSlotDispatcher = $dispatcher ?? GeneralUtility::makeInstance(Dispatcher::class);
+        $this->logger = $solrLogManager ?? GeneralUtility::makeInstance(SolrLogManager::class, /** @scrutinizer ignore-type */ __CLASS__);
+    }
+
+    /**
+     * @param \WapplerSystems\Meilisearch\Task\IndexQueueWorkerTask $contextTask
+     */
+    public function setContextTask($contextTask)
+    {
+        $this->contextTask = $contextTask;
+    }
+
+    /**
+     * @return \WapplerSystems\Meilisearch\Task\IndexQueueWorkerTask
+     */
+    public function getContextTask()
+    {
+        return $this->contextTask;
+    }
+
+    /**
+     * Indexes items from the Index Queue.
+     *
+     * @param int $limit
+     * @return bool
+     */
+    public function indexItems($limit)
+    {
+        $errors     = 0;
+        $indexRunId = uniqid();
+        $configurationToUse = $this->site->getSolrConfiguration();
+        $enableCommitsSetting = $configurationToUse->getEnableCommits();
+
+        // get items to index
+        $itemsToIndex = $this->indexQueue->getItemsToIndex($this->site, $limit);
+
+        $this->emitSignal('beforeIndexItems', [$itemsToIndex, $this->getContextTask(), $indexRunId]);
+
+        foreach ($itemsToIndex as $itemToIndex) {
+            try {
+                // try indexing
+                $this->emitSignal('beforeIndexItem', [$itemToIndex, $this->getContextTask(), $indexRunId]);
+                $this->indexItem($itemToIndex, $configurationToUse);
+                $this->emitSignal('afterIndexItem', [$itemToIndex, $this->getContextTask(), $indexRunId]);
+            } catch (\Exception $e) {
+                $errors++;
+                $this->indexQueue->markItemAsFailed($itemToIndex, $e->getCode() . ': ' . $e->__toString());
+                $this->generateIndexingErrorLog($itemToIndex, $e);
+            }
+        }
+
+        $this->emitSignal('afterIndexItems', [$itemsToIndex, $this->getContextTask(), $indexRunId]);
+
+        if ($enableCommitsSetting && count($itemsToIndex) > 0) {
+            $solrServers = GeneralUtility::makeInstance(ConnectionManager::class)->getConnectionsBySite($this->site);
+            foreach ($solrServers as $solrServer) {
+                try {
+                    $solrServer->getWriteService()->commit(false, false, false);
+                } catch (HttpException $e) {
+                    $errors++;
+                }
+            }
+        }
+
+        return ($errors === 0);
+    }
+
+    /**
+     * Generates a message in the error log when an error occured.
+     *
+     * @param Item $itemToIndex
+     * @param \Exception  $e
+     */
+    protected function generateIndexingErrorLog(Item $itemToIndex, \Exception $e)
+    {
+        $message = 'Failed indexing Index Queue item ' . $itemToIndex->getIndexQueueUid();
+        $data = ['code' => $e->getCode(), 'message' => $e->getMessage(), 'trace' => $e->getTraceAsString(), 'item' => (array)$itemToIndex];
+
+        $this->logger->log(
+            SolrLogManager::ERROR,
+            $message,
+            $data
+        );
+    }
+
+    /**
+     * Builds an emits a singal for the IndexService.
+     *
+     * @param string $name
+     * @param array $arguments
+     * @return mixed
+     */
+    protected function emitSignal($name, $arguments)
+    {
+        return $this->signalSlotDispatcher->dispatch(__CLASS__, $name, $arguments);
+    }
+
+    /**
+     * Indexes an item from the Index Queue.
+     *
+     * @param Item $item An index queue item to index
+     * @param TypoScriptConfiguration $configuration
+     * @return bool TRUE if the item was successfully indexed, FALSE otherwise
+     */
+    protected function indexItem(Item $item, TypoScriptConfiguration $configuration)
+    {
+        $indexer = $this->getIndexerByItem($item->getIndexingConfigurationName(), $configuration);
+
+        // Remember original http host value
+        $originalHttpHost = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : null;
+
+        $itemChangedDate = $item->getChanged();
+        $itemChangedDateAfterIndex = 0;
+
+        try {
+            $this->initializeHttpServerEnvironment($item);
+            $itemIndexed = $indexer->index($item);
+
+            // update IQ item so that the IQ can determine what's been indexed already
+            if ($itemIndexed) {
+                $this->indexQueue->updateIndexTimeByItem($item);
+                $itemChangedDateAfterIndex = $item->getChanged();
+            }
+
+            if ($itemChangedDateAfterIndex > $itemChangedDate && $itemChangedDateAfterIndex > time()) {
+                $this->indexQueue->setForcedChangeTimeByItem($item, $itemChangedDateAfterIndex);
+            }
+        } catch (\Exception $e) {
+            $this->restoreOriginalHttpHost($originalHttpHost);
+            throw $e;
+        }
+
+        $this->restoreOriginalHttpHost($originalHttpHost);
+
+        return $itemIndexed;
+    }
+
+    /**
+     * A factory method to get an indexer depending on an item's configuration.
+     *
+     * By default all items are indexed using the default indexer
+     * (WapplerSystems\Meilisearch\IndexQueue\Indexer) coming with EXT:meilisearch. Pages by default are
+     * configured to be indexed through a dedicated indexer
+     * (WapplerSystems\Meilisearch\IndexQueue\PageIndexer). In all other cases a dedicated indexer
+     * can be specified through TypoScript if needed.
+     *
+     * @param string $indexingConfigurationName Indexing configuration name.
+     * @param TypoScriptConfiguration $configuration
+     * @return Indexer
+     */
+    protected function getIndexerByItem($indexingConfigurationName, TypoScriptConfiguration $configuration)
+    {
+        $indexerClass = $configuration->getIndexQueueIndexerByConfigurationName($indexingConfigurationName);
+        $indexerConfiguration = $configuration->getIndexQueueIndexerConfigurationByConfigurationName($indexingConfigurationName);
+
+        $indexer = GeneralUtility::makeInstance($indexerClass, /** @scrutinizer ignore-type */ $indexerConfiguration);
+        if (!($indexer instanceof Indexer)) {
+            throw new \RuntimeException(
+                'The indexer class "' . $indexerClass . '" for indexing configuration "' . $indexingConfigurationName . '" is not a valid indexer. Must be a subclass of WapplerSystems\Meilisearch\IndexQueue\Indexer.',
+                1260463206
+            );
+        }
+
+        return $indexer;
+    }
+
+    /**
+     * Gets the indexing progress.
+     *
+     * @return float Indexing progress as a two decimal precision float. f.e. 44.87
+     */
+    public function getProgress()
+    {
+        return $this->indexQueue->getStatisticsBySite($this->site)->getSuccessPercentage();
+    }
+
+    /**
+     * Returns the amount of failed queue items for the current site.
+     *
+     * @return int
+     */
+    public function getFailCount()
+    {
+        return $this->indexQueue->getStatisticsBySite($this->site)->getFailedCount();
+    }
+
+    /**
+     * Initializes the $_SERVER['HTTP_HOST'] environment variable in CLI
+     * environments dependent on the Index Queue item's root page.
+     *
+     * When the Index Queue Worker task is executed by a cron job there is no
+     * HTTP_HOST since we are in a CLI environment. RealURL needs the host
+     * information to generate a proper URL though. Using the Index Queue item's
+     * root page information we can determine the correct host although being
+     * in a CLI environment.
+     *
+     * @param Item $item Index Queue item to use to determine the host.
+     * @param
+     */
+    protected function initializeHttpServerEnvironment(Item $item)
+    {
+        static $hosts = [];
+        $rootpageId = $item->getRootPageUid();
+        $hostFound = !empty($hosts[$rootpageId]);
+
+        if (!$hostFound) {
+            $hosts[$rootpageId] = $item->getSite()->getDomain();
+        }
+
+        $_SERVER['HTTP_HOST'] = $hosts[$rootpageId];
+
+        // needed since TYPO3 7.5
+        GeneralUtility::flushInternalRuntimeCaches();
+    }
+
+    /**
+     * @param string|null $originalHttpHost
+     */
+    protected function restoreOriginalHttpHost($originalHttpHost)
+    {
+        if (!is_null($originalHttpHost)) {
+            $_SERVER['HTTP_HOST'] = $originalHttpHost;
+        } else {
+            unset($_SERVER['HTTP_HOST']);
+        }
+
+        // needed since TYPO3 7.5
+        GeneralUtility::flushInternalRuntimeCaches();
+    }
+}

Classes/Domain/Index/PageIndexer/Helper/UriBuilder/AbstractUriStrategy.php

@@ -0,0 +1,159 @@
+<?php declare(strict_types = 1);
+
+namespace WapplerSystems\Meilisearch\Domain\Index\PageIndexer\Helper\UriBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2019 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *  A copy is found in the textfile GPL.txt and important notices to the license
+ *  from the author is found in LICENSE.txt distributed with these scripts.
+ *
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\IndexQueue\Item;
+use WapplerSystems\Meilisearch\IndexQueue\PageIndexerDataUrlModifier;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use WapplerSystems\Meilisearch\System\Url\UrlHelper;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Implementations of this class are able to build an indexing url for solr page indexing.
+ */
+abstract class AbstractUriStrategy
+{
+    /**
+     * @var SolrLogManager|null|object
+     */
+    protected $logger;
+
+    /**
+     * AbstractUriStrategy constructor.
+     * @param SolrLogManager|null $logger
+     */
+    public function __construct(SolrLogManager $logger = null)
+    {
+        $this->logger = $logger ?? GeneralUtility::makeInstance(SolrLogManager::class, /** @scrutinizer ignore-type */ __CLASS__);
+    }
+
+    /**
+     * @param UrlHelper $urlHelper
+     * @param array $overrideConfiguration
+     * @return UrlHelper
+     */
+    protected function applyTypoScriptOverridesOnIndexingUrl(UrlHelper $urlHelper, array $overrideConfiguration = []): UrlHelper
+    {
+        // check whether we should use ssl / https
+        if (!empty($overrideConfiguration['scheme'])) {
+            $urlHelper->setScheme($overrideConfiguration['scheme']);
+        }
+
+        // overwriting the host
+        if (!empty($overrideConfiguration['host'])) {
+            $urlHelper->setHost($overrideConfiguration['host']);
+        }
+
+        // overwriting the port
+        if (!empty($overrideConfiguration['port'])) {
+            $urlHelper->setPort($overrideConfiguration['port']);
+        }
+
+        // setting a path if TYPO3 is installed in a sub directory
+        if (!empty($overrideConfiguration['path'])) {
+            $urlHelper->setPath($overrideConfiguration['path']);
+        }
+
+        return $urlHelper;
+    }
+
+    /**
+     * @param Item $item
+     * @param int $language
+     * @param string $mountPointParameter
+     * @param array $options
+     * @return string
+     */
+    public function getPageIndexingUriFromPageItemAndLanguageId(Item $item, int $language = 0, string $mountPointParameter = '', $options = []): string
+    {
+        $pageIndexUri = $this->buildPageIndexingUriFromPageItemAndLanguageId($item, $language, $mountPointParameter);
+        $urlHelper = GeneralUtility::makeInstance(UrlHelper::class, $pageIndexUri);
+        $overrideConfiguration = is_array($options['frontendDataHelper.']) ? $options['frontendDataHelper.'] : [];
+        $urlHelper = $this->applyTypoScriptOverridesOnIndexingUrl($urlHelper, $overrideConfiguration);
+        $dataUrl = $urlHelper->getUrl();
+
+        if (!GeneralUtility::isValidUrl($dataUrl)) {
+            $this->logger->log(
+                SolrLogManager::ERROR,
+                'Could not create a valid URL to get frontend data while trying to index a page.',
+                [
+                    'item' => (array)$item,
+                    'constructed URL' => $dataUrl,
+                    'scheme' => $urlHelper->getScheme(),
+                    'host' => $urlHelper->getHost(),
+                    'path' => $urlHelper->getPath(),
+                    'page ID' => $item->getRecordUid(),
+                    'indexer options' => $options
+                ]
+            );
+
+            throw new \RuntimeException(
+                'Could not create a valid URL to get frontend data while trying to index a page. Created URL: ' . $dataUrl,
+                1311080805
+            );
+        }
+
+
+        return $this->applyDataUrlModifier($item, $language, $dataUrl, $urlHelper);
+    }
+
+    /**
+     * @param Item $item
+     * @param int $language
+     * @param string $mountPointParameter
+     * @return mixed
+     */
+    abstract protected function buildPageIndexingUriFromPageItemAndLanguageId(Item $item, int $language = 0, string $mountPointParameter = '');
+
+    /**
+     * @param Item $item
+     * @param int $language
+     * @param string $dataUrl
+     * @param UrlHelper $urlHelper
+     * @return string
+     */
+    protected function applyDataUrlModifier(Item $item, int $language, $dataUrl, UrlHelper $urlHelper):string
+    {
+        if (empty($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['IndexQueuePageIndexer']['dataUrlModifier'])) {
+            return $dataUrl;
+        }
+
+        $dataUrlModifier = GeneralUtility::makeInstance($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['IndexQueuePageIndexer']['dataUrlModifier']);
+        if (!$dataUrlModifier instanceof PageIndexerDataUrlModifier) {
+            throw new \RuntimeException($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['IndexQueuePageIndexer']['dataUrlModifier'] . ' is not an implementation of WapplerSystems\Meilisearch\IndexQueue\PageIndexerDataUrlModifier', 1290523345);
+        }
+
+        return $dataUrlModifier->modifyDataUrl($dataUrl,
+            [
+                'item' => $item, 'scheme' => $urlHelper->getScheme(), 'host' => $urlHelper->getHost(),
+                'path' => $urlHelper->getPath(), 'pageId' => $item->getRecordUid(), 'language' => $language
+            ]
+        );
+    }
+}

Classes/Domain/Index/PageIndexer/Helper/UriBuilder/TYPO3SiteStrategy.php

@@ -0,0 +1,85 @@
+<?php declare(strict_types = 1);
+
+namespace WapplerSystems\Meilisearch\Domain\Index\PageIndexer\Helper\UriBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2019 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *  A copy is found in the textfile GPL.txt and important notices to the license
+ *  from the author is found in LICENSE.txt distributed with these scripts.
+ *
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\IndexQueue\Item;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use TYPO3\CMS\Core\Exception\SiteNotFoundException;
+use TYPO3\CMS\Core\Routing\InvalidRouteArgumentsException;
+use TYPO3\CMS\Core\Site\SiteFinder;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * This class is used to build the indexing url for a TYPO3 site that is managed with the TYPO3 site management.
+ *
+ * These sites have the pageId and language information encoded in the speaking url.
+ */
+class TYPO3SiteStrategy extends AbstractUriStrategy
+{
+    /**
+     * @var SiteFinder
+     */
+    protected $siteFinder = null;
+
+    /**
+     * TYPO3SiteStrategy constructor.
+     * @param SolrLogManager|null $logger
+     * @param SiteFinder|null $siteFinder
+     */
+    public function __construct(SolrLogManager $logger = null, SiteFinder $siteFinder = null)
+    {
+        parent::__construct($logger);
+        $this->siteFinder = $siteFinder ?? GeneralUtility::makeInstance(SiteFinder::class);
+    }
+
+    /**
+     * @param Item $item
+     * @param int $language
+     * @param string $mountPointParameter
+     * @return string
+     * @throws SiteNotFoundException
+     * @throws InvalidRouteArgumentsException
+     */
+    protected function buildPageIndexingUriFromPageItemAndLanguageId(Item $item, int $language = 0,  string $mountPointParameter = '')
+    {
+        $site = $this->siteFinder->getSiteByPageId((int)$item->getRecordUid());
+        $parameters = [];
+
+        if ($language > 0) {
+            $parameters['_language'] = $language;
+        };
+
+        if ($mountPointParameter !== '') {
+            $parameters['MP'] = $mountPointParameter;
+        }
+
+        $pageIndexUri = (string)$site->getRouter()->generateUri($item->getRecord(), $parameters);
+        return $pageIndexUri;
+    }
+}

Classes/Domain/Index/PageIndexer/Helper/UriStrategyFactory.php

@@ -0,0 +1,61 @@
+<?php declare(strict_types = 1);
+
+namespace WapplerSystems\Meilisearch\Domain\Index\PageIndexer\Helper;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2019 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *  A copy is found in the textfile GPL.txt and important notices to the license
+ *  from the author is found in LICENSE.txt distributed with these scripts.
+ *
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Index\PageIndexer\Helper\UriBuilder\AbstractUriStrategy;
+use WapplerSystems\Meilisearch\Domain\Index\PageIndexer\Helper\UriBuilder\TYPO3SiteStrategy;
+use WapplerSystems\Meilisearch\System\Util\SiteUtility;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * This class is responsible to retrieve an "UriStrategy" the can build uri's for the site where the
+ * passed page belongs to.
+ *
+ * This can be:
+ * * A TYPO3 site managed with site management
+ * * A TYPO3 site without site management where the url is build by EXT:meilisearch with L and id param and information from the domain
+ * record or solr specific configuration.
+ */
+class UriStrategyFactory
+{
+    /**
+     * @param integer $pageId
+     * @oaram array $overrideConfiguration
+     * @return AbstractUriStrategy
+     * @throws \Exception
+     */
+    public function getForPageId(int $pageId): AbstractUriStrategy
+    {
+        if (!SiteUtility::getIsSiteManagedSite($pageId)) {
+            throw new \Exception('Site of page with uid ' . $pageId . ' is not a TYPO3 managed site');
+        }
+
+        return GeneralUtility::makeInstance(TYPO3SiteStrategy::class);
+    }
+}

Classes/Domain/Index/Queue/GarbageRemover/AbstractStrategy.php

@@ -0,0 +1,175 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\GarbageRemover;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2018 - Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\GarbageCollectorPostProcessor;
+use WapplerSystems\Meilisearch\IndexQueue\Queue;
+use WapplerSystems\Meilisearch\System\Solr\SolrConnection;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * An implementation ob a garbage remover strategy is responsible to remove all garbage from the index queue and
+ * the solr server for a certain table and uid combination.
+ */
+abstract class AbstractStrategy
+{
+
+    /**
+     * @var Queue
+     */
+    protected $queue;
+
+    /**
+     * @var ConnectionManager
+     */
+    protected $connectionManager;
+
+    /**
+     * AbstractStrategy constructor.
+     * @param Queue|null $queue
+     * @param ConnectionManager|null $connectionManager
+     */
+    public function __construct(Queue $queue = null, ConnectionManager $connectionManager = null)
+    {
+        $this->queue = $queue ?? GeneralUtility::makeInstance(Queue::class);
+        $this->connectionManager = $connectionManager ?? GeneralUtility::makeInstance(ConnectionManager::class);
+    }
+
+    /**
+     * Call's the removal of the strategy and afterwards the garbagecollector post processing hook.
+     *
+     * @param string $table
+     * @param int $uid
+     * @return mixed
+     */
+    public function removeGarbageOf($table, $uid)
+    {
+        $this->removeGarbageOfByStrategy($table, $uid);
+        $this->callPostProcessGarbageCollectorHook($table, $uid);
+    }
+
+    /**
+     * A implementation of the GarbageCollection strategy is responsible to remove the garbage from
+     * the indexqueue and from the solr server.
+     *
+     * @param string $table
+     * @param int $uid
+     * @return mixed
+     */
+    abstract protected function removeGarbageOfByStrategy($table, $uid);
+
+    /**
+     * Deletes a document from solr and from the index queue.
+     *
+     * @param string $table
+     * @param integer $uid
+     */
+    protected function deleteInSolrAndRemoveFromIndexQueue($table, $uid)
+    {
+        $this->deleteIndexDocuments($table, $uid);
+        $this->queue->deleteItem($table, $uid);
+    }
+
+    /**
+     * Deletes a document from solr and updates the item in the index queue (e.g. on page content updates).
+     *
+     * @param string $table
+     * @param integer $uid
+     */
+    protected function deleteInSolrAndUpdateIndexQueue($table, $uid)
+    {
+        $this->deleteIndexDocuments($table, $uid);
+        $this->queue->updateItem($table, $uid);
+    }
+
+    /**
+     * Deletes index documents for a given record identification.
+     *
+     * @param string $table The record's table name.
+     * @param int $uid The record's uid.
+     */
+    protected function deleteIndexDocuments($table, $uid, $language = 0)
+    {
+        // record can be indexed for multiple sites
+        $indexQueueItems = $this->queue->getItems($table, $uid);
+        foreach ($indexQueueItems as $indexQueueItem) {
+            $site = $indexQueueItem->getSite();
+            $enableCommitsSetting = $site->getSolrConfiguration()->getEnableCommits();
+            $siteHash = $site->getSiteHash();
+            // a site can have multiple connections (cores / languages)
+            $solrConnections = $this->connectionManager->getConnectionsBySite($site);
+            if ($language > 0) {
+                $solrConnections = [$language => $solrConnections[$language]];
+            }
+            $this->deleteRecordInAllSolrConnections($table, $uid, $solrConnections, $siteHash, $enableCommitsSetting);
+        }
+    }
+
+    /**
+     * Deletes the record in all solr connections from that site.
+     *
+     * @param string $table
+     * @param int $uid
+     * @param SolrConnection[] $solrConnections
+     * @param string $siteHash
+     * @param boolean $enableCommitsSetting
+     */
+    protected function deleteRecordInAllSolrConnections($table, $uid, $solrConnections, $siteHash, $enableCommitsSetting)
+    {
+        foreach ($solrConnections as $solr) {
+            $solr->getWriteService()->deleteByQuery('type:' . $table . ' AND uid:' . (int)$uid . ' AND siteHash:' . $siteHash);
+            if ($enableCommitsSetting) {
+                $solr->getWriteService()->commit(false, false);
+            }
+        }
+    }
+
+    /**
+     * Calls the registered post processing hooks after the garbageCollection.
+     *
+     * @param string $table
+     * @param int $uid
+     */
+    protected function callPostProcessGarbageCollectorHook($table, $uid)
+    {
+        if (!is_array($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['postProcessGarbageCollector'])) {
+            return;
+        }
+
+        foreach ($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['postProcessGarbageCollector'] as $classReference) {
+            $garbageCollectorPostProcessor = GeneralUtility::makeInstance($classReference);
+
+            if ($garbageCollectorPostProcessor instanceof GarbageCollectorPostProcessor) {
+                $garbageCollectorPostProcessor->postProcessGarbageCollector($table, $uid);
+            } else {
+                $message = get_class($garbageCollectorPostProcessor) . ' must implement interface ' .
+                    GarbageCollectorPostProcessor::class;
+                throw new \UnexpectedValueException($message, 1345807460);
+            }
+        }
+    }
+}

Classes/Domain/Index/Queue/GarbageRemover/PageStrategy.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\GarbageRemover;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2018 - Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+
+
+/**
+ * Class PageStrategy
+ */
+class PageStrategy extends AbstractStrategy {
+
+    /**
+     * @param string $table
+     * @param int $uid
+     * @return mixed
+     */
+    protected function removeGarbageOfByStrategy($table, $uid)
+    {
+        if ($table === 'tt_content') {
+            $this->collectPageGarbageByContentChange($uid);
+            return;
+        }
+
+        if ($table === 'pages') {
+            $this->collectPageGarbageByPageChange($uid);
+            return;
+        }
+    }
+
+    /**
+     * Determines the relevant page id for an content element update. Deletes the page from solr and requeues the
+     * page for a reindex.
+     *
+     * @param int $ttContentUid
+     */
+    protected function collectPageGarbageByContentChange($ttContentUid)
+    {
+        $contentElement = BackendUtility::getRecord('tt_content', $ttContentUid, 'uid, pid', '', false);
+        $this->deleteInSolrAndUpdateIndexQueue('pages', $contentElement['pid']);
+    }
+
+    /**
+     * When a page was changed it is removed from the index and index queue.
+     *
+     * @param int $uid
+     */
+    protected function collectPageGarbageByPageChange($uid)
+    {
+        $pageOverlay = BackendUtility::getRecord('pages', $uid, 'l10n_parent, sys_language_uid', '', false);
+        if (!empty($pageOverlay['l10n_parent']) && intval($pageOverlay['l10n_parent']) !== 0) {
+            $this->deleteIndexDocuments('pages', (int)$pageOverlay['l10n_parent'], (int)$pageOverlay['sys_language_uid']);
+        } else {
+            $this->deleteInSolrAndRemoveFromIndexQueue('pages', $uid);
+        }
+    }
+}

Classes/Domain/Index/Queue/GarbageRemover/RecordStrategy.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\GarbageRemover;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2018 - Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+/**
+ * Class RecordStrategy
+ */
+class RecordStrategy extends AbstractStrategy  {
+
+    /**
+     * Removes the garbage of a record.
+     *
+     * @param string $table
+     * @param int $uid
+     * @return mixed
+     */
+    protected function removeGarbageOfByStrategy($table, $uid)
+    {
+        $this->deleteInSolrAndRemoveFromIndexQueue($table, $uid);
+    }
+}

Classes/Domain/Index/Queue/GarbageRemover/StrategyFactory.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\GarbageRemover;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2018 - Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+/**
+ * Class StrategyFactory
+ */
+class StrategyFactory {
+
+    /**
+     * @param string $table
+     * @return PageStrategy|RecordStrategy
+     */
+    public static function getByTable($table)
+    {
+        $isPageRelated = in_array($table, ['tt_content','pages']);
+        return $isPageRelated ? new PageStrategy() : new RecordStrategy();
+    }
+}

Classes/Domain/Index/Queue/IndexQueueIndexingPropertyRepository.php

@@ -0,0 +1,86 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Records\AbstractRepository;
+
+/**
+ * Class IndexQueueIndexingPropertyRepository
+ * Handles all CRUD operations to tx_meilisearch_indexqueue_indexing_property table
+ */
+class IndexQueueIndexingPropertyRepository extends AbstractRepository
+{
+    /**
+     * @var string
+     */
+    protected $table = 'tx_meilisearch_indexqueue_indexing_property';
+
+    /**
+     * Removes existing indexing properties.
+     *
+     * @param int $rootPid
+     * @param int $indexQueueUid
+     * @return int
+     */
+    public function removeByRootPidAndIndexQueueUid(int $rootPid, int $indexQueueUid) : int
+    {
+        $queryBuider = $this->getQueryBuilder();
+        return $queryBuider
+            ->delete($this->table)
+            ->where(
+                $queryBuider->expr()->eq('root', $queryBuider->createNamedParameter($rootPid, \PDO::PARAM_INT)),
+                $queryBuider->expr()->eq('item_id', $queryBuider->createNamedParameter($indexQueueUid, \PDO::PARAM_INT))
+            )->execute();
+    }
+
+    /**
+     * Inserts a list of given properties
+     *
+     * @param array $properties assoc array with column names as key
+     * @return int
+     */
+    public function bulkInsert(array $properties) : int
+    {
+        return $this->getQueryBuilder()->getConnection()->bulkInsert($this->table, $properties, ['root', 'item_id', 'property_key', 'property_value']);
+    }
+
+    /**
+     * Fetches a list of properties related to index queue item
+     *
+     * @param int $indexQueueUid
+     * @return array list of records for searched index queue item
+     */
+    public function findAllByIndexQueueUid(int $indexQueueUid) : array
+    {
+        $queryBuider = $this->getQueryBuilder();
+        return $queryBuider
+            ->select('property_key', 'property_value')
+            ->from($this->table)
+            ->where(
+                $queryBuider->expr()->eq('item_id', $queryBuider->createNamedParameter($indexQueueUid, \PDO::PARAM_INT))
+            )
+            ->execute()->fetchAll();
+    }
+}

Classes/Domain/Index/Queue/QueueInitializationService.php

@@ -0,0 +1,162 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\IndexQueue\InitializationPostProcessor;
+use WapplerSystems\Meilisearch\IndexQueue\Queue;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The queue initialization service is responsible to run the initialization of the index queue for a combination of sites
+ * and index queue configurations.
+ *
+ * @author Timo Hund <timo.hund@dkd.de>
+ * @author Ingo Renner <ingo.renner@dkd.de>
+ */
+class QueueInitializationService {
+
+    /**
+     * @var Queue
+     */
+    protected $queue;
+
+    /**
+     * QueueInitializationService constructor.
+     */
+    public function __construct(Queue $queue)
+    {
+        $this->queue = $queue;
+    }
+
+    /**
+     * Truncate and rebuild the tx_meilisearch_indexqueue_item table. This is the most
+     * complete way to force reindexing, or to build the Index Queue for the
+     * first time. The Index Queue initialization is site-specific.
+     *
+     * @param Site $site The site to initialize
+     * @param string $indexingConfigurationName Name of a specific indexing configuration, when * is passed any is used
+     * @return array An array of booleans, each representing whether the
+     *      initialization for an indexing configuration was successful
+     */
+    public function initializeBySiteAndIndexConfiguration(Site $site, $indexingConfigurationName = '*'): array
+    {
+        return $this->initializeBySiteAndIndexConfigurations($site, [$indexingConfigurationName]);
+    }
+
+    /**
+     * Truncates and rebuilds the tx_meilisearch_indexqueue_item table for a set of sites and a set of index configurations.
+     *
+     * @param array $sites The array of sites to initialize
+     * @param array $indexingConfigurationNames the array of index configurations to initialize.
+     * @return array
+     */
+    public function initializeBySitesAndConfigurations(array $sites, array $indexingConfigurationNames = ['*']): array
+    {
+        $initializationStatesBySiteId = [];
+        foreach($sites as $site) {
+            /** @var  Site $site */
+            $initializationResult = $this->initializeBySiteAndIndexConfigurations($site, $indexingConfigurationNames);
+            $initializationStatesBySiteId[$site->getRootPageId()] = $initializationResult;
+        }
+
+        return $initializationStatesBySiteId;
+    }
+
+    /**
+     * Initializes a set index configurations for a given site.
+     *
+     * @param Site $site
+     * @param array $indexingConfigurationNames if one of the names is a * (wildcard) all configurations are used,
+     * @return array
+     */
+    public function initializeBySiteAndIndexConfigurations(Site $site, array $indexingConfigurationNames): array
+    {
+        $initializationStatus = [];
+
+        $hasWildcardConfiguration = in_array('*', $indexingConfigurationNames);
+        $indexingConfigurationNames = $hasWildcardConfiguration ? $site->getSolrConfiguration()->getEnabledIndexQueueConfigurationNames() : $indexingConfigurationNames;
+        foreach ($indexingConfigurationNames as $indexingConfigurationName) {
+            $initializationStatus[$indexingConfigurationName] = $this->applyInitialization($site, (string)$indexingConfigurationName);
+        }
+
+        if (!is_array($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['postProcessIndexQueueInitialization'])) {
+            return $initializationStatus;
+        }
+
+        foreach ($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['postProcessIndexQueueInitialization'] as $classReference) {
+            $indexQueueInitializationPostProcessor = GeneralUtility::makeInstance($classReference);
+            if ($indexQueueInitializationPostProcessor instanceof InitializationPostProcessor) {
+                $indexQueueInitializationPostProcessor->postProcessIndexQueueInitialization($site, $indexingConfigurationNames, $initializationStatus);
+            } else {
+                throw new \UnexpectedValueException(get_class($indexQueueInitializationPostProcessor) . ' must implement interface ' . InitializationPostProcessor::class, 1345815561);
+            }
+        }
+
+        return $initializationStatus;
+    }
+
+    /**
+     * Initializes the Index Queue for a specific indexing configuration.
+     *
+     * @param Site $site The site to initialize
+     * @param string $indexingConfigurationName name of a specific
+     *      indexing configuration
+     * @return bool TRUE if the initialization was successful, FALSE otherwise
+     */
+    protected function applyInitialization(Site $site, $indexingConfigurationName): bool
+    {
+        // clear queue
+        $this->queue->deleteItemsBySite($site, $indexingConfigurationName);
+
+        $solrConfiguration = $site->getSolrConfiguration();
+        $tableToIndex = $solrConfiguration->getIndexQueueTableNameOrFallbackToConfigurationName($indexingConfigurationName);
+        $initializerClass = $solrConfiguration->getIndexQueueInitializerClassByConfigurationName($indexingConfigurationName);
+        $indexConfiguration = $solrConfiguration->getIndexQueueConfigurationByName($indexingConfigurationName);
+
+        return $this->executeInitializer($site, $indexingConfigurationName, $initializerClass, $tableToIndex, $indexConfiguration);
+    }
+
+    /**
+     * @param Site $site
+     * @param string $indexingConfigurationName
+     * @param string $initializerClass
+     * @param string $tableToIndex
+     * @param array $indexConfiguration
+     * @return bool
+     */
+    protected function executeInitializer(Site $site, $indexingConfigurationName, $initializerClass, $tableToIndex, $indexConfiguration): bool
+    {
+        $initializer = GeneralUtility::makeInstance($initializerClass);
+        /** @var $initializer \WapplerSystems\Meilisearch\IndexQueue\Initializer\AbstractInitializer */
+        $initializer->setSite($site);
+        $initializer->setType($tableToIndex);
+        $initializer->setIndexingConfigurationName($indexingConfigurationName);
+        $initializer->setIndexingConfiguration($indexConfiguration);
+
+        return $initializer->initialize();
+    }
+
+}

Classes/Domain/Index/Queue/QueueItemRepository.php

@@ -0,0 +1,902 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\IndexQueue\Item;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use WapplerSystems\Meilisearch\System\Records\AbstractRepository;
+use Doctrine\DBAL\DBALException;
+use TYPO3\CMS\Core\Database\ConnectionPool;
+use TYPO3\CMS\Core\Database\Query\Expression\CompositeExpression;
+use TYPO3\CMS\Core\Database\Query\QueryBuilder;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Class QueueItemRepository
+ * Handles all CRUD operations to tx_meilisearch_indexqueue_item table
+ *
+ */
+class QueueItemRepository extends AbstractRepository
+{
+    /**
+     * @var string
+     */
+    protected $table = 'tx_meilisearch_indexqueue_item';
+
+    /**
+     * @var SolrLogManager
+     */
+    protected $logger;
+
+    /**
+     * QueueItemRepository constructor.
+     *
+     * @param SolrLogManager|null $logManager
+     */
+    public function __construct(SolrLogManager $logManager = null)
+    {
+        $this->logger = $logManager ?? GeneralUtility::makeInstance(SolrLogManager::class, /** @scrutinizer ignore-type */ __CLASS__);
+    }
+
+    /**
+     * Fetches the last indexed row
+     *
+     * @param int $rootPageId The root page uid for which to get the last indexed row
+     * @return array
+     */
+    public function findLastIndexedRow(int $rootPageId) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $row = $queryBuilder
+            ->select('uid', 'indexed')
+            ->from($this->table)
+            ->where($queryBuilder->expr()->eq('root', $rootPageId))
+            ->andWhere($queryBuilder->expr()->neq('indexed', 0))
+            ->orderBy('indexed', 'DESC')
+            ->setMaxResults(1)
+            ->execute()->fetchAll();
+
+        return $row;
+    }
+
+    /**
+     * Finds indexing errors for the current site
+     *
+     * @param Site $site
+     * @return array Error items for the current site's Index Queue
+     */
+    public function findErrorsBySite(Site $site) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $errors = $queryBuilder
+            ->select('uid', 'item_type', 'item_uid', 'errors')
+            ->from($this->table)
+            ->andWhere(
+                $queryBuilder->expr()->notLike('errors', $queryBuilder->createNamedParameter('')),
+                $queryBuilder->expr()->eq('root', $site->getRootPageId())
+            )
+            ->execute()->fetchAll();
+
+        return $errors;
+    }
+
+    /**
+     * Resets all the errors for all index queue items.
+     *
+     * @return int affected rows
+     */
+    public function flushAllErrors() : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $affectedRows = $this->getPreparedFlushErrorQuery($queryBuilder)->execute();
+        return $affectedRows;
+    }
+
+    /**
+     * Flushes the errors for a single site.
+     *
+     * @param Site $site
+     * @return int
+     */
+    public function flushErrorsBySite(Site $site) : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $affectedRows = $this->getPreparedFlushErrorQuery($queryBuilder)
+            ->andWhere(
+                $queryBuilder->expr()->eq('root', (int)$site->getRootPageId())
+            )
+            ->execute();
+        return $affectedRows;
+    }
+
+    /**
+     * Flushes the error for a single item.
+     *
+     * @param Item $item
+     * @return int affected rows
+     */
+    public function flushErrorByItem(Item $item) : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $affectedRows = $this->getPreparedFlushErrorQuery($queryBuilder)
+            ->andWhere(
+                $queryBuilder->expr()->eq('uid', $item->getIndexQueueUid())
+            )
+            ->execute();
+        return $affectedRows;
+    }
+
+    /**
+     * Initializes the QueryBuilder with a query the resets the error field for items that have an error.
+     *
+     * @return QueryBuilder
+     */
+    private function getPreparedFlushErrorQuery(QueryBuilder $queryBuilder)
+    {
+        return $queryBuilder
+            ->update($this->table)
+            ->set('errors', '')
+            ->where(
+                $queryBuilder->expr()->notLike('errors', $queryBuilder->createNamedParameter(''))
+            );
+    }
+
+    /**
+     * Updates an existing queue entry by $itemType $itemUid and $rootPageId.
+     *
+     * @param string $itemType The item's type, usually a table name.
+     * @param int $itemUid The item's uid, usually an integer uid, could be a
+     *      different value for non-database-record types.
+     * @param string $indexingConfiguration The name of the related indexConfiguration
+     * @param int $rootPageId The uid of the rootPage
+     * @param int $changedTime The forced change time that should be used for updating
+     * @return int affected rows
+     */
+    public function updateExistingItemByItemTypeAndItemUidAndRootPageId(string $itemType, int $itemUid, int $rootPageId, int $changedTime, string $indexingConfiguration = '') : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $queryBuilder
+            ->update($this->table)
+            ->set('changed', $changedTime)
+            ->andWhere(
+                $queryBuilder->expr()->eq('item_type', $queryBuilder->createNamedParameter($itemType)),
+                $queryBuilder->expr()->eq('item_uid', $itemUid),
+                $queryBuilder->expr()->eq('root', $rootPageId)
+            );
+
+        if (!empty($indexingConfiguration)) {
+            $queryBuilder->set('indexing_configuration', $indexingConfiguration);
+        }
+
+        return $queryBuilder->execute();
+    }
+
+    /**
+     * Adds an item to the index queue.
+     *
+     * Not meant for public use.
+     *
+     * @param string $itemType The item's type, usually a table name.
+     * @param int $itemUid The item's uid, usually an integer uid, could be a different value for non-database-record types.
+     * @param int $rootPageId
+     * @param int $changedTime
+     * @param string $indexingConfiguration The item's indexing configuration to use. Optional, overwrites existing / determined configuration.
+     * @return int the number of inserted rows, which is typically 1
+     */
+    public function add(string $itemType, int $itemUid, int $rootPageId, int $changedTime, string $indexingConfiguration) : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        return $queryBuilder
+            ->insert($this->table)
+            ->values([
+                'root' => $rootPageId,
+                'item_type' => $itemType,
+                'item_uid' => $itemUid,
+                'changed' => $changedTime,
+                'errors' => '',
+                'indexing_configuration' => $indexingConfiguration
+            ])
+            ->execute();
+
+    }
+
+    /**
+     * Retrieves the count of items that match certain filters. Each filter is passed as parts of the where claus combined with AND.
+     *
+     * @param array $sites
+     * @param array $indexQueueConfigurationNames
+     * @param array $itemTypes
+     * @param array $itemUids
+     * @param array $uids
+     * @return int
+     */
+    public function countItems(array $sites = [], array $indexQueueConfigurationNames = [], array $itemTypes = [], array $itemUids = [], array $uids = []): int
+    {
+        $rootPageIds = Site::getRootPageIdsFromSites($sites);
+        $indexQueueConfigurationList = implode(",", $indexQueueConfigurationNames);
+        $itemTypeList = implode(",", $itemTypes);
+        $itemUids = array_map("intval", $itemUids);
+        $uids = array_map("intval", $uids);
+
+        $queryBuilderForCountingItems = $this->getQueryBuilder();
+        $queryBuilderForCountingItems->count('uid')->from($this->table);
+        $queryBuilderForCountingItems = $this->addItemWhereClauses($queryBuilderForCountingItems, $rootPageIds, $indexQueueConfigurationList, $itemTypeList, $itemUids, $uids);
+
+        return (int)$queryBuilderForCountingItems->execute()->fetchColumn(0);
+    }
+
+    /**
+     * Gets the most recent changed time of a page's content elements
+     *
+     * @param int $pageUid
+     * @return int|null Timestamp of the most recent content element change or null if nothing is found.
+     */
+    public function getPageItemChangedTimeByPageUid(int $pageUid)
+    {
+        $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable('tt_content');
+        $queryBuilder->getRestrictions()->removeAll();
+        $pageContentLastChangedTime = $queryBuilder
+            ->add('select', $queryBuilder->expr()->max('tstamp', 'changed_time'))
+            ->from('tt_content')
+            ->where(
+                $queryBuilder->expr()->eq('pid', $pageUid)
+            )
+            ->execute()->fetch();
+
+        return $pageContentLastChangedTime['changed_time'];
+    }
+
+    /**
+     * Gets the most recent changed time for an item taking into account
+     * localized records.
+     *
+     * @param string $itemType The item's type, usually a table name.
+     * @param int $itemUid The item's uid
+     * @return int Timestamp of the most recent content element change
+     */
+    public function getLocalizableItemChangedTime(string $itemType, int $itemUid) : int
+    {
+        $localizedChangedTime = 0;
+
+        if (isset($GLOBALS['TCA'][$itemType]['ctrl']['transOrigPointerField'])) {
+            // table is localizable
+            $translationOriginalPointerField = $GLOBALS['TCA'][$itemType]['ctrl']['transOrigPointerField'];
+
+            $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable($itemType);
+            $queryBuilder->getRestrictions()->removeAll();
+            $localizedChangedTime = $queryBuilder
+                ->add('select', $queryBuilder->expr()->max('tstamp', 'changed_time'))
+                ->from($itemType)
+                ->orWhere(
+                    $queryBuilder->expr()->eq('uid', $itemUid),
+                    $queryBuilder->expr()->eq($translationOriginalPointerField, $itemUid)
+                )->execute()->fetchColumn(0);
+        }
+
+        return (int)$localizedChangedTime;
+    }
+
+    /**
+     * Returns prepared QueryBuilder for contains* methods in this repository
+     *
+     * @param string $itemType
+     * @param int $itemUid
+     * @return QueryBuilder
+     */
+    protected function getQueryBuilderForContainsMethods(string $itemType, int $itemUid) : QueryBuilder
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        return $queryBuilder->count('uid')->from($this->table)
+            ->andWhere(
+                $queryBuilder->expr()->eq('item_type', $queryBuilder->createNamedParameter($itemType)),
+                $queryBuilder->expr()->eq('item_uid', $itemUid)
+            );
+    }
+
+    /**
+     * Checks whether the Index Queue contains a specific item.
+     *
+     * @param string $itemType The item's type, usually a table name.
+     * @param int $itemUid The item's uid
+     * @return bool TRUE if the item is found in the queue, FALSE otherwise
+     */
+    public function containsItem(string $itemType, int $itemUid) : bool
+    {
+        return (bool)$this->getQueryBuilderForContainsMethods($itemType, $itemUid)->execute()->fetchColumn(0);
+    }
+
+    /**
+     * Checks whether the Index Queue contains a specific item.
+     *
+     * @param string $itemType The item's type, usually a table name.
+     * @param int $itemUid The item's uid
+     * @param integer $rootPageId
+     * @return bool TRUE if the item is found in the queue, FALSE otherwise
+     */
+    public function containsItemWithRootPageId(string $itemType, int $itemUid, int $rootPageId) : bool
+    {
+        $queryBuilder = $this->getQueryBuilderForContainsMethods($itemType, $itemUid);
+        return (bool)$queryBuilder
+            ->andWhere($queryBuilder->expr()->eq('root', $rootPageId))
+            ->execute()->fetchColumn(0);
+    }
+
+    /**
+     * Checks whether the Index Queue contains a specific item that has been
+     * marked as indexed.
+     *
+     * @param string $itemType The item's type, usually a table name.
+     * @param int $itemUid The item's uid
+     * @return bool TRUE if the item is found in the queue and marked as
+     *      indexed, FALSE otherwise
+     */
+    public function containsIndexedItem(string $itemType, int $itemUid) : bool
+    {
+        $queryBuilder = $this->getQueryBuilderForContainsMethods($itemType, $itemUid);
+        return (bool)$queryBuilder
+            ->andWhere($queryBuilder->expr()->gt('indexed', 0))
+            ->execute()->fetchColumn(0);
+    }
+
+    /**
+     * Removes an item from the Index Queue.
+     *
+     * @param string $itemType The type of the item to remove, usually a table name.
+     * @param int $itemUid The uid of the item to remove
+     */
+    public function deleteItem(string $itemType, int $itemUid = null)
+    {
+        $itemUids = empty($itemUid) ? [] : [$itemUid];
+        $this->deleteItems([], [], [$itemType], $itemUids);
+    }
+
+    /**
+     * Removes all items of a certain type from the Index Queue.
+     *
+     * @param string $itemType The type of items to remove, usually a table name.
+     */
+    public function deleteItemsByType(string $itemType)
+    {
+        $this->deleteItem($itemType);
+    }
+
+    /**
+     * Removes all items of a certain site from the Index Queue. Accepts an
+     * optional parameter to limit the deleted items by indexing configuration.
+     *
+     * @param Site $site The site to remove items for.
+     * @param string $indexingConfigurationName Name of a specific indexing configuration
+     * @throws \Exception
+     */
+    public function deleteItemsBySite(Site $site, string $indexingConfigurationName = '')
+    {
+        $indexingConfigurationNames = empty($indexingConfigurationName) ? [] : [$indexingConfigurationName];
+        $this->deleteItems([$site], $indexingConfigurationNames);
+    }
+
+    /**
+     * Removes items in the index queue filtered by the passed arguments.
+     *
+     * @param array $sites
+     * @param array $indexQueueConfigurationNames
+     * @param array $itemTypes
+     * @param array $itemUids
+     * @param array $uids
+     * @throws \Exception
+     */
+    public function deleteItems(array $sites = [], array $indexQueueConfigurationNames = [], array $itemTypes = [], array $itemUids = [], array $uids = [])
+    {
+        $rootPageIds = Site::getRootPageIdsFromSites($sites);
+        $indexQueueConfigurationList = implode(",", $indexQueueConfigurationNames);
+        $itemTypeList = implode(",", $itemTypes);
+        $itemUids = array_map("intval", $itemUids);
+        $uids = array_map("intval", $uids);
+
+        $queryBuilderForDeletingItems = $this->getQueryBuilder();
+        $queryBuilderForDeletingItems->delete($this->table);
+        $queryBuilderForDeletingItems = $this->addItemWhereClauses($queryBuilderForDeletingItems, $rootPageIds, $indexQueueConfigurationList, $itemTypeList, $itemUids, $uids);
+
+        $queryBuilderForDeletingProperties = $this->buildQueryForPropertyDeletion($queryBuilderForDeletingItems, $rootPageIds, $indexQueueConfigurationList, $itemTypeList, $itemUids, $uids);
+
+        $queryBuilderForDeletingItems->getConnection()->beginTransaction();
+        try {
+            $queryBuilderForDeletingItems->execute();
+            $queryBuilderForDeletingProperties->execute();
+
+            $queryBuilderForDeletingItems->getConnection()->commit();
+        } catch (\Exception $e) {
+            $queryBuilderForDeletingItems->getConnection()->rollback();
+            throw $e;
+        }
+    }
+
+    /**
+     * Initializes the query builder to delete items in the index queue filtered by the passed arguments.
+     *
+     * @param array $rootPageIds filter on a set of rootPageUids.
+     * @param string $indexQueueConfigurationList
+     * @param string $itemTypeList
+     * @param array $itemUids filter on a set of item uids
+     * @param array $uids filter on a set of queue item uids
+     * @return QueryBuilder
+     */
+    private function addItemWhereClauses(QueryBuilder $queryBuilderForDeletingItems, array $rootPageIds, string $indexQueueConfigurationList, string $itemTypeList, array $itemUids, array $uids): QueryBuilder
+    {
+
+        if (!empty($rootPageIds)) {
+            $queryBuilderForDeletingItems->andWhere($queryBuilderForDeletingItems->expr()->in('root', $rootPageIds));
+        };
+
+        if (!empty($indexQueueConfigurationList)) {
+            $queryBuilderForDeletingItems->andWhere($queryBuilderForDeletingItems->expr()->in('indexing_configuration', $queryBuilderForDeletingItems->createNamedParameter($indexQueueConfigurationList)));
+        }
+
+        if (!empty($itemTypeList)) {
+            $queryBuilderForDeletingItems->andWhere($queryBuilderForDeletingItems->expr()->in('item_type', $queryBuilderForDeletingItems->createNamedParameter($itemTypeList)));
+        }
+
+        if (!empty($itemUids)) {
+            $queryBuilderForDeletingItems->andWhere($queryBuilderForDeletingItems->expr()->in('item_uid', $itemUids));
+        }
+
+        if (!empty($uids)) {
+            $queryBuilderForDeletingItems->andWhere($queryBuilderForDeletingItems->expr()->in('uid', $uids));
+        }
+
+        return $queryBuilderForDeletingItems;
+    }
+
+    /**
+     * Initializes a query builder to delete the indexing properties of an item by the passed conditions.
+     *
+     * @param QueryBuilder $queryBuilderForDeletingItems
+     * @param array $rootPageIds
+     * @param string $indexQueueConfigurationList
+     * @param string $itemTypeList
+     * @param array $itemUids
+     * @param array $uids
+     * @return QueryBuilder
+     */
+    private function buildQueryForPropertyDeletion(QueryBuilder $queryBuilderForDeletingItems, array $rootPageIds, string $indexQueueConfigurationList, string $itemTypeList, array $itemUids, array $uids): QueryBuilder
+    {
+        $queryBuilderForSelectingProperties = $queryBuilderForDeletingItems->getConnection()->createQueryBuilder();
+        $queryBuilderForSelectingProperties->select('items.uid')->from('tx_meilisearch_indexqueue_indexing_property', 'properties')->innerJoin(
+            'properties',
+            $this->table,
+            'items',
+            (string)$queryBuilderForSelectingProperties->expr()->andX(
+                $queryBuilderForSelectingProperties->expr()->eq('items.uid', $queryBuilderForSelectingProperties->quoteIdentifier('properties.item_id')),
+                empty($rootPageIds) ? '' : $queryBuilderForSelectingProperties->expr()->in('items.root', $rootPageIds),
+                empty($indexQueueConfigurationList) ? '' : $queryBuilderForSelectingProperties->expr()->in('items.indexing_configuration', $queryBuilderForSelectingProperties->createNamedParameter($indexQueueConfigurationList)),
+                empty($itemTypeList) ? '' : $queryBuilderForSelectingProperties->expr()->in('items.item_type', $queryBuilderForSelectingProperties->createNamedParameter($itemTypeList)),
+                empty($itemUids) ? '' : $queryBuilderForSelectingProperties->expr()->in('items.item_uid', $itemUids),
+                empty($uids) ? '' : $queryBuilderForSelectingProperties->expr()->in('items.uid', $uids)
+            )
+        );
+        $propertyEntriesToDelete = implode(',', array_column($queryBuilderForSelectingProperties->execute()->fetchAll(), 'uid'));
+
+        $queryBuilderForDeletingProperties = $queryBuilderForDeletingItems->getConnection()->createQueryBuilder();
+
+        // make sure executing the propety deletion query doesn't fail if there are no properties to delete
+        if (empty($propertyEntriesToDelete)) {
+            $propertyEntriesToDelete = '0';
+        }
+
+        $queryBuilderForDeletingProperties->delete('tx_meilisearch_indexqueue_indexing_property')->where(
+            $queryBuilderForDeletingProperties->expr()->in('item_id', $propertyEntriesToDelete)
+        );
+
+        return $queryBuilderForDeletingProperties;
+    }
+
+    /**
+     * Removes all items from the Index Queue.
+     *
+     * @return int The number of affected rows. For a truncate this is unreliable as theres no meaningful information.
+     */
+    public function deleteAllItems()
+    {
+        return $this->getQueryBuilder()->getConnection()->truncate($this->table);
+    }
+
+    /**
+     * Gets a single Index Queue item by its uid.
+     *
+     * @param int $uid Index Queue item uid
+     * @return Item|null The request Index Queue item or NULL if no item with $itemId was found
+     */
+    public function findItemByUid(int $uid)
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $indexQueueItemRecord = $queryBuilder
+            ->select('*')
+            ->from($this->table)
+            ->where($queryBuilder->expr()->eq('uid', $uid))
+            ->execute()->fetch();
+
+        if (!isset($indexQueueItemRecord['uid'])) {
+            return null;
+        }
+
+        /** @var Item $item*/
+        $item = GeneralUtility::makeInstance(Item::class, /** @scrutinizer ignore-type */ $indexQueueItemRecord);
+        return $item;
+    }
+
+    /**
+     * Gets Index Queue items by type and uid.
+     *
+     * @param string $itemType item type, usually  the table name
+     * @param int $itemUid item uid
+     * @return Item[] An array of items matching $itemType and $itemUid
+     */
+    public function findItemsByItemTypeAndItemUid(string $itemType, int $itemUid) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $compositeExpression = $queryBuilder->expr()->andX(
+            $queryBuilder->expr()->eq('item_type', $queryBuilder->getConnection()->quote($itemType, \PDO::PARAM_STR)),
+            $queryBuilder->expr()->eq('item_uid', $itemUid)
+        );
+        return $this->getItemsByCompositeExpression($compositeExpression, $queryBuilder);
+    }
+
+    /**
+     * Returns a collection of items by CompositeExpression.
+     * D
+     *
+     * @param CompositeExpression|null $expression Optional expression to filter records.
+     * @param QueryBuilder|null $queryBuilder QueryBuilder to use
+     * @return array
+     */
+    protected function getItemsByCompositeExpression(CompositeExpression $expression = null, QueryBuilder $queryBuilder = null) : array
+    {
+        if (!$queryBuilder instanceof QueryBuilder) {
+            $queryBuilder = $this->getQueryBuilder();
+        }
+
+        $queryBuilder->select('*')->from($this->table);
+        if (isset($expression)) {
+            $queryBuilder->where($expression);
+        }
+
+        $indexQueueItemRecords = $queryBuilder->execute()->fetchAll();
+        return $this->getIndexQueueItemObjectsFromRecords($indexQueueItemRecords);
+    }
+
+    /**
+     * Returns all items in the queue.
+     *
+     * @return Item[] all Items from Queue without restrictions
+     */
+    public function findAll() : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $allRecords = $queryBuilder
+            ->select('*')
+            ->from($this->table)
+            ->execute()->fetchAll();
+        return $this->getIndexQueueItemObjectsFromRecords($allRecords);
+    }
+
+    /**
+     * Gets $limit number of items to index for a particular $site.
+     *
+     * @param Site $site TYPO3 site
+     * @param int $limit Number of items to get from the queue
+     * @return Item[] Items to index to the given solr server
+     */
+    public function findItemsToIndex(Site $site, int $limit = 50) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        // determine which items to index with this run
+        $indexQueueItemRecords = $queryBuilder
+            ->select('*')
+            ->from($this->table)
+            ->andWhere(
+                $queryBuilder->expr()->eq('root', $site->getRootPageId()),
+                $queryBuilder->expr()->gt('changed', 'indexed'),
+                $queryBuilder->expr()->lte('changed', time()),
+                $queryBuilder->expr()->eq('errors', $queryBuilder->createNamedParameter(''))
+            )
+            ->orderBy('indexing_priority', 'DESC')
+            ->addOrderBy('changed', 'DESC')
+            ->addOrderBy('uid', 'DESC')
+            ->setMaxResults($limit)
+            ->execute()->fetchAll();
+
+        return $this->getIndexQueueItemObjectsFromRecords($indexQueueItemRecords);
+    }
+
+    /**
+     * Retrieves the count of items that match certain filters. Each filter is passed as parts of the where claus combined with AND.
+     *
+     * @param array $sites
+     * @param array $indexQueueConfigurationNames
+     * @param array $itemTypes
+     * @param array $itemUids
+     * @param array $uids
+     * @param int $start
+     * @param int $limit
+     * @return array
+     */
+    public function findItems(array $sites = [], array $indexQueueConfigurationNames = [], array $itemTypes = [], array $itemUids = [], array $uids = [], $start = 0, $limit = 50): array
+    {
+        $rootPageIds = Site::getRootPageIdsFromSites($sites);
+        $indexQueueConfigurationList = implode(",", $indexQueueConfigurationNames);
+        $itemTypeList = implode(",", $itemTypes);
+        $itemUids = array_map("intval", $itemUids);
+        $uids = array_map("intval", $uids);
+        $itemQueryBuilder = $this->getQueryBuilder()->select('*')->from($this->table);
+        $itemQueryBuilder = $this->addItemWhereClauses($itemQueryBuilder, $rootPageIds, $indexQueueConfigurationList, $itemTypeList, $itemUids, $uids);
+        $itemRecords = $itemQueryBuilder->setFirstResult($start)->setMaxResults($limit)->execute()->fetchAll();
+        return $this->getIndexQueueItemObjectsFromRecords($itemRecords);
+    }
+
+    /**
+     * Creates an array of WapplerSystems\Meilisearch\IndexQueue\Item objects from an array of
+     * index queue records.
+     *
+     * @param array $indexQueueItemRecords Array of plain index queue records
+     * @return array Array of WapplerSystems\Meilisearch\IndexQueue\Item objects
+     */
+    protected function getIndexQueueItemObjectsFromRecords(array $indexQueueItemRecords) : array
+    {
+        $tableRecords = $this->getAllQueueItemRecordsByUidsGroupedByTable($indexQueueItemRecords);
+        return $this->getQueueItemObjectsByRecords($indexQueueItemRecords, $tableRecords);
+    }
+
+    /**
+     * Returns the records for suitable item type.
+     *
+     * @param array $indexQueueItemRecords
+     * @return array
+     */
+    protected function getAllQueueItemRecordsByUidsGroupedByTable(array $indexQueueItemRecords) : array
+    {
+        $tableUids = [];
+        $tableRecords = [];
+        // grouping records by table
+        foreach ($indexQueueItemRecords as $indexQueueItemRecord) {
+            $tableUids[$indexQueueItemRecord['item_type']][] = $indexQueueItemRecord['item_uid'];
+        }
+
+        // fetching records by table, saves us a lot of single queries
+        foreach ($tableUids as $table => $uids) {
+            $uidList = implode(',', $uids);
+
+            $queryBuilderForRecordTable = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable($table);
+            $queryBuilderForRecordTable->getRestrictions()->removeAll();
+            $resultsFromRecordTable = $queryBuilderForRecordTable
+                ->select('*')
+                ->from($table)
+                ->where($queryBuilderForRecordTable->expr()->in('uid', $uidList))
+                ->execute();
+            $records = [];
+            while ($record = $resultsFromRecordTable->fetch()) {
+                $records[$record['uid']] = $record;
+            }
+
+            $tableRecords[$table] = $records;
+            $this->hookPostProcessFetchRecordsForIndexQueueItem($table, $uids, $tableRecords);
+        }
+
+        return $tableRecords;
+    }
+
+    /**
+     * Calls defined in postProcessFetchRecordsForIndexQueueItem hook method.
+     *
+     * @param string $table
+     * @param array $uids
+     * @param array $tableRecords
+     *
+     * @return void
+     */
+    protected function hookPostProcessFetchRecordsForIndexQueueItem(string $table, array $uids, array &$tableRecords)
+    {
+        if (!is_array($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['postProcessFetchRecordsForIndexQueueItem'])) {
+            return;
+        }
+        $params = ['table' => $table, 'uids' => $uids, 'tableRecords' => &$tableRecords];
+        foreach ($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['postProcessFetchRecordsForIndexQueueItem'] as $reference) {
+            GeneralUtility::callUserFunction($reference, $params, $this);
+        }
+    }
+
+    /**
+     * Instantiates a list of Item objects from database records.
+     *
+     * @param array $indexQueueItemRecords records from database
+     * @param array $tableRecords
+     * @return array
+     */
+    protected function getQueueItemObjectsByRecords(array $indexQueueItemRecords, array $tableRecords) : array
+    {
+        $indexQueueItems = [];
+        foreach ($indexQueueItemRecords as $indexQueueItemRecord) {
+            if (isset($tableRecords[$indexQueueItemRecord['item_type']][$indexQueueItemRecord['item_uid']])) {
+                $indexQueueItems[] = GeneralUtility::makeInstance(
+                    Item::class,
+                    /** @scrutinizer ignore-type */ $indexQueueItemRecord,
+                    /** @scrutinizer ignore-type */ $tableRecords[$indexQueueItemRecord['item_type']][$indexQueueItemRecord['item_uid']]
+                );
+            } else {
+                $this->logger->log(
+                    SolrLogManager::ERROR,
+                    'Record missing for Index Queue item. Item removed.',
+                    [
+                        $indexQueueItemRecord
+                    ]
+                );
+                $this->deleteItem($indexQueueItemRecord['item_type'],
+                    $indexQueueItemRecord['item_uid']);
+            }
+        }
+
+        return $indexQueueItems;
+    }
+
+    /**
+     * Marks an item as failed and causes the indexer to skip the item in the
+     * next run.
+     *
+     * @param int|Item $item Either the item's Index Queue uid or the complete item
+     * @param string $errorMessage Error message
+     * @return int affected rows
+     */
+    public function markItemAsFailed($item, string $errorMessage = ''): int
+    {
+        $itemUid = ($item instanceof Item) ? $item->getIndexQueueUid() : (int)$item;
+        $errorMessage = empty($errorMessage) ? '1' : $errorMessage;
+
+        $queryBuilder = $this->getQueryBuilder();
+        return (int)$queryBuilder
+            ->update($this->table)
+            ->set('errors', $errorMessage)
+            ->where($queryBuilder->expr()->eq('uid', $itemUid))
+            ->execute();
+    }
+
+    /**
+     * Sets the timestamp of when an item last has been indexed.
+     *
+     * @param Item $item
+     * @return int affected rows
+     */
+    public function updateIndexTimeByItem(Item $item) : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        return (int)$queryBuilder
+            ->update($this->table)
+            ->set('indexed', time())
+            ->where($queryBuilder->expr()->eq('uid', $item->getIndexQueueUid()))
+            ->execute();
+    }
+
+    /**
+     * Sets the change timestamp of an item.
+     *
+     * @param Item $item
+     * @param int $changedTime
+     * @return int affected rows
+     */
+    public function updateChangedTimeByItem(Item $item, int $changedTime) : int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        return (int)$queryBuilder
+            ->update($this->table)
+            ->set('changed', $changedTime)
+            ->where($queryBuilder->expr()->eq('uid', $item->getIndexQueueUid()))
+            ->execute();
+    }
+
+    /**
+     * Initializes Queue by given sql
+     *
+     * Note: Do not use platform specific functions!
+     *
+     * @param string $sqlStatement Native SQL statement
+     * @return int The number of affected rows.
+     * @internal
+     * @throws DBALException
+     */
+    public function initializeByNativeSQLStatement(string $sqlStatement) : int
+    {
+        return $this->getQueryBuilder()->getConnection()->exec($sqlStatement);
+    }
+
+    /**
+     * Retrieves an array of pageIds from mountPoints that allready have a queue entry.
+     *
+     * @param string $identifier identifier of the mount point
+     * @return array pageIds from mountPoints that allready have a queue entry
+     */
+    public function findPageIdsOfExistingMountPagesByMountIdentifier(string $identifier) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $resultSet = $queryBuilder
+            ->select('item_uid')
+            ->add('select', $queryBuilder->expr()->count('*', 'queueItemCount'), true)
+            ->from($this->table)
+            ->where(
+                $queryBuilder->expr()->eq('item_type', $queryBuilder->createNamedParameter('pages')),
+                $queryBuilder->expr()->eq('pages_mountidentifier', $queryBuilder->createNamedParameter($identifier))
+            )
+            ->groupBy('item_uid')
+            ->execute();
+
+        $mountedPagesIdsWithQueueItems = [];
+        while ($record = $resultSet->fetch()) {
+            if ($record['queueItemCount'] > 0) {
+                $mountedPagesIdsWithQueueItems[] = $record['item_uid'];
+            }
+        }
+
+        return $mountedPagesIdsWithQueueItems;
+    }
+
+    /**
+     * Retrieves an array of items for mount destinations mathed by root page ID, Mount Identifier and a list of mounted page IDs.
+     *
+     * @param int $rootPid
+     * @param string $identifier identifier of the mount point
+     * @param array $mountedPids An array of mounted page IDs
+     * @return array
+     */
+    public function findAllIndexQueueItemsByRootPidAndMountIdentifierAndMountedPids(int $rootPid, string $identifier, array $mountedPids) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        return $queryBuilder
+            ->select('*')
+            ->from($this->table)
+            ->where(
+                $queryBuilder->expr()->eq('root', $queryBuilder->createNamedParameter($rootPid, \PDO::PARAM_INT)),
+                $queryBuilder->expr()->eq('item_type', $queryBuilder->createNamedParameter('pages')),
+                $queryBuilder->expr()->in('item_uid', $mountedPids),
+                $queryBuilder->expr()->eq('has_indexing_properties', $queryBuilder->createNamedParameter(1, \PDO::PARAM_INT)),
+                $queryBuilder->expr()->eq('pages_mountidentifier', $queryBuilder->createNamedParameter($identifier))
+            )
+            ->execute()->fetchAll();
+    }
+
+    /**
+     * Updates has_indexing_properties field for given Item
+     *
+     * @param int $itemUid
+     * @param bool $hasIndexingPropertiesFlag
+     * @return int number of affected rows, 1 on success
+     */
+    public function updateHasIndexingPropertiesFlagByItemUid(int $itemUid, bool $hasIndexingPropertiesFlag): int
+    {
+        $queryBuilder = $this->getQueryBuilder();
+
+        return $queryBuilder
+            ->update($this->table)
+            ->where($queryBuilder->expr()->eq('uid', $queryBuilder->createNamedParameter($itemUid, \PDO::PARAM_INT)))
+            ->set('has_indexing_properties', $queryBuilder->createNamedParameter($hasIndexingPropertiesFlag, \PDO::PARAM_INT), false)
+            ->execute();
+    }
+}

Classes/Domain/Index/Queue/RecordMonitor/Helper/ConfigurationAwareRecordService.php

@@ -0,0 +1,186 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\RecordMonitor\Helper;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 - Thomas Hohn <tho@systime.dk>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Cache\TwoLevelCache;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Extracted logic from the AbstractDataHandlerListener in order to
+ * handle ConfigurationAwareRecords
+ *
+ * @author Thomas Hohn Hund <tho@systime.dk>
+ */
+class ConfigurationAwareRecordService
+{
+    /**
+     * Retrieves the name of the Index Queue Configuration for a record.
+     *
+     * @param string $recordTable Table to read from
+     * @param int $recordUid Id of the record
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return string|null Name of indexing configuration
+     */
+    public function getIndexingConfigurationName($recordTable, $recordUid, TypoScriptConfiguration $solrConfiguration)
+    {
+        $name = null;
+        $indexingConfigurations = $solrConfiguration->getEnabledIndexQueueConfigurationNames();
+        foreach ($indexingConfigurations as $indexingConfigurationName) {
+            if (!$solrConfiguration->getIndexQueueConfigurationIsEnabled($indexingConfigurationName)) {
+                // ignore disabled indexing configurations
+                continue;
+            }
+
+            $record = $this->getRecordIfIndexConfigurationIsValid($recordTable, $recordUid,
+                $indexingConfigurationName, $solrConfiguration);
+            if (!empty($record)) {
+                $name = $indexingConfigurationName;
+                // FIXME currently returns after the first configuration match
+                break;
+            }
+        }
+
+        return $name;
+    }
+
+    /**
+     * Retrieves a record, taking into account the additionalWhereClauses of the
+     * Indexing Queue configurations.
+     *
+     * @param string $recordTable Table to read from
+     * @param int $recordUid Id of the record
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return array Record if found, otherwise empty array
+     */
+    public function getRecord($recordTable, $recordUid, TypoScriptConfiguration $solrConfiguration)
+    {
+        $record = [];
+        $indexingConfigurations = $solrConfiguration->getEnabledIndexQueueConfigurationNames();
+        foreach ($indexingConfigurations as $indexingConfigurationName) {
+            $record = $this->getRecordIfIndexConfigurationIsValid($recordTable, $recordUid,
+                $indexingConfigurationName, $solrConfiguration);
+            if (!empty($record)) {
+                // if we found a record which matches the conditions, we can continue
+                break;
+            }
+        }
+        return $record;
+    }
+
+    /**
+     * This method return the record array if the table is valid for this indexingConfiguration.
+     * Otherwise an empty array will be returned.
+     *
+     * @param string $recordTable
+     * @param integer $recordUid
+     * @param string $indexingConfigurationName
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return array
+     */
+    protected function getRecordIfIndexConfigurationIsValid($recordTable, $recordUid, $indexingConfigurationName, TypoScriptConfiguration $solrConfiguration)
+    {
+        if (!$this->isValidTableForIndexConfigurationName($recordTable, $indexingConfigurationName, $solrConfiguration)) {
+            return [];
+        }
+
+        $recordWhereClause = $solrConfiguration->getIndexQueueAdditionalWhereClauseByConfigurationName($indexingConfigurationName);
+
+        $row = $this->getRecordForIndexConfigurationIsValid($recordTable, $recordUid, $recordWhereClause);
+
+        return $row;
+    }
+
+    /**
+     * Returns the row need by getRecordIfIndexConfigurationIsValid either directly from database
+     * or from cache
+     *
+     * @param string $recordTable
+     * @param integer $recordUid
+     * @param string $recordWhereClause
+     *
+     * @return array
+     */
+    protected function getRecordForIndexConfigurationIsValid($recordTable, $recordUid, $recordWhereClause)
+    {
+        $cache = GeneralUtility::makeInstance(TwoLevelCache::class, /** @scrutinizer ignore-type */ 'cache_runtime');
+        $cacheId = md5('ConfigurationAwareRecordService' . ':' . 'getRecordIfIndexConfigurationIsValid' . ':' . $recordTable . ':' . $recordUid . ':' . $recordWhereClause);
+
+        $row = $cache->get($cacheId);
+        if (!empty($row)) {
+            return $row;
+        }
+
+        $row = (array)BackendUtility::getRecord($recordTable, $recordUid, '*', $recordWhereClause);
+        $cache->set($cacheId, $row);
+
+        return $row;
+    }
+
+    /**
+     * This method is used to check if a table is an allowed table for an index configuration.
+     *
+     * @param string $recordTable
+     * @param string $indexingConfigurationName
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return boolean
+     */
+    protected function isValidTableForIndexConfigurationName($recordTable, $indexingConfigurationName, TypoScriptConfiguration $solrConfiguration)
+    {
+        $tableToIndex = $solrConfiguration->getIndexQueueTableNameOrFallbackToConfigurationName($indexingConfigurationName);
+
+        $isMatchingTable = ($tableToIndex === $recordTable);
+
+        if ($isMatchingTable) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * This method retrieves the parent pages record when the parent record is accessible
+     * through the recordWhereClause
+     *
+     * @param int $recordUid
+     * @param string $parentWhereClause
+     * @return array
+     */
+    protected function getPageOverlayRecordIfParentIsAccessible($recordUid, $parentWhereClause)
+    {
+        $overlayRecord = (array)BackendUtility::getRecord('pages', $recordUid, '*');
+        $overlayParentId = $overlayRecord['l10n_parent'];
+
+        $pageRecord = (array)BackendUtility::getRecord('pages', $overlayParentId, '*', $parentWhereClause);
+
+        if (empty($pageRecord)) {
+            return [];
+        }
+
+        return $overlayRecord;
+    }
+}

Classes/Domain/Index/Queue/RecordMonitor/Helper/MountPagesUpdater.php

@@ -0,0 +1,112 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\RecordMonitor\Helper;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2015-2016 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\IndexQueue\Initializer\Page;
+use WapplerSystems\Meilisearch\System\Page\Rootline;
+use WapplerSystems\Meilisearch\System\Records\Pages\PagesRepository;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Core\Utility\RootlineUtility;
+use TYPO3\CMS\Frontend\Page\PageRepository;
+
+/**
+ * Extracted logic from the RecordMonitor to trigger mount page updates.
+ *
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class MountPagesUpdater
+{
+
+    /**
+     * @var PagesRepository
+     */
+    protected $pagesRepository;
+
+    /**
+     * MountPagesUpdater constructor.
+     *
+     * @param PagesRepository|null $pagesRepository
+     */
+    public function __construct(PagesRepository $pagesRepository = null) {
+        $this->pagesRepository = $pagesRepository ?? GeneralUtility::makeInstance(PagesRepository::class);
+    }
+
+    /**
+     * Handles updates of the Index Queue in case a newly created or changed
+     * page is part of a tree that is mounted into a another site.
+     *
+     * @param int $pageId Page Id (uid).
+     */
+    public function update($pageId)
+    {
+        // get the root line of the page, every parent page could be a Mount Page source
+        $rootlineUtility = GeneralUtility::makeInstance(RootlineUtility::class, $pageId);
+        try {
+            $rootLineArray = $rootlineUtility->get();
+        } catch (\RuntimeException $e) {
+            $rootLineArray = [];
+        }
+
+        $currentPage = array_shift($rootLineArray);
+        $currentPageUid = (int)$currentPage['uid'];
+
+        if (empty($rootLineArray) && $currentPageUid === 0) {
+            return;
+        }
+
+        /** @var $rootLine Rootline */
+        $rootLine = GeneralUtility::makeInstance(Rootline::class, /** @scrutinizer ignore-type */ $rootLineArray);
+        $rootLineParentPageIds = array_map('intval', $rootLine->getParentPageIds());
+        $destinationMountProperties = $this->pagesRepository->findMountPointPropertiesByPageIdOrByRootLineParentPageIds($currentPageUid, $rootLineParentPageIds);
+
+        if (empty($destinationMountProperties)) {
+            return;
+        }
+
+        foreach ($destinationMountProperties as $destinationMount) {
+            $this->addPageToMountingSiteIndexQueue($pageId, $destinationMount);
+        }
+    }
+
+    /**
+     * Adds a page to the Index Queue of a site mounting the page.
+     *
+     * @param int $mountedPageId ID (uid) of the mounted page.
+     * @param array $mountProperties Array of mount point properties mountPageSource, mountPageDestination, and mountPageOverlayed
+     */
+    protected function addPageToMountingSiteIndexQueue($mountedPageId, array $mountProperties)
+    {
+        $siteRepository = GeneralUtility::makeInstance(SiteRepository::class);
+        $mountingSite = $siteRepository->getSiteByPageId($mountProperties['mountPageDestination']);
+
+        /** @var $pageInitializer Page */
+        $pageInitializer = GeneralUtility::makeInstance(Page::class);
+        $pageInitializer->setSite($mountingSite);
+
+        $pageInitializer->initializeMountedPage($mountProperties, $mountedPageId);
+    }
+}

Classes/Domain/Index/Queue/RecordMonitor/Helper/RootPageResolver.php

@@ -0,0 +1,315 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\RecordMonitor\Helper;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017- Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use WapplerSystems\Meilisearch\System\Cache\TwoLevelCache;
+use WapplerSystems\Meilisearch\System\Configuration\ExtensionConfiguration;
+use WapplerSystems\Meilisearch\System\Page\Rootline;
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\SingletonInterface;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Core\Utility\RootlineUtility;
+use TYPO3\CMS\Frontend\Page\PageRepository;
+
+/**
+ * RootPageResolver.
+ *
+ * Responsibility: The RootPageResolver is responsible to determine all relevant site root page id's
+ * for a certain records, by table and uid.
+ *
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class RootPageResolver implements SingletonInterface
+{
+
+    /**
+     * @var ConfigurationAwareRecordService
+     */
+    protected $recordService;
+
+    /**
+     * @var TwoLevelCache
+     */
+    protected $runtimeCache;
+
+    /**
+     * @var ExtensionConfiguration
+     */
+    protected $extensionConfiguration;
+
+    /**
+     * RootPageResolver constructor.
+     * @param ConfigurationAwareRecordService|null $recordService
+     * @param TwoLevelCache|null $twoLevelCache
+     */
+    public function __construct(ConfigurationAwareRecordService $recordService = null, TwoLevelCache $twoLevelCache = null)
+    {
+        $this->recordService = $recordService ?? GeneralUtility::makeInstance(ConfigurationAwareRecordService::class);
+        $this->runtimeCache = $twoLevelCache ?? GeneralUtility::makeInstance(TwoLevelCache::class, /** @scrutinizer ignore-type */ 'cache_runtime');
+        $this->extensionConfiguration = GeneralUtility::makeInstance(ExtensionConfiguration::class);
+    }
+
+    /**
+     * This method determines the responsible site roots for a record by getting the rootPage of the record and checking
+     * if the pid is references in another site with additionalPageIds and returning those rootPageIds as well.
+     * The result is cached by the caching framework.
+     *
+     * @param string $table
+     * @param int $uid
+     * @return array
+     */
+    public function getResponsibleRootPageIds($table, $uid)
+    {
+        $cacheId = 'RootPageResolver' . '_' . 'getResponsibleRootPageIds' . '_' . $table . '_' . $uid;
+        $methodResult = $this->runtimeCache->get($cacheId);
+        if (!empty($methodResult)) {
+            return $methodResult;
+        }
+
+        $methodResult = $this->buildResponsibleRootPageIds($table, $uid);
+        $this->runtimeCache->set($cacheId, $methodResult);
+
+        return $methodResult;
+    }
+
+    /**
+     * Checks if the passed pageId is a root page.
+     *
+     * @param int $pageId Page ID
+     * @return bool TRUE if the page is marked as root page, FALSE otherwise
+     */
+    public function getIsRootPageId($pageId)
+    {
+        // Page 0 can never be a root page
+        if ($pageId === 0) {
+            return false;
+        }
+
+        // Page -1 is a workspace thing
+        if ($pageId === -1) {
+            return false;
+        }
+
+        $cacheId = 'RootPageResolver' . '_' . 'getIsRootPageId' . '_' . $pageId;
+        $isSiteRoot = $this->runtimeCache->get($cacheId);
+
+        if (!empty($isSiteRoot)) {
+            return $isSiteRoot;
+        }
+
+        $page = $this->getPageRecordByPageId($pageId);
+        if (empty($page)) {
+            throw new \InvalidArgumentException(
+                'The page for the given page ID \'' . $pageId
+                . '\' could not be found in the database and can therefore not be used as site root page.',
+                1487171426
+            );
+        }
+
+        $isSiteRoot = Site::isRootPage($page);
+        $this->runtimeCache->set($cacheId, $isSiteRoot);
+
+        return $isSiteRoot;
+    }
+
+    /**
+     * @param $pageId
+     * @param string $fieldList
+     * @return array
+     */
+    protected function getPageRecordByPageId($pageId, $fieldList = 'is_siteroot')
+    {
+        return (array)BackendUtility::getRecord('pages', $pageId, $fieldList);
+    }
+
+    /**
+     * Determines the rootpage ID for a given page.
+     *
+     * @param int $pageId A page ID somewhere in a tree.
+     * @param bool $forceFallback Force the explicit detection and do not use the current frontend root line
+     * @param string $mountPointIdentifier
+     * @return int The page's tree branch's root page ID
+     */
+    public function getRootPageId($pageId = 0, $forceFallback = false, $mountPointIdentifier = '')
+    {
+        /** @var Rootline $rootLine */
+        $rootLine = GeneralUtility::makeInstance(Rootline::class);
+        $rootPageId = intval($pageId) ?: intval($GLOBALS['TSFE']->id);
+
+        // frontend
+        if (!empty($GLOBALS['TSFE']->rootLine)) {
+            $rootLine->setRootLineArray($GLOBALS['TSFE']->rootLine);
+        }
+
+        // fallback, backend
+        if ($pageId != 0 && ($forceFallback || !$rootLine->getHasRootPage())) {
+            $rootlineUtility = GeneralUtility::makeInstance(RootlineUtility::class, $pageId, $mountPointIdentifier);
+            try {
+                $rootLineArray = $rootlineUtility->get();
+            } catch (\RuntimeException $e) {
+                $rootLineArray = [];
+            }
+            $rootLine->setRootLineArray($rootLineArray);
+        }
+
+        $rootPageFromRootLine = $rootLine->getRootPageId();
+
+        return $rootPageFromRootLine === 0 ? $rootPageId : $rootPageFromRootLine;
+    }
+
+
+    /**
+     * This method determines the responsible site roots for a record by getting the rootPage of the record and checking
+     * if the pid is references in another site with additionalPageIds and returning those rootPageIds as well.
+     *
+     * @param string $table
+     * @param integer $uid
+     * @return array
+     */
+    protected function buildResponsibleRootPageIds($table, $uid)
+    {
+        $rootPages = [];
+        $rootPageId = $this->getRootPageIdByTableAndUid($table, $uid);
+        if ($this->getIsRootPageId($rootPageId)) {
+            $rootPages[] = $rootPageId;
+        }
+        if ($this->extensionConfiguration->getIsUseConfigurationTrackRecordsOutsideSiteroot()) {
+            $recordPageId = $this->getRecordPageId($table, $uid);
+            if ($recordPageId === 0) {
+                return $rootPages;
+            }
+            $alternativeSiteRoots = $this->getAlternativeSiteRootPagesIds($table, $uid, $recordPageId);
+            $rootPages = array_merge($rootPages, $alternativeSiteRoots);
+        }
+
+        return $rootPages;
+    }
+
+    /**
+     * This method checks if the record is a pages record or another one and determines the rootPageId from the records
+     * rootline.
+     *
+     * @param string $table
+     * @param int $uid
+     * @return int
+     */
+    protected function getRootPageIdByTableAndUid($table, $uid)
+    {
+        if ($table === 'pages') {
+            $rootPageId = $this->getRootPageId($uid);
+            return $rootPageId;
+        } else {
+            $recordPageId = $this->getRecordPageId($table, $uid);
+            $rootPageId = $this->getRootPageId($recordPageId, true);
+            return $rootPageId;
+        }
+    }
+
+    /**
+     * Returns the pageId of the record or 0 when no valid record was given.
+     *
+     * @param string $table
+     * @param integer $uid
+     * @return mixed
+     */
+    protected function getRecordPageId($table, $uid)
+    {
+        $record = BackendUtility::getRecord($table, $uid, 'pid');
+        return !empty($record['pid']) ? (int)$record['pid'] : 0;
+    }
+
+    /**
+     * When no root page can be determined we check if the pageIdOf the record is configured as additionalPageId in the index
+     * configuration of another site, if so we return the rootPageId of this site.
+     * The result is cached by the caching framework.
+     *
+     * @param string $table
+     * @param int $uid
+     * @param int $recordPageId
+     * @return array
+     */
+    public function getAlternativeSiteRootPagesIds($table, $uid, $recordPageId)
+    {
+        $siteRootsByObservedPageIds = $this->getSiteRootsByObservedPageIds($table, $uid);
+        if (!isset($siteRootsByObservedPageIds[$recordPageId])) {
+            return [];
+        }
+
+        return $siteRootsByObservedPageIds[$recordPageId];
+    }
+
+    /**
+     * Retrieves an optimized array structure we the monitored pageId as key and the relevant site rootIds as value.
+     *
+     * @param string $table
+     * @param integer $uid
+     * @return array
+     */
+    protected function getSiteRootsByObservedPageIds($table, $uid)
+    {
+        $cacheId = 'RootPageResolver' . '_' . 'getSiteRootsByObservedPageIds' . '_' . $table . '_' . $uid;
+        $methodResult = $this->runtimeCache->get($cacheId);
+        if (!empty($methodResult)) {
+            return $methodResult;
+        }
+
+        $methodResult = $this->buildSiteRootsByObservedPageIds($table, $uid);
+        $this->runtimeCache->set($cacheId, $methodResult);
+
+        return $methodResult;
+    }
+
+    /**
+     * This methods build an array with observer page id as key and rootPageIds as values to determine which root pages
+     * are responsible for this record by referencing the pageId in additionalPageIds configuration.
+     *
+     * @param string $table
+     * @param integer $uid
+     * @return array
+     */
+    protected function buildSiteRootsByObservedPageIds($table, $uid)
+    {
+        $siteRootByObservedPageIds = [];
+        $siteRepository = GeneralUtility::makeInstance(SiteRepository::class);
+        $allSites = $siteRepository->getAvailableSites();
+
+        foreach ($allSites as $site) {
+            $solrConfiguration = $site->getSolrConfiguration();
+            $indexingConfigurationName = $this->recordService->getIndexingConfigurationName($table, $uid, $solrConfiguration);
+            if ($indexingConfigurationName === null) {
+                continue;
+            }
+            $observedPageIdsOfSiteRoot = $solrConfiguration->getIndexQueueAdditionalPageIdsByConfigurationName($indexingConfigurationName);
+            foreach ($observedPageIdsOfSiteRoot as $observedPageIdOfSiteRoot) {
+                $siteRootByObservedPageIds[$observedPageIdOfSiteRoot][] = $site->getRootPageId();
+            }
+        }
+
+        return $siteRootByObservedPageIds;
+    }
+}

Classes/Domain/Index/Queue/Statistic/QueueStatistic.php

@@ -0,0 +1,138 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\Statistic;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+class QueueStatistic
+{
+
+    /**
+     * @var int
+     */
+    protected $failedCount = 0;
+
+    /**
+     * @var int
+     */
+    protected $pendingCount = 0;
+
+    /**
+     * @var int
+     */
+    protected $successCount = 0;
+
+    /**
+     * @param int $failedCount
+     */
+    public function setFailedCount($failedCount)
+    {
+        $this->failedCount = $failedCount;
+    }
+
+    /**
+     * @return int
+     */
+    public function getFailedCount()
+    {
+        return $this->failedCount;
+    }
+
+    /**
+     * @return float|int
+     */
+    public function getFailedPercentage()
+    {
+        return $this->getPercentage($this->getFailedCount());
+    }
+
+    /**
+     * @param int $pendingCount
+     */
+    public function setPendingCount($pendingCount)
+    {
+        $this->pendingCount = $pendingCount;
+    }
+
+    /**
+     * @return int
+     */
+    public function getPendingCount()
+    {
+        return $this->pendingCount;
+    }
+
+    /**
+     * @return float|int
+     */
+    public function getPendingPercentage()
+    {
+        return $this->getPercentage($this->getPendingCount());
+    }
+
+    /**
+     * @param int $successCount
+     */
+    public function setSuccessCount($successCount)
+    {
+        $this->successCount = $successCount;
+    }
+
+    /**
+     * @return int
+     */
+    public function getSuccessCount()
+    {
+        return $this->successCount;
+    }
+
+    /**
+     * @return float|int
+     */
+    public function getSuccessPercentage()
+    {
+        return $this->getPercentage($this->getSuccessCount());
+    }
+
+    /**
+     * @return int
+     */
+    public function getTotalCount()
+    {
+        return $this->pendingCount + $this->failedCount + $this->successCount;
+    }
+
+    /**
+     * @param integer $count
+     * @return float
+     */
+    protected function getPercentage($count)
+    {
+        $total = $this->getTotalCount();
+        if ($total === 0) {
+            return 0.0;
+        }
+        return (float)round((100 / $total) * $count, 2);
+    }
+}

Classes/Domain/Index/Queue/Statistic/QueueStatisticsRepository.php

@@ -0,0 +1,108 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Index\Queue\Statistic;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Records\AbstractRepository;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Persistence\Generic\Exception\UnsupportedMethodException;
+
+/**
+ * Class QueueStatisticsRepository
+ */
+class QueueStatisticsRepository extends AbstractRepository
+{
+    /**
+     * @var string
+     */
+    protected $table = 'tx_meilisearch_indexqueue_item';
+
+    /**
+     * Extracts the number of pending, indexed and erroneous items from the
+     * Index Queue.
+     *
+     * @param int $rootPid
+     * @param string $indexingConfigurationName
+     *
+     * @return QueueStatistic
+     */
+    public function findOneByRootPidAndOptionalIndexingConfigurationName(int $rootPid, $indexingConfigurationName = null): QueueStatistic
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        $queryBuilder
+            ->add('select', vsprintf('(%s < %s) AS %s', [
+                $queryBuilder->quoteIdentifier('indexed'),
+                $queryBuilder->quoteIdentifier('changed'),
+                $queryBuilder->quoteIdentifier('pending')
+            ]), true)
+            ->add('select', vsprintf('(%s) AS %s', [
+                $queryBuilder->expr()->notLike('errors', $queryBuilder->createNamedParameter('')),
+                $queryBuilder->quoteIdentifier('failed')
+            ]), true)
+            ->add('select', $queryBuilder->expr()->count('*', 'count'), true)
+            ->from($this->table)
+            ->where($queryBuilder->expr()->eq('root', $queryBuilder->createNamedParameter($rootPid, \PDO::PARAM_INT)))
+            ->groupBy('pending', 'failed');
+
+        if (!empty($indexingConfigurationName)) {
+            $queryBuilder->andWhere($queryBuilder->expr()->eq('indexing_configuration', $queryBuilder->createNamedParameter($indexingConfigurationName)));
+        }
+
+        return $this->buildQueueStatisticFromResultSet($queryBuilder->execute()->fetchAll());
+    }
+
+    /**
+     * Instantiates and fills QueueStatistic with values
+     *
+     * @param array $indexQueueStatisticResultSet
+     * @return QueueStatistic
+     */
+    protected function buildQueueStatisticFromResultSet(array $indexQueueStatisticResultSet): QueueStatistic
+    {
+        /* @var $statistic QueueStatistic */
+        $statistic = GeneralUtility::makeInstance(QueueStatistic::class);
+        foreach ($indexQueueStatisticResultSet as $row) {
+            if ($row['failed'] == 1) {
+                $statistic->setFailedCount((int)$row['count']);
+            } elseif ($row['pending'] == 1) {
+                $statistic->setPendingCount((int)$row['count']);
+            } else {
+                $statistic->setSuccessCount((int)$row['count']);
+            }
+        }
+
+        return $statistic;
+    }
+
+    /**
+     * Don't use this method.
+     *
+     * @return int
+     * @throws UnsupportedMethodException
+     */
+    public function count(): int
+    {
+        throw new UnsupportedMethodException('Can not count the Index Queue Statistics.', 1504694750);
+    }
+}

Classes/Domain/Search/ApacheSolrDocument/Builder.php

@@ -0,0 +1,312 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ApacheSolrDocument;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Access\Rootline;
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\Domain\Variants\IdBuilder;
+use WapplerSystems\Meilisearch\Domain\Site\Site;
+use WapplerSystems\Meilisearch\System\Solr\Document\Document;
+use WapplerSystems\Meilisearch\Typo3PageContentExtractor;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
+
+/**
+ * Builder class to build an ApacheSolrDocument
+ *
+ * Responsible to build \WapplerSystems\Meilisearch\System\Solr\Document\Document
+ *
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class Builder
+{
+    /**
+     * @var IdBuilder
+     */
+    protected $variantIdBuilder;
+
+    /**
+     * Builder constructor.
+     * @param IdBuilder|null $variantIdBuilder
+     */
+    public function __construct(IdBuilder $variantIdBuilder = null)
+    {
+        $this->variantIdBuilder = $variantIdBuilder ?? GeneralUtility::makeInstance(IdBuilder::class);
+    }
+
+    /**
+     * This method can be used to build an Document from a TYPO3 page.
+     *
+     * @param TypoScriptFrontendController $page
+     * @param string $url
+     * @param Rootline $pageAccessRootline
+     * @param string $mountPointParameter
+     * @return Document|object
+     */
+    public function fromPage(TypoScriptFrontendController $page, $url, Rootline $pageAccessRootline, $mountPointParameter): Document
+    {
+        /* @var $document Document */
+        $document = GeneralUtility::makeInstance(Document::class);
+        $site = $this->getSiteByPageId($page->id);
+        $pageRecord = $page->page;
+
+        $accessGroups = $this->getDocumentIdGroups($pageAccessRootline);
+        $documentId = $this->getPageDocumentId($page, $accessGroups, $mountPointParameter);
+
+        $document->setField('id', $documentId);
+        $document->setField('site', $site->getDomain());
+        $document->setField('siteHash', $site->getSiteHash());
+        $document->setField('appKey', 'EXT:meilisearch');
+        $document->setField('type', 'pages');
+
+        // system fields
+        $document->setField('uid', $page->id);
+        $document->setField('pid', $pageRecord['pid']);
+
+        // variantId
+        $variantId = $this->variantIdBuilder->buildFromTypeAndUid('pages', $page->id);
+        $document->setField('variantId', $variantId);
+
+        $document->setField('typeNum', $page->type);
+        $document->setField('created', $pageRecord['crdate']);
+        $document->setField('changed', $pageRecord['SYS_LASTCHANGED']);
+
+        $rootline = $this->getRootLineFieldValue($page->id, $mountPointParameter);
+        $document->setField('rootline', $rootline);
+
+        // access
+        $this->addAccessField($document, $pageAccessRootline);
+        $this->addEndtimeField($document, $pageRecord);
+
+        // content
+        // @extensionScannerIgnoreLine
+        $contentExtractor = $this->getExtractorForPageContent($page->content);
+        $document->setField('title', $contentExtractor->getPageTitle());
+        $document->setField('subTitle', $pageRecord['subtitle']);
+        $document->setField('navTitle', $pageRecord['nav_title']);
+        $document->setField('author', $pageRecord['author']);
+        $document->setField('description', $pageRecord['description']);
+        $document->setField('abstract', $pageRecord['abstract']);
+        $document->setField('content', $contentExtractor->getIndexableContent());
+        $document->setField('url', $url);
+
+        $this->addKeywordsField($document, $pageRecord);
+        $this->addTagContentFields($document, $contentExtractor->getTagContent());
+
+        return $document;
+    }
+
+
+    /**
+     * Creates a Solr document with the basic / core fields set already.
+     *
+     * @param array $itemRecord
+     * @param string $type
+     * @param int $rootPageUid
+     * @param string $accessRootLine
+     * @return Document
+     */
+    public function fromRecord(array $itemRecord, string $type, int $rootPageUid, string $accessRootLine): Document
+    {
+        /* @var $document Document */
+        $document = GeneralUtility::makeInstance(Document::class);
+
+        $site = $this->getSiteByPageId($rootPageUid);
+
+        $documentId = $this->getDocumentId($type, $site->getRootPageId(), $itemRecord['uid']);
+
+        // required fields
+        $document->setField('id', $documentId);
+        $document->setField('type', $type);
+        $document->setField('appKey', 'EXT:meilisearch');
+
+        // site, siteHash
+        $document->setField('site', $site->getDomain());
+        $document->setField('siteHash', $site->getSiteHash());
+
+        // uid, pid
+        $document->setField('uid', $itemRecord['uid']);
+        $document->setField('pid', $itemRecord['pid']);
+
+        // variantId
+        $variantId = $this->variantIdBuilder->buildFromTypeAndUid($type, $itemRecord['uid']);
+        $document->setField('variantId', $variantId);
+
+        // created, changed
+        if (!empty($GLOBALS['TCA'][$type]['ctrl']['crdate'])) {
+            $document->setField('created', $itemRecord[$GLOBALS['TCA'][$type]['ctrl']['crdate']]);
+        }
+        if (!empty($GLOBALS['TCA'][$type]['ctrl']['tstamp'])) {
+            $document->setField('changed', $itemRecord[$GLOBALS['TCA'][$type]['ctrl']['tstamp']]);
+        }
+
+        // access, endtime
+        $document->setField('access', $accessRootLine);
+        if (!empty($GLOBALS['TCA'][$type]['ctrl']['enablecolumns']['endtime'])
+            && $itemRecord[$GLOBALS['TCA'][$type]['ctrl']['enablecolumns']['endtime']] != 0
+        ) {
+            $document->setField('endtime', $itemRecord[$GLOBALS['TCA'][$type]['ctrl']['enablecolumns']['endtime']]);
+        }
+
+        return $document;
+    }
+
+    /**
+     * @param TypoScriptFrontendController  $page
+     * @param string $accessGroups
+     * @param string $mountPointParameter
+     * @return string
+     */
+    protected function getPageDocumentId(TypoScriptFrontendController $frontendController, string $accessGroups, string $mountPointParameter): string
+    {
+        return Util::getPageDocumentId($frontendController->id, $frontendController->type, Util::getLanguageUid(), $accessGroups, $mountPointParameter);
+    }
+
+    /**
+     * @param string $type
+     * @param int $rootPageId
+     * @param int $recordUid
+     * @return string
+     */
+    protected function getDocumentId(string $type, int $rootPageId, int $recordUid): string
+    {
+        return Util::getDocumentId($type, $rootPageId, $recordUid);
+    }
+
+    /**
+     * @param integer $pageId
+     * @return Site
+     */
+    protected function getSiteByPageId($pageId)
+    {
+        $siteRepository = GeneralUtility::makeInstance(SiteRepository::class);
+        return $siteRepository->getSiteByPageId($pageId);
+    }
+
+    /**
+     * @param string $pageContent
+     * @return Typo3PageContentExtractor
+     */
+    protected function getExtractorForPageContent($pageContent)
+    {
+        return GeneralUtility::makeInstance(Typo3PageContentExtractor::class, /** @scrutinizer ignore-type */ $pageContent);
+    }
+
+    /**
+     * Builds the content for the rootline field.
+     *
+     * @param int $pageId
+     * @param string $mountPointParameter
+     * @return string
+     */
+    protected function getRootLineFieldValue($pageId, $mountPointParameter)
+    {
+        $rootline = $pageId;
+        if ($mountPointParameter !== '') {
+            $rootline .= ',' . $mountPointParameter;
+        }
+        return $rootline;
+    }
+
+    /**
+     * Gets a comma separated list of frontend user groups to use for the
+     * document ID.
+     *
+     * @param Rootline $pageAccessRootline
+     * @return string A comma separated list of frontend user groups.
+     */
+    protected function getDocumentIdGroups(Rootline $pageAccessRootline)
+    {
+        $groups = $pageAccessRootline->getGroups();
+        $groups = Rootline::cleanGroupArray($groups);
+
+        if (empty($groups)) {
+            $groups[] = 0;
+        }
+
+        $groups = implode(',', $groups);
+
+        return $groups;
+    }
+
+    /**
+     * Adds the access field to the document if needed.
+     *
+     * @param Document $document
+     * @param Rootline $pageAccessRootline
+     */
+    protected function addAccessField(Document $document, Rootline $pageAccessRootline)
+    {
+        $access = (string)$pageAccessRootline;
+        if (trim($access) !== '') {
+            $document->setField('access', $access);
+        }
+    }
+
+    /**
+     * Adds the endtime field value to the Document.
+     *
+     * @param Document $document
+     * @param array $pageRecord
+     */
+    protected function addEndtimeField(Document $document, $pageRecord)
+    {
+        if ($pageRecord['endtime']) {
+            $document->setField('endtime', $pageRecord['endtime']);
+        }
+    }
+
+    /**
+     * Adds keywords, multi valued.
+     *
+     * @param Document $document
+     * @param array $pageRecord
+     */
+    protected function addKeywordsField(Document $document, $pageRecord)
+    {
+        if (!isset($pageRecord['keywords'])) {
+            return;
+        }
+
+        $keywords = array_unique(GeneralUtility::trimExplode(',', $pageRecord['keywords'], true));
+        foreach ($keywords as $keyword) {
+            $document->addField('keywords', $keyword);
+        }
+    }
+
+    /**
+     * Add content from several tags like headers, anchors, ...
+     *
+     * @param Document $document
+     * @param array $tagContent
+     */
+    protected function addTagContentFields(Document  $document, $tagContent = [])
+    {
+        foreach ($tagContent as $fieldName => $fieldValue) {
+            $document->setField($fieldName, $fieldValue);
+        }
+    }
+}

Classes/Domain/Search/ApacheSolrDocument/Repository.php

@@ -0,0 +1,170 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ApacheSolrDocument;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Rafael Kähm <rafael.kaehm@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\ConnectionManager;
+use WapplerSystems\Meilisearch\Domain\Search\Query\QueryBuilder;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Result\Parser\DocumentEscapeService;
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\NoSolrConnectionFoundException;
+use WapplerSystems\Meilisearch\Search;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\System\Solr\Document\Document;
+use WapplerSystems\Meilisearch\System\Solr\SolrCommunicationException;
+use WapplerSystems\Meilisearch\System\Solr\SolrConnection;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Core\SingletonInterface;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Class Repository
+ */
+class Repository implements SingletonInterface
+{
+
+    /**
+     * Search
+     *
+     * @var \WapplerSystems\Meilisearch\Search
+     */
+    protected $search;
+
+    /**
+     * @var DocumentEscapeService
+     */
+    protected $documentEscapeService = null;
+
+    /**
+     * @var TypoScriptConfiguration|null
+     */
+    protected $typoScriptConfiguration = null;
+
+    /**
+     * @var QueryBuilder
+     */
+    protected $queryBuilder;
+
+    /**
+     * Repository constructor.
+     * @param DocumentEscapeService|null $documentEscapeService
+     * @param QueryBuilder|null $queryBuilder
+     */
+    public function __construct(DocumentEscapeService $documentEscapeService = null, TypoScriptConfiguration $typoScriptConfiguration = null, QueryBuilder $queryBuilder = null)
+    {
+        $this->typoScriptConfiguration = $typoScriptConfiguration ?? Util::getSolrConfiguration();
+        $this->documentEscapeService = $documentEscapeService ?? GeneralUtility::makeInstance(DocumentEscapeService::class, /** @scrutinizer ignore-type */ $typoScriptConfiguration);
+        $this->queryBuilder = $queryBuilder ?? GeneralUtility::makeInstance(QueryBuilder::class, /** @scrutinizer ignore-type */ $this->typoScriptConfiguration);
+    }
+
+    /**
+     * Returns firs found \WapplerSystems\Meilisearch\System\Solr\Document\Document for current page by given language id.
+     *
+     * @param $languageId
+     * @return Document|false
+     */
+    public function findOneByPageIdAndByLanguageId($pageId, $languageId)
+    {
+        $documentCollection = $this->findByPageIdAndByLanguageId($pageId, $languageId);
+        return reset($documentCollection);
+    }
+
+    /**
+     * Returns all found \WapplerSystems\Meilisearch\System\Solr\Document\Document[] by given page id and language id.
+     * Returns empty array if nothing found, e.g. if no language or no page(or no index for page) is present.
+     *
+     * @param int $pageId
+     * @param int $languageId
+     * @return Document[]
+     */
+    public function findByPageIdAndByLanguageId($pageId, $languageId)
+    {
+        try {
+            $this->initializeSearch($pageId, $languageId);
+            $pageQuery = $this->queryBuilder->buildPageQuery($pageId);
+            $response = $this->search->search($pageQuery, 0, 10000);
+        } catch (NoSolrConnectionFoundException $exception) {
+            return [];
+        } catch (SolrCommunicationException $exception) {
+            return [];
+        }
+        $data = $response->getParsedData();
+        // @extensionScannerIgnoreLine
+        return $this->documentEscapeService->applyHtmlSpecialCharsOnAllFields($data->response->docs ?? []);
+    }
+
+    /**
+     * @param string $type
+     * @param int $uid
+     * @param int $pageId
+     * @param int $languageId
+     * @return Document[]|array
+     */
+    public function findByTypeAndPidAndUidAndLanguageId($type, $uid, $pageId, $languageId): array
+    {
+        try {
+            $this->initializeSearch($pageId, $languageId);
+            $recordQuery = $this->queryBuilder->buildRecordQuery($type, $uid, $pageId);
+            $response = $this->search->search($recordQuery, 0, 10000);
+        } catch (NoSolrConnectionFoundException $exception) {
+            return [];
+        } catch (SolrCommunicationException $exception) {
+            return [];
+        }
+        $data = $response->getParsedData();
+        // @extensionScannerIgnoreLine
+        return $this->documentEscapeService->applyHtmlSpecialCharsOnAllFields($data->response->docs ?? []);
+    }
+
+    /**
+     * Initializes Search for given language
+     *
+     * @param int $languageId
+     */
+    protected function initializeSearch($pageId, $languageId = 0)
+    {
+        if (!is_int($pageId)) {
+            throw new \InvalidArgumentException('Invalid page ID = ' . $pageId, 1487332926);
+        }
+        if (!is_int($languageId)) { // @todo: Check if lang id is defined and present?
+            throw new \InvalidArgumentException('Invalid language ID = ' . $languageId, 1487335178);
+        }
+        /* @var $connectionManager ConnectionManager */
+        $connectionManager = GeneralUtility::makeInstance(ConnectionManager::class);
+        $solrConnection = $connectionManager->getConnectionByPageId($pageId, $languageId);
+
+        $this->search = $this->getSearch($solrConnection);
+    }
+
+    /**
+     * Retrieves an instance of the Search object.
+     *
+     * @param SolrConnection $solrConnection
+     * @return Search
+     */
+    protected function getSearch($solrConnection)
+    {
+        return  GeneralUtility::makeInstance(Search::class, /** @scrutinizer ignore-type */ $solrConnection);
+    }
+}

Classes/Domain/Search/FrequentSearches/FrequentSearchesService.php

@@ -0,0 +1,179 @@
+<?php declare(strict_types = 1);
+namespace WapplerSystems\Meilisearch\Domain\Search\FrequentSearches;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\Statistics\StatisticsRepository;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Core\Cache\Frontend\AbstractFrontend;
+use TYPO3\CMS\Core\Cache\Frontend\FrontendInterface;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
+
+/**
+ * The FrequentSearchesService is used to retrieve the frequent searches from the database or cache.
+ *
+ * @author Dimitri Ebert <dimitri.ebert@dkd.de>
+ * @author Timo Schmidt <timo.schmidt@dkd.de>
+ * @copyright (c) 2015-2021 dkd Internet Service GmbH <info@dkd.de>
+ */
+class FrequentSearchesService
+{
+
+    /**
+     * Instance of the caching frontend used to cache this command's output.
+     *
+     * @var AbstractFrontend
+     */
+    protected $cache;
+
+    /**
+     * @var TypoScriptFrontendController
+     */
+    protected $tsfe;
+
+    /**
+     * @var StatisticsRepository
+     */
+    protected $statisticsRepository;
+
+    /**
+     * @var TypoScriptConfiguration
+     */
+    protected $configuration;
+
+    /**
+     * @param TypoScriptConfiguration $typoscriptConfiguration
+     * @param AbstractFrontend|null $cache
+     * @param TypoScriptFrontendController|null $tsfe
+     * @param StatisticsRepository|null $statisticsRepository
+     */
+    public function __construct(
+        TypoScriptConfiguration $typoscriptConfiguration,
+        AbstractFrontend $cache = null,
+        TypoScriptFrontendController $tsfe = null,
+        StatisticsRepository $statisticsRepository = null
+    ) {
+        $this->configuration = $typoscriptConfiguration;
+        $this->cache = $cache;
+        $this->tsfe = $tsfe;
+        $this->statisticsRepository = $statisticsRepository ?? GeneralUtility::makeInstance(StatisticsRepository::class);
+    }
+
+    /**
+     * Generates an array with terms and hits
+     *
+     * @return array Tags as array with terms and hits
+     */
+    public function getFrequentSearchTerms() : array
+    {
+        $frequentSearchConfiguration = $this->configuration->getSearchFrequentSearchesConfiguration();
+
+        $identifier = $this->getCacheIdentifier($frequentSearchConfiguration);
+
+        if ($this->hasValidCache() && $this->cache->has($identifier)) {
+            $terms = $this->cache->get($identifier);
+        } else {
+            $terms = $this->getFrequentSearchTermsFromStatistics($frequentSearchConfiguration);
+
+            if ($frequentSearchConfiguration['sortBy'] === 'hits') {
+                arsort($terms);
+            } else {
+                ksort($terms);
+            }
+
+            $lifetime = null;
+            if (isset($frequentSearchConfiguration['cacheLifetime'])) {
+                $lifetime = intval($frequentSearchConfiguration['cacheLifetime']);
+            }
+
+            if ($this->hasValidCache()) {
+                $this->cache->set($identifier, $terms, [], $lifetime);
+            }
+        }
+
+        return $terms;
+    }
+
+    /**
+     * Gets frequent search terms from the statistics tracking table.
+     *
+     * @param array $frequentSearchConfiguration
+     * @return array Array of frequent search terms, keys are the terms, values are hits
+     */
+    protected function getFrequentSearchTermsFromStatistics(array $frequentSearchConfiguration) : array
+    {
+        $terms = [];
+
+        if ($frequentSearchConfiguration['select.']['checkRootPageId']) {
+            $checkRootPidWhere = 'root_pid = ' . $this->tsfe->tmpl->rootLine[0]['uid'];
+        } else {
+            $checkRootPidWhere = '1';
+        }
+        if ($frequentSearchConfiguration['select.']['checkLanguage']) {
+            $checkLanguageWhere = ' AND language =' . Util::getLanguageUid();
+        } else {
+            $checkLanguageWhere = '';
+        }
+
+        $frequentSearchConfiguration['select.']['ADD_WHERE'] = $checkRootPidWhere .
+            $checkLanguageWhere . ' ' .
+            $frequentSearchConfiguration['select.']['ADD_WHERE'];
+
+        $frequentSearchTerms = $this->statisticsRepository
+            ->getFrequentSearchTermsFromStatisticsByFrequentSearchConfiguration($frequentSearchConfiguration);
+
+        if (!is_array($frequentSearchTerms)) {
+            return $terms;
+        }
+
+        foreach ($frequentSearchTerms as $term) {
+            $cleanedTerm = html_entity_decode($term['search_term'], ENT_QUOTES, 'UTF-8');
+            $terms[$cleanedTerm] = $term['hits'];
+        }
+
+        return $terms;
+    }
+
+    /**
+     * @param array $frequentSearchConfiguration
+     * @return string
+     */
+    protected function getCacheIdentifier(array $frequentSearchConfiguration) : string
+    {
+        // Use configuration as cache identifier
+        $identifier = 'frequentSearchesTags';
+
+        if ($frequentSearchConfiguration['select.']['checkRootPageId']) {
+            $identifier .= '_RP' . (int)$this->tsfe->tmpl->rootLine[0]['uid'];
+        }
+        if ($frequentSearchConfiguration['select.']['checkLanguage']) {
+            $identifier .= '_L' . Util::getLanguageUid();
+        }
+
+        $identifier .= '_' . md5(serialize($frequentSearchConfiguration));
+        return $identifier;
+    }
+
+    /**
+     * Checks if this service has a valid cache class
+     *
+     * @return bool
+     */
+    protected function hasValidCache(): bool
+    {
+        return ($this->cache instanceof FrontendInterface);
+    }
+}

Classes/Domain/Search/Highlight/SiteHighlighterUrlModifier.php

@@ -0,0 +1,60 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Highlight;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+
+
+/**
+ * Provides highlighting of the search words on the document's actual page by
+ * adding parameters to a document's URL property.
+ *
+ * Initial code from WapplerSystems\Meilisearch\ResultDocumentModifier\SiteHighlighter
+ *
+ * @author Stefan Sprenger <stefan.sprenger@dkd.de>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+
+use WapplerSystems\Meilisearch\System\Url\UrlHelper;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Class SiteHighlighterUrlModifier
+ */
+class SiteHighlighterUrlModifier {
+
+    /**
+     * @param string $url
+     * @param string $searchWords
+     * @param boolean $addNoCache
+     * @param boolean $keepCHash
+     * @return string
+     */
+    public function modify($url, $searchWords, $addNoCache = true, $keepCHash = false) {
+        $searchWords = str_replace('&quot;', '', $searchWords);
+        $searchWords = GeneralUtility::trimExplode(' ', $searchWords, true);
+
+            /** @var UrlHelper $urlHelper */
+        $urlHelper = GeneralUtility::makeInstance(UrlHelper::class, /** @scrutinizer ignore-type */ $url);
+        $urlHelper->addQueryParameter('sword_list', $searchWords);
+
+        if ($addNoCache) {
+            $urlHelper->addQueryParameter('no_cache', '1');
+        }
+
+        if (!$keepCHash) {
+            $urlHelper->removeQueryParameter('cHash');
+        }
+
+        return $urlHelper->getUrl();
+    }
+}

Classes/Domain/Search/LastSearches/LastSearchesRepository.php

@@ -0,0 +1,156 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\LastSearches;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Records\AbstractRepository;
+
+class LastSearchesRepository extends AbstractRepository
+{
+    /**
+     * @var string
+     */
+    protected $table = 'tx_meilisearch_last_searches';
+
+    /**
+     * Finds the last searched keywords from the database
+     *
+     * @param int $limit
+     * @return array An array containing the last searches of the current user
+     */
+    public function findAllKeywords($limit = 10) : array
+    {
+        $lastSearchesResultSet = $this->getLastSearchesResultSet($limit);
+        if (empty($lastSearchesResultSet)) {
+            return [];
+        }
+
+        $lastSearches = [];
+        foreach ($lastSearchesResultSet as $row) {
+            $lastSearches[] = html_entity_decode($row['keywords'], ENT_QUOTES, 'UTF-8');
+        }
+
+        return $lastSearches;
+    }
+
+    /**
+     * Returns all last searches
+     *
+     * @param $limit
+     * @return array
+     */
+    protected function getLastSearchesResultSet($limit) : array
+    {
+        $queryBuilder = $this->getQueryBuilder();
+        return $queryBuilder
+            ->select('keywords')
+            ->addSelectLiteral(
+                $queryBuilder->expr()->max('tstamp','maxtstamp')
+            )
+            ->from($this->table)
+            // There is no support for DISTINCT, a ->groupBy() has to be used instead.
+            ->groupBy('keywords')
+            ->orderBy('maxtstamp', 'DESC')
+            ->setMaxResults($limit)->execute()->fetchAll();
+    }
+
+    /**
+     * Adds keywords to last searches or updates the oldest row by given limit.
+     *
+     * @param string $lastSearchesKeywords
+     * @param int $lastSearchesLimit
+     * @return void
+     */
+    public function add(string $lastSearchesKeywords, int $lastSearchesLimit)
+    {
+        $nextSequenceId = $this->resolveNextSequenceIdForGivenLimit($lastSearchesLimit);
+        $rowsCount = $this->count();
+        if ($nextSequenceId < $rowsCount) {
+            $this->update([
+                'sequence_id' => $nextSequenceId,
+                'keywords' => $lastSearchesKeywords
+            ]);
+            return;
+        }
+
+        $queryBuilder = $this->getQueryBuilder();
+        $queryBuilder
+            ->insert($this->table)
+            ->values([
+                'sequence_id' => $nextSequenceId,
+                'keywords' => $lastSearchesKeywords,
+                'tstamp' => time()
+            ])
+            ->execute();
+    }
+
+    /**
+     * Resolves next sequence id by given last searches limit.
+     *
+     * @param int $lastSearchesLimit
+     * @return int
+     */
+    protected function resolveNextSequenceIdForGivenLimit(int $lastSearchesLimit) : int
+    {
+        $nextSequenceId = 0;
+
+        $queryBuilder = $this->getQueryBuilder();
+        $result = $queryBuilder->select('sequence_id')
+            ->from($this->table)
+            ->orderBy('tstamp', 'DESC')
+            ->setMaxResults(1)
+            ->execute()->fetch();
+
+        if (!empty($result)) {
+            $nextSequenceId = ($result['sequence_id'] + 1) % $lastSearchesLimit;
+        }
+
+        return $nextSequenceId;
+    }
+
+    /**
+     * Updates last searches row by using sequence_id from given $lastSearchesRow array
+     *
+     * @param array $lastSearchesRow
+     * @return void
+     * @throws \InvalidArgumentException
+     */
+    protected function update(array $lastSearchesRow)
+    {
+        $queryBuilder = $this->getQueryBuilder();
+
+        $affectedRows = $queryBuilder
+            ->update($this->table)
+            ->where(
+                $queryBuilder->expr()->eq('sequence_id', $queryBuilder->createNamedParameter($lastSearchesRow['sequence_id']))
+            )
+            ->set('tstamp', time())
+            ->set('keywords', $lastSearchesRow['keywords'])
+            ->execute();
+
+        if ($affectedRows < 1) {
+            throw new \InvalidArgumentException(vsprintf('By trying to update last searches row with values "%s" nothing was updated, make sure the given "sequence_id" exists in database.', [\json_encode($lastSearchesRow)]), 1502717923);
+        }
+    }
+}

Classes/Domain/Search/LastSearches/LastSearchesService.php

@@ -0,0 +1,148 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\LastSearches;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2015-2016 Timo Schmidt <timo.schmidt@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\System\Session\FrontendUserSession;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The LastSearchesService is responsible to return the LastSearches from the session or database,
+ * depending on the configuration.
+ *
+ * @author Timo Schmidt <timo.schmidt@dkd.de>
+ */
+class LastSearchesService
+{
+
+    /**
+     * @var TypoScriptConfiguration
+     */
+    protected $configuration;
+
+    /**
+     * @var FrontendUserSession
+     */
+    protected $session;
+
+    /**
+     * @var LastSearchesRepository
+     */
+    protected $lastSearchesRepository;
+
+    /**
+     * @param TypoScriptConfiguration $typoscriptConfiguration
+     * @param FrontendUserSession|null $session
+     * @param LastSearchesRepository|null $lastSearchesRepository
+     */
+    public function __construct(TypoScriptConfiguration $typoscriptConfiguration, FrontendUserSession $session = null, LastSearchesRepository $lastSearchesRepository = null)
+    {
+        $this->configuration = $typoscriptConfiguration;
+        $this->session = $session ?? GeneralUtility::makeInstance(FrontendUserSession::class);
+        $this->lastSearchesRepository = $lastSearchesRepository ?? GeneralUtility::makeInstance(LastSearchesRepository::class);
+    }
+
+    /**
+     * Retrieves the last searches from the session or database depending on the configuration.
+     *
+     * @return array
+     */
+    public function getLastSearches()
+    {
+        $lastSearchesKeywords = [];
+        $mode   = $this->configuration->getSearchLastSearchesMode();
+        $limit  = $this->configuration->getSearchLastSearchesLimit();
+
+        switch ($mode) {
+            case 'user':
+                $lastSearchesKeywords = $this->getLastSearchesFromSession($limit);
+                break;
+            case 'global':
+                $lastSearchesKeywords = $this->lastSearchesRepository->findAllKeywords($limit);
+                break;
+        }
+
+        return $lastSearchesKeywords;
+    }
+
+    /**
+     * Saves the keywords to the last searches in the database or session depending on the configuration.
+     *
+     * @param string $keywords
+     * @throws \UnexpectedValueException
+     */
+    public function addToLastSearches($keywords)
+    {
+        $mode = $this->configuration->getSearchLastSearchesMode();
+        switch ($mode) {
+            case 'user':
+                $this->storeKeywordsToSession($keywords);
+                break;
+            case 'global':
+                $this->lastSearchesRepository->add($keywords, (int)$this->configuration->getSearchLastSearchesLimit());
+                break;
+            default:
+                throw new \UnexpectedValueException(
+                    'Unknown mode for plugin.tx_meilisearch.search.lastSearches.mode, valid modes are "user" or "global".',
+                    1342456570
+                );
+        }
+    }
+
+    /**
+     * Gets the last searched keywords from the user's session
+     *
+     * @param int $limit
+     * @return array An array containing the last searches of the current user
+     */
+    protected function getLastSearchesFromSession($limit)
+    {
+        $lastSearches = $this->session->getLastSearches();
+        $lastSearches = array_slice(array_reverse(array_unique($lastSearches)), 0, $limit);
+
+        return $lastSearches;
+    }
+
+    /**
+     * Stores the keywords from the current query to the user's session.
+     *
+     * @param string $keywords The current query's keywords
+     * @return void
+     */
+    protected function storeKeywordsToSession($keywords)
+    {
+        $currentLastSearches = $this->session->getLastSearches();
+        $lastSearches = $currentLastSearches;
+        $newLastSearchesCount = array_push($lastSearches, $keywords);
+
+        while ($newLastSearchesCount > $this->configuration->getSearchLastSearchesLimit()) {
+            array_shift($lastSearches);
+            $newLastSearchesCount = count($lastSearches);
+        }
+
+        $this->session->setLastSearches($lastSearches);
+    }
+}

Classes/Domain/Search/LastSearches/LastSearchesWriterProcessor.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\LastSearches;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\LastSearches\LastSearchesService;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSetProcessor;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Writes the last searches
+ *
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class LastSearchesWriterProcessor implements SearchResultSetProcessor
+{
+
+    /**
+     * @param SearchResultSet $resultSet
+     * @return SearchResultSet
+     */
+    public function process(SearchResultSet $resultSet) {
+
+        if ($resultSet->getAllResultCount() === 0) {
+            // when the search does not produce a result we do not store the last searches
+            return $resultSet;
+        }
+
+        if (!isset($GLOBALS['TSFE'])) {
+            return $resultSet;
+        }
+
+        $query = $resultSet->getUsedSearchRequest()->getRawUserQuery();
+
+        if (is_string($query)) {
+            $lastSearchesService = $this->getLastSearchesService($resultSet);
+            $lastSearchesService->addToLastSearches($query);
+        }
+
+        return $resultSet;
+    }
+
+    /**
+     * @param SearchResultSet $resultSet
+     * @return LastSearchesService
+     */
+    protected function getLastSearchesService(SearchResultSet $resultSet) {
+        return GeneralUtility::makeInstance(LastSearchesService::class,
+            /** @scrutinizer ignore-type */ $resultSet->getUsedSearchRequest()->getContextTypoScriptConfiguration());
+    }
+}

Classes/Domain/Search/Query/AbstractQueryBuilder.php

@@ -0,0 +1,558 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\Query;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\BigramPhraseFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Elevation;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Faceting;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\FieldCollapsing;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Grouping;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Highlighting;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Operator;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\PhraseFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\QueryFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\ReturnFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Slops;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Sorting;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Sortings;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Spellchecking;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\TrigramPhraseFields;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
+
+/**
+ * The AbstractQueryBuilder contains all logic to initialize solr queries independent from TYPO3.
+ */
+abstract class AbstractQueryBuilder {
+
+    /**
+     * @var Query
+     */
+    protected $queryToBuild = null;
+
+    /**
+     * @param Query $query
+     * @return $this
+     */
+    public function startFrom(Query $query)
+    {
+        $this->queryToBuild = $query;
+        return $this;
+    }
+
+    /**
+     * @return Query
+     */
+    public function getQuery(): Query
+    {
+        return $this->queryToBuild;
+    }
+
+    /**
+     * @param bool $omitHeader
+     * @return $this
+     */
+    public function useOmitHeader($omitHeader = true)
+    {
+        $this->queryToBuild->setOmitHeader($omitHeader);
+
+        return $this;
+    }
+
+    /**
+     * Uses an array of filters and applies them to the query.
+     *
+     * @param array $filterArray
+     * @return $this
+     */
+    public function useFilterArray(array $filterArray)
+    {
+        foreach ($filterArray as $key => $additionalFilter) {
+            $this->useFilter($additionalFilter, $key);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Applies the queryString that is used to search
+     *
+     * @param string $queryString
+     * @return $this
+     */
+    public function useQueryString($queryString)
+    {
+        $this->queryToBuild->setQuery($queryString);
+        return $this;
+    }
+
+    /**
+     * Applies the passed queryType to the query.
+     *
+     * @param string $queryType
+     * @return $this
+     */
+    public function useQueryType(string $queryType)
+    {
+        $this->queryToBuild->addParam('qt', $queryType);
+        return $this;
+    }
+
+    /**
+     * Remove the queryType (qt) from the query.
+     *
+     * @return $this
+     */
+    public function removeQueryType()
+    {
+        $this->queryToBuild->addParam('qt', null);
+        return $this;
+    }
+
+    /**
+     * Can be used to remove all sortings from the query.
+     *
+     * @return $this
+     */
+    public function removeAllSortings()
+    {
+        $this->queryToBuild->clearSorts();
+        return $this;
+    }
+
+    /**
+     * Applies the passed sorting to the query.
+     *
+     * @param Sorting $sorting
+     * @return $this
+     */
+    public function useSorting(Sorting $sorting)
+    {
+        if (strpos($sorting->getFieldName(), 'relevance') !== false) {
+            $this->removeAllSortings();
+            return $this;
+        }
+
+        $this->queryToBuild->addSort($sorting->getFieldName(), $sorting->getDirection());
+        return $this;
+    }
+
+    /**
+     * Applies the passed sorting to the query.
+     *
+     * @param Sortings $sortings
+     * @return $this
+     */
+    public function useSortings(Sortings $sortings)
+    {
+        foreach($sortings->getSortings() as $sorting) {
+            $this->useSorting($sorting);
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param int $resultsPerPage
+     * @return $this
+     */
+    public function useResultsPerPage($resultsPerPage)
+    {
+        $this->queryToBuild->setRows($resultsPerPage);
+        return $this;
+    }
+
+    /**
+     * @param int $page
+     * @return $this
+     */
+    public function usePage($page)
+    {
+        $this->queryToBuild->setStart($page);
+        return $this;
+    }
+
+    /**
+     * @param Operator $operator
+     * @return $this
+     */
+    public function useOperator(Operator $operator)
+    {
+        $this->queryToBuild->setQueryDefaultOperator( $operator->getOperator());
+        return $this;
+    }
+
+    /**
+     * Remove the default query operator.
+     *
+     * @return $this
+     */
+    public function removeOperator()
+    {
+        $this->queryToBuild->setQueryDefaultOperator('');
+        return $this;
+    }
+
+    /**
+     * @param Slops $slops
+     * @return $this
+     */
+    public function useSlops(Slops $slops)
+    {
+        return $slops->build($this);
+    }
+
+    /**
+     * Uses the passed boostQuer(y|ies) for the query.
+     *
+     * @param string|array $boostQueries
+     * @return $this
+     */
+    public function useBoostQueries($boostQueries)
+    {
+        $boostQueryArray = [];
+        if(is_array($boostQueries)) {
+            foreach($boostQueries as $boostQuery) {
+                $boostQueryArray[] = ['key' => md5($boostQuery), 'query' => $boostQuery];
+            }
+        } else {
+            $boostQueryArray[] = ['key' => md5($boostQueries), 'query' => $boostQueries];
+        }
+
+        $this->queryToBuild->getEDisMax()->setBoostQueries($boostQueryArray);
+        return $this;
+    }
+
+    /**
+     * Removes all boost queries from the query.
+     *
+     * @return $this
+     */
+    public function removeAllBoostQueries()
+    {
+        $this->queryToBuild->getEDisMax()->clearBoostQueries();
+        return $this;
+    }
+
+    /**
+     * Uses the passed boostFunction for the query.
+     *
+     * @param string $boostFunction
+     * @return $this
+     */
+    public function useBoostFunction(string $boostFunction)
+    {
+        $this->queryToBuild->getEDisMax()->setBoostFunctions($boostFunction);
+        return $this;
+    }
+
+    /**
+     * Removes all previously configured boost functions.
+     *
+     * @return $this
+     */
+    public function removeAllBoostFunctions()
+    {
+        $this->queryToBuild->getEDisMax()->setBoostFunctions('');
+        return $this;
+    }
+
+
+    /**
+     * Uses the passed minimumMatch(mm) for the query.
+     *
+     * @param string $minimumMatch
+     * @return $this
+     */
+    public function useMinimumMatch(string $minimumMatch)
+    {
+        $this->queryToBuild->getEDisMax()->setMinimumMatch($minimumMatch);
+        return $this;
+    }
+
+    /**
+     * Remove any previous passed minimumMatch parameter.
+     *
+     * @return $this
+     */
+    public function removeMinimumMatch()
+    {
+        $this->queryToBuild->getEDisMax()->setMinimumMatch('');
+        return $this;
+    }
+
+
+    /**
+     * Applies the tie parameter to the query.
+     *
+     * @param mixed $tie
+     * @return $this
+     */
+    public function useTieParameter($tie)
+    {
+        $this->queryToBuild->getEDisMax()->setTie($tie);
+        return $this;
+    }
+
+    /**
+     * Applies custom QueryFields to the query.
+     *
+     * @param QueryFields $queryFields
+     * @return $this
+     */
+    public function useQueryFields(QueryFields $queryFields)
+    {
+        return $queryFields->build($this);
+    }
+
+    /**
+     * Applies custom ReturnFields to the query.
+     *
+     * @param ReturnFields $returnFields
+     * @return $this
+     */
+    public function useReturnFields(ReturnFields $returnFields)
+    {
+        return $returnFields->build($this);
+    }
+
+    /**
+     * Can be used to use a specific filter string in the solr query.
+     *
+     * @param string $filterString
+     * @param string $filterName
+     * @return $this
+     */
+    public function useFilter($filterString, $filterName = '')
+    {
+        $filterName = $filterName === '' ? $filterString : $filterName;
+
+        $nameWasPassedAndFilterIsAllreadySet = $filterName !== '' && $this->queryToBuild->getFilterQuery($filterName) !== null;
+        if($nameWasPassedAndFilterIsAllreadySet) {
+            return $this;
+        }
+        $this->queryToBuild->addFilterQuery(['key' => $filterName, 'query' => $filterString]);
+        return $this;
+    }
+
+    /**
+     * Removes a filter by the fieldName.
+     *
+     * @param string $fieldName
+     * @return $this
+     */
+    public function removeFilterByFieldName($fieldName)
+    {
+        return $this->removeFilterByFunction(
+            function($key, $query) use ($fieldName) {
+                $queryString = $query->getQuery();
+                $storedFieldName = substr($queryString,0, strpos($queryString, ":"));
+                return $storedFieldName == $fieldName;
+            }
+        );
+    }
+
+    /**
+     * Removes a filter by the name of the filter (also known as key).
+     *
+     * @param string $name
+     * @return $this
+     */
+    public function removeFilterByName($name)
+    {
+        return $this->removeFilterByFunction(
+            function($key, $query) use ($name) {
+                $key = $query->getKey();
+                return $key == $name;
+            }
+        );
+    }
+
+    /**
+     * Removes a filter by the filter value.
+     *
+     * @param string $value
+     * @return $this
+     */
+    public function removeFilterByValue($value)
+    {
+        return $this->removeFilterByFunction(
+            function($key, $query) use ($value) {
+                $query = $query->getQuery();
+                return $query == $value;
+            }
+        );
+    }
+
+    /**
+     * @param \Closure $filterFunction
+     * @return $this
+     */
+    public function removeFilterByFunction($filterFunction)
+    {
+        $queries = $this->queryToBuild->getFilterQueries();
+        foreach($queries as $key =>  $query) {
+            $canBeRemoved = $filterFunction($key, $query);
+            if($canBeRemoved) {
+                unset($queries[$key]);
+            }
+        }
+
+        $this->queryToBuild->setFilterQueries($queries);
+        return $this;
+    }
+
+    /**
+     * Passes the alternative query to the Query
+     * @param string $query
+     * @return $this
+     */
+    public function useAlternativeQuery(string $query)
+    {
+        $this->queryToBuild->getEDisMax()->setQueryAlternative($query);
+        return $this;
+    }
+
+    /**
+     * Remove the alternative query from the Query.
+     *
+     * @return $this
+     */
+    public function removeAlternativeQuery()
+    {
+        $this->queryToBuild->getEDisMax()->setQueryAlternative(null);
+        return $this;
+    }
+
+    /**
+     * Applies a custom Faceting configuration to the query.
+     *
+     * @param Faceting $faceting
+     * @return $this
+     */
+    public function useFaceting(Faceting $faceting)
+    {
+        return $faceting->build($this);
+    }
+
+    /**
+     * @param FieldCollapsing $fieldCollapsing
+     * @return $this
+     */
+    public function useFieldCollapsing(FieldCollapsing $fieldCollapsing)
+    {
+        return $fieldCollapsing->build($this);
+    }
+
+    /**
+     * Applies a custom initialized grouping to the query.
+     *
+     * @param Grouping $grouping
+     * @return $this
+     */
+    public function useGrouping(Grouping $grouping)
+    {
+        return $grouping->build($this);
+    }
+
+    /**
+     * @param Highlighting $highlighting
+     * @return $this
+     */
+    public function useHighlighting(Highlighting $highlighting)
+    {
+        return $highlighting->build($this);
+    }
+
+    /**
+     * @param boolean $debugMode
+     * @return $this
+     */
+    public function useDebug($debugMode)
+    {
+        if (!$debugMode) {
+            $this->queryToBuild->addParam('debugQuery', null);
+            $this->queryToBuild->addParam('echoParams', null);
+            return $this;
+        }
+
+        $this->queryToBuild->addParam('debugQuery', 'true');
+        $this->queryToBuild->addParam('echoParams', 'all');
+
+        return $this;
+    }
+
+    /**
+     * @param Elevation $elevation
+     * @return QueryBuilder
+     */
+    public function useElevation(Elevation $elevation)
+    {
+        return $elevation->build($this);
+    }
+
+    /**
+     * @param Spellchecking $spellchecking
+     * @return $this
+     */
+    public function useSpellchecking(Spellchecking $spellchecking)
+    {
+        return $spellchecking->build($this);
+    }
+
+    /**
+     * Applies a custom configured PhraseFields to the query.
+     *
+     * @param PhraseFields $phraseFields
+     * @return $this
+     */
+    public function usePhraseFields(PhraseFields $phraseFields)
+    {
+        return $phraseFields->build($this);
+    }
+
+    /**
+     * Applies a custom configured BigramPhraseFields to the query.
+     *
+     * @param BigramPhraseFields $bigramPhraseFields
+     * @return $this
+     */
+    public function useBigramPhraseFields(BigramPhraseFields $bigramPhraseFields)
+    {
+        return $bigramPhraseFields->build($this);
+    }
+
+    /**
+     * Applies a custom configured TrigramPhraseFields to the query.
+     *
+     * @param TrigramPhraseFields $trigramPhraseFields
+     * @return $this
+     */
+    public function useTrigramPhraseFields(TrigramPhraseFields $trigramPhraseFields)
+    {
+        return $trigramPhraseFields->build($this);
+    }
+}

Classes/Domain/Search/Query/ExtractingQuery.php

@@ -0,0 +1,47 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use Solarium\QueryType\Extract\Query as SolariumExtractQuery;
+
+/**
+ * Specialized query for content extraction using Solr Cell
+ *
+ */
+class ExtractingQuery extends SolariumExtractQuery
+{
+    /**
+     * Constructor
+     *
+     * @param string $file Absolute path to the file to extract content and meta data from.
+     */
+    public function __construct($file)
+    {
+        parent::__construct();
+        $this->setFile($file);
+        $this->addParam('extractFormat', 'text');
+    }
+
+}

Classes/Domain/Search/Query/Helper/EscapeService.php

@@ -0,0 +1,147 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\Helper;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+/**
+ * The EscpaeService is responsible to escape the querystring as expected for Apache Solr.
+ *
+ * This class should have no dependencies since it only contains static functions
+ *
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class EscapeService {
+
+    /**
+     * Quote and escape search strings
+     *
+     * @param string|int|double $string String to escape
+     * @return string|int|double The escaped/quoted string
+     */
+    public static function escape($string)
+    {
+        // when we have a numeric string only, nothing needs to be done
+        if (is_numeric($string)) {
+            return $string;
+        }
+
+        // when no whitespaces are in the query we can also just escape the special characters
+        if (preg_match('/\W/', $string) != 1) {
+            return static::escapeSpecialCharacters($string);
+        }
+
+        // when there are no quotes inside the query string we can also just escape the whole string
+        $hasQuotes = strrpos($string, '"') !== false;
+        if (!$hasQuotes) {
+            return static::escapeSpecialCharacters($string);
+        }
+
+        $result = static::tokenizeByQuotesAndEscapeDependingOnContext($string);
+
+        return $result;
+    }
+
+    /**
+     * Applies trim and htmlspecialchars on the querystring to use it as output.
+     *
+     * @param mixed $string
+     * @return string
+     */
+    public static function clean($string): string
+    {
+        $string = trim($string);
+        $string = htmlspecialchars($string);
+        return $string;
+    }
+
+    /**
+     * This method is used to escape the content in the query string surrounded by quotes
+     * different then when it is not in a quoted context.
+     *
+     * @param string $string
+     * @return string
+     */
+    protected static function tokenizeByQuotesAndEscapeDependingOnContext($string)
+    {
+        $result = '';
+        $quotesCount = substr_count($string, '"');
+        $isEvenAmountOfQuotes = $quotesCount % 2 === 0;
+
+        // go over all quote segments and apply escapePhrase inside a quoted
+        // context and escapeSpecialCharacters outside the quoted context.
+        $segments = explode('"', $string);
+        $segmentsIndex = 0;
+        foreach ($segments as $segment) {
+            $isInQuote = $segmentsIndex % 2 !== 0;
+            $isLastQuote = $segmentsIndex === $quotesCount;
+
+            if ($isLastQuote && !$isEvenAmountOfQuotes) {
+                $result .= '\"';
+            }
+
+            if ($isInQuote && !$isLastQuote) {
+                $result .= static::escapePhrase($segment);
+            } else {
+                $result .= static::escapeSpecialCharacters($segment);
+            }
+
+            $segmentsIndex++;
+        }
+
+        return $result;
+    }
+
+    /**
+     * Escapes a value meant to be contained in a phrase with characters with
+     * special meanings in Lucene query syntax.
+     *
+     * @param string $value Unescaped - "dirty" - string
+     * @return string Escaped - "clean" - string
+     */
+    protected static function escapePhrase($value)
+    {
+        $pattern = '/("|\\\)/';
+        $replace = '\\\$1';
+
+        return '"' . preg_replace($pattern, $replace, $value) . '"';
+    }
+
+    /**
+     * Escapes characters with special meanings in Lucene query syntax.
+     *
+     * @param string $value Unescaped - "dirty" - string
+     * @return string Escaped - "clean" - string
+     */
+    protected static function escapeSpecialCharacters($value)
+    {
+        // list taken from http://lucene.apache.org/core/4_4_0/queryparser/org/apache/lucene/queryparser/classic/package-summary.html#package_description
+        // which mentions: + - && || ! ( ) { } [ ] ^ " ~ * ? : \ /
+        // of which we escape: ( ) { } [ ] ^ " ~ : \ /
+        // and explicitly don't escape: + - && || ! * ?
+        $pattern = '/(\\(|\\)|\\{|\\}|\\[|\\]|\\^|"|~|\:|\\\\|\\/)/';
+        $replace = '\\\$1';
+
+        return preg_replace($pattern, $replace, $value);
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/AbstractDeactivatable.php

@@ -0,0 +1,46 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+abstract class AbstractDeactivatable {
+
+    /**
+     * @var bool
+     */
+    protected $isEnabled = false;
+    /**
+     * @return boolean
+     */
+    public function getIsEnabled()
+    {
+        return $this->isEnabled;
+    }
+    /**
+     * @param boolean $isEnabled
+     */
+    public function setIsEnabled($isEnabled)
+    {
+        $this->isEnabled = $isEnabled;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/AbstractFieldList.php

@@ -0,0 +1,115 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The AbstractFieldList class
+ */
+abstract class AbstractFieldList extends AbstractDeactivatable
+{
+    /**
+     * @var array
+     */
+    protected $fieldList = [];
+
+    /**
+     * Parameter key which should be used for Apache Solr URL query
+     *
+     * @var string
+     */
+    protected $parameterKey = '';
+
+    /**
+     * FieldList parameter builder constructor.
+     *
+     * @param array $fieldList
+     */
+    public function __construct($isEnabled, array $fieldList = [])
+    {
+        $this->isEnabled = $isEnabled;
+        $this->fieldList = $fieldList;
+    }
+
+    /**
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return array
+     */
+    protected static function buildFieldList(string $fieldListString, string $delimiter):array
+    {
+        $fields = GeneralUtility::trimExplode($delimiter, $fieldListString, true);
+        $fieldList = [];
+
+        foreach ($fields as $field) {
+            $fieldNameAndBoost = explode('^', $field);
+
+            $boost = 1.0;
+            if (isset($fieldNameAndBoost[1])) {
+                $boost = floatval($fieldNameAndBoost[1]);
+            }
+
+            $fieldName = $fieldNameAndBoost[0];
+            $fieldList[$fieldName] = $boost;
+        }
+        return $fieldList;
+    }
+
+    /**
+     * @param string $fieldName
+     * @param float $boost
+     *
+     * @return AbstractFieldList
+     */
+    public function add(string $fieldName, float $boost = 1.0): AbstractFieldList
+    {
+        $this->fieldList[$fieldName] = (float)$boost;
+        return $this;
+    }
+
+    /**
+     * Creates the string representation
+     *
+     * @param string $delimiter
+     * @return string
+     */
+    public function toString(string $delimiter = ' ')
+    {
+        $fieldListString = '';
+
+        foreach ($this->fieldList as $fieldName => $fieldBoost) {
+            $fieldListString .= $fieldName;
+
+            if ($fieldBoost != 1.0) {
+                $fieldListString .= '^' . number_format($fieldBoost, 1, '.', '');
+            }
+
+            $fieldListString .= $delimiter;
+        }
+
+        return rtrim($fieldListString, $delimiter);
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/BigramPhraseFields.php

@@ -0,0 +1,95 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The BigramPhraseFields class
+ */
+class BigramPhraseFields extends AbstractFieldList implements ParameterBuilder
+{
+    /**
+     * Parameter key which should be used for Apache Solr URL query
+     *
+     * @var string
+     */
+    protected $parameterKey = 'pf2';
+
+    /**
+     * Parses the string representation of the fieldList (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return BigramPhraseFields
+     */
+    public static function fromString(string $fieldListString, string $delimiter = ',') : BigramPhraseFields
+    {
+        return self::initializeFromString($fieldListString, $delimiter);
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return BigramPhraseFields
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getBigramPhraseSearchIsEnabled();
+        if (!$isEnabled) {
+            return new BigramPhraseFields(false);
+        }
+
+        return self::fromString((string)$solrConfiguration->getSearchQueryBigramPhraseFields());
+    }
+
+    /**
+     * Parses the string representation of the fieldList (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return BigramPhraseFields
+     */
+    protected static function initializeFromString(string $fieldListString, string $delimiter = ',') : BigramPhraseFields
+    {
+        $fieldList = self::buildFieldList($fieldListString, $delimiter);
+        return new BigramPhraseFields(true, $fieldList);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $bigramPhraseFieldsString = $this->toString();
+        if ($bigramPhraseFieldsString === '' || !$this->getIsEnabled()) {
+            return $parentBuilder;
+        }
+
+        $parentBuilder->getQuery()->getEDisMax()->setPhraseBigramFields($bigramPhraseFieldsString);
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Elevation.php

@@ -0,0 +1,139 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2018 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The Elevation ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the elevation.
+ */
+class Elevation extends AbstractDeactivatable implements ParameterBuilder
+{
+    /**
+     * @var bool
+     */
+    protected $isForced = true;
+
+    /**
+     * @var bool
+     */
+    protected $markElevatedResults = true;
+
+    /**
+     * Elevation constructor.
+     * @param boolean $isEnabled
+     * @param boolean $isForced
+     * @param boolean $markElevatedResults
+     */
+    public function __construct($isEnabled = false, $isForced = true, $markElevatedResults = true)
+    {
+        $this->isEnabled = $isEnabled;
+        $this->isForced = $isForced;
+        $this->markElevatedResults = $markElevatedResults;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getIsForced(): bool
+    {
+        return $this->isForced;
+    }
+
+    /**
+     * @param boolean $isForced
+     */
+    public function setIsForced(bool $isForced)
+    {
+        $this->isForced = $isForced;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getMarkElevatedResults(): bool
+    {
+        return $this->markElevatedResults;
+    }
+
+    /**
+     * @param boolean $markElevatedResults
+     */
+    public function setMarkElevatedResults(bool $markElevatedResults)
+    {
+        $this->markElevatedResults = $markElevatedResults;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Elevation
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getSearchElevation();
+        if (!$isEnabled) {
+            return new Elevation(false);
+        }
+
+        $force = $solrConfiguration->getSearchElevationForceElevation();
+        $markResults = $solrConfiguration->getSearchElevationMarkElevatedResults();
+        return new Elevation(true, $force, $markResults);
+    }
+
+    /**
+     * @return Elevation
+     */
+    public static function getEmpty()
+    {
+        return new Elevation(false);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+        if (!$this->getIsEnabled()) {
+            $query->addParam('enableElevation', null);
+            $query->addParam('forceElevation', null);
+            $query->removeField('isElevated:[elevated]');
+            return $parentBuilder;
+        }
+
+        $query->addParam('enableElevation', 'true');
+        $forceElevationString = $this->getIsForced() ? 'true' : 'false';
+        $query->addParam('forceElevation', $forceElevationString);
+
+        if ($this->getMarkElevatedResults()) {
+            $query->addField('isElevated:[elevated]');
+        }
+
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Faceting.php

@@ -0,0 +1,282 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\Domain\Search\Query\QueryBuilder;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\SortingExpression;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The Faceting ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the highlighting.
+ */
+class Faceting extends AbstractDeactivatable implements ParameterBuilder
+{
+
+    /**
+     * @var string
+     */
+    protected $sorting = '';
+
+    /**
+     * @var int
+     */
+    protected $minCount = 1;
+
+    /**
+     * @var int
+     */
+    protected $limit = 10;
+
+    /**
+     * @var array
+     */
+    protected $fields = [];
+
+    /**
+     * @var array
+     */
+    protected $additionalParameters = [];
+
+    /**
+     * Faceting constructor.
+     *
+     * @param bool $isEnabled
+     * @param string $sorting
+     * @param int $minCount
+     * @param int $limit
+     * @param array $fields
+     * @param array $additionalParameters
+     */
+    public function __construct($isEnabled, $sorting = '', $minCount = 1, $limit = 10, $fields = [], $additionalParameters = [])
+    {
+        $this->isEnabled = $isEnabled;
+        $this->sorting = $sorting;
+        $this->minCount = $minCount;
+        $this->limit = $limit;
+        $this->fields = $fields;
+        $this->additionalParameters = $additionalParameters;
+    }
+
+    /**
+     * @return string
+     */
+    public function getSorting()
+    {
+        return $this->sorting;
+    }
+
+    /**
+     * @param string $sorting
+     */
+    public function setSorting($sorting)
+    {
+        $this->sorting = $sorting;
+    }
+
+    /**
+     * @return int
+     */
+    public function getMinCount()
+    {
+        return $this->minCount;
+    }
+
+    /**
+     * @param int $minCount
+     */
+    public function setMinCount($minCount)
+    {
+        $this->minCount = $minCount;
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getLimit()
+    {
+        return $this->limit;
+    }
+
+    /**
+     * @param mixed $limit
+     */
+    public function setLimit($limit)
+    {
+        $this->limit = $limit;
+    }
+
+    /**
+     * @return array
+     */
+    public function getFields()
+    {
+        return $this->fields;
+    }
+
+    /**
+     * @param array $fields
+     */
+    public function setFields(array $fields)
+    {
+        $this->fields = $fields;
+    }
+
+    /**
+     * @param string $fieldName
+     */
+    public function addField($fieldName)
+    {
+        $this->fields[] = $fieldName;
+    }
+
+    /**
+     * @return array
+     */
+    public function getAdditionalParameters(): array
+    {
+        return $this->additionalParameters;
+    }
+
+    /**
+     * @param array $additionalParameters
+     */
+    public function setAdditionalParameters(array $additionalParameters)
+    {
+        $this->additionalParameters = $additionalParameters;
+    }
+
+    /**
+     * @param array $value
+     */
+    public function addAdditionalParameter($key, $value)
+    {
+        $this->additionalParameters[$key] = $value;
+    }
+
+    /**
+     * Reads the facet sorting configuration and applies it to the queryParameters.
+     *
+     * @param array $facetParameters
+     * @return array
+     */
+    protected function applySorting(array $facetParameters)
+    {
+        $sortingExpression = new SortingExpression();
+        $globalSortingExpression = $sortingExpression->getForFacet($this->sorting);
+
+        if (!empty($globalSortingExpression)) {
+            $facetParameters['facet.sort'] = $globalSortingExpression;
+        }
+
+        return $facetParameters;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Faceting
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getSearchFaceting();
+        if (!$isEnabled) {
+            return new Faceting(false);
+        }
+
+        $minCount = $solrConfiguration->getSearchFacetingMinimumCount();
+        $limit = $solrConfiguration->getSearchFacetingFacetLimit();
+        $sorting = $solrConfiguration->getSearchFacetingSortBy();
+
+        return new Faceting($isEnabled, $sorting, $minCount, $limit);
+    }
+
+    /**
+     * @return Faceting
+     */
+    public static function getEmpty()
+    {
+        return new Faceting(false);
+    }
+
+    /**
+     * Retrieves all parameters that are required for faceting.
+     *
+     * @return array
+     */
+    protected function getFacetParameters() {
+        $facetParameters = [];
+        $facetParameters['facet'] = 'true';
+        $facetParameters['facet.mincount'] = $this->getMinCount();
+        $facetParameters['facet.limit'] = $this->getLimit();
+        $facetParameters['facet.field'] = $this->getFields();
+
+        foreach ($this->getAdditionalParameters() as $additionalParameterKey => $additionalParameterValue) {
+            $facetParameters[$additionalParameterKey] = $additionalParameterValue;
+        }
+
+        if ($facetParameters['json.facet']) {
+            $facetParameters['json.facet'] = json_encode($facetParameters['json.facet']);
+        }
+
+        $facetParameters = $this->applySorting($facetParameters);
+        return $facetParameters;
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return QueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+        if (!$this->getIsEnabled()) {
+            //@todo use unset functionality when present
+            $query->addParam('facet', null);
+            $query->addParam('lex', null);
+            $query->addParam('json.mincount', null);
+            $query->addParam('json.limit', null);
+            $query->addParam('json.field', null);
+            $query->addParam('facet.sort', null);
+
+            $params = $query->getParams();
+            foreach($params as $key => $value) {
+                if (strpos($key, 'f.') !== false) {
+                    $query->addParam($key, null);
+                }
+            }
+
+            return $parentBuilder;
+        }
+
+        //@todo check of $this->queryToBuilder->getFacetSet() can be used
+        $facetingParameters = $this->getFacetParameters();
+        foreach($facetingParameters as $key => $value) {
+            $query->addParam($key, $value);
+        }
+
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/FieldCollapsing.php

@@ -0,0 +1,159 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The FieldCollapsing ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the field collapsing.
+ */
+class FieldCollapsing extends AbstractDeactivatable implements ParameterBuilder
+{
+    /**
+     * @var string
+     */
+    protected $collapseFieldName = 'variantId';
+
+    /**
+     * @var bool
+     */
+    protected $expand = false;
+
+    /**
+     * @var int
+     */
+    protected $expandRowCount = 10;
+
+    /**
+     * FieldCollapsing constructor.
+     * @param bool $isEnabled
+     * @param string $collapseFieldName
+     * @param bool $expand
+     * @param int $expandRowCount
+     */
+    public function __construct($isEnabled, $collapseFieldName = 'variantId', $expand = false, $expandRowCount = 10)
+    {
+        $this->isEnabled = $isEnabled;
+        $this->collapseFieldName = $collapseFieldName;
+        $this->expand = $expand;
+        $this->expandRowCount = $expandRowCount;
+    }
+
+    /**
+     * @return string
+     */
+    public function getCollapseFieldName(): string
+    {
+        return $this->collapseFieldName;
+    }
+
+    /**
+     * @param string $collapseFieldName
+     */
+    public function setCollapseFieldName(string $collapseFieldName)
+    {
+        $this->collapseFieldName = $collapseFieldName;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getIsExpand(): bool
+    {
+        return $this->expand;
+    }
+
+    /**
+     * @param boolean $expand
+     */
+    public function setExpand(bool $expand)
+    {
+        $this->expand = $expand;
+    }
+
+    /**
+     * @return int
+     */
+    public function getExpandRowCount(): int
+    {
+        return $this->expandRowCount;
+    }
+
+    /**
+     * @param int $expandRowCount
+     */
+    public function setExpandRowCount(int $expandRowCount)
+    {
+        $this->expandRowCount = $expandRowCount;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return FieldCollapsing
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getSearchVariants();
+        if (!$isEnabled) {
+            return new FieldCollapsing(false);
+        }
+
+        $collapseField = $solrConfiguration->getSearchVariantsField();
+        $expand = (bool)$solrConfiguration->getSearchVariantsExpand();
+        $expandRows = $solrConfiguration->getSearchVariantsLimit();
+
+        return new FieldCollapsing(true, $collapseField, $expand, $expandRows);
+    }
+
+    /**
+     * @return FieldCollapsing
+     */
+    public static function getEmpty()
+    {
+        return new FieldCollapsing(false);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+        if(!$this->getIsEnabled()) {
+            return $parentBuilder;
+        }
+
+        $parentBuilder->useFilter('{!collapse field=' . $this->getCollapseFieldName(). '}', 'fieldCollapsing');
+        if($this->getIsExpand()) {
+            $query->addParam('expand', 'true');
+            $query->addParam('expand.rows', $this->getExpandRowCount());
+        }
+
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Filters.php

@@ -0,0 +1,158 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The Filters ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the filtering.
+ */
+class Filters
+{
+
+    /**
+     * @var array
+     */
+    protected $filters = [];
+
+    /**
+     * Removes a filter on a field
+     *
+     * @param string $filterFieldName The field name the filter should be removed for
+     * @return void
+     */
+    public function removeByFieldName($filterFieldName)
+    {
+        $this->removeByPrefix($filterFieldName . ':');
+    }
+
+    /**
+     * @param string $filterFieldName
+     */
+    public function removeByPrefix($filterFieldName)
+    {
+        foreach ($this->filters as $key => $filterString) {
+            if (GeneralUtility::isFirstPartOfStr($filterString, $filterFieldName)) {
+                unset($this->filters[$key]);
+            }
+        }
+    }
+
+    /**
+     * Removes a filter based on name of filter array
+     *
+     * @param string $name name of the filter
+     */
+    public function removeByName($name)
+    {
+        unset($this->filters[$name]);
+    }
+
+
+    /**
+     * @param string $filterString
+     * @param string $name
+     */
+    public function add($filterString, $name = '')
+    {
+        if ($name !== '') {
+            $this->filters[$name] = $filterString;
+        } else {
+            $this->filters[] = $filterString;
+        }
+    }
+
+    /**
+     * Add's multiple filters to the filter collection.
+     *
+     * @param array $filterArray
+     * @return Filters
+     */
+    public function addMultiple($filterArray)
+    {
+        foreach($filterArray as $key => $value) {
+            if (!$this->hasWithName($key)) {
+                $this->add($value, $key);
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param string $name
+     * @return bool
+     */
+    public function hasWithName($name)
+    {
+        return array_key_exists($name, $this->filters);
+    }
+
+    /**
+     * Removes a filter by the filter value. The value has the following format:
+     *
+     * "fieldname:value"
+     *
+     * @param string $filterString The filter to remove, in the form of field:value
+     */
+    public function removeByValue($filterString)
+    {
+        $key = array_search($filterString, $this->filters);
+        if ($key === false) {
+            // value not found, nothing to do
+            return;
+        }
+        unset($this->filters[$key]);
+    }
+
+    /**
+     * Gets all currently applied filters.
+     *
+     * @return array Array of filters
+     */
+    public function getValues()
+    {
+        return $this->filters;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Filters
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        return new Filters();
+    }
+
+    /**
+     * @return Filters
+     */
+    public static function getEmpty()
+    {
+        return new Filters();
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Grouping.php

@@ -0,0 +1,254 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The Grouping ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the grouping.
+ */
+class Grouping extends AbstractDeactivatable implements ParameterBuilder
+{
+
+    /**
+     * @var array
+     */
+    protected $fields = [];
+
+    /**
+     * @var array
+     */
+    protected $sortings = [];
+
+    /**
+     * @var array
+     */
+    protected $queries = [];
+
+    /**
+     * @var int
+     */
+    protected $numberOfGroups = 5;
+
+    /**
+     * @var int
+     */
+    protected $resultsPerGroup = 1;
+
+    /**
+     * Grouping constructor.
+     *
+     * @param bool $isEnabled
+     * @param array $fields
+     * @param array $sortings
+     * @param array $queries
+     * @param int $numberOfGroups
+     * @param int $resultsPerGroup
+     */
+    public function __construct($isEnabled, array $fields = [], array $sortings = [], array $queries = [], $numberOfGroups = 5, $resultsPerGroup = 1)
+    {
+        $this->isEnabled = $isEnabled;
+        $this->fields = $fields;
+        $this->sortings = $sortings;
+        $this->queries = $queries;
+        $this->numberOfGroups = $numberOfGroups;
+        $this->resultsPerGroup = $resultsPerGroup;
+    }
+
+    /**
+     * @return array
+     */
+    public function getFields()
+    {
+        return $this->fields;
+    }
+
+    /**
+     * @param array $fields
+     */
+    public function setFields(array $fields)
+    {
+        $this->fields = $fields;
+    }
+
+    /**
+     * @param string $field
+     */
+    public function addField(string $field)
+    {
+        $this->fields[] = $field;
+    }
+
+    /**
+     * @return array
+     */
+    public function getSortings()
+    {
+        return $this->sortings;
+    }
+
+    /**
+     * @param string $sorting
+     */
+    public function addSorting($sorting)
+    {
+        $this->sortings[] = $sorting;
+    }
+
+    /**
+     * @param array $sortings
+     */
+    public function setSortings(array $sortings)
+    {
+        $this->sortings = $sortings;
+    }
+
+    /**
+     * @return array
+     */
+    public function getQueries(): array
+    {
+        return $this->queries;
+    }
+
+    /**
+     * @param string $query
+     */
+    public function addQuery($query)
+    {
+        $this->queries[] = $query;
+    }
+
+    /**
+     * @param array $queries
+     */
+    public function setQueries(array $queries)
+    {
+        $this->queries = $queries;
+    }
+
+    /**
+     * @return int
+     */
+    public function getNumberOfGroups()
+    {
+        return $this->numberOfGroups;
+    }
+
+    /**
+     * @param int $numberOfGroups
+     */
+    public function setNumberOfGroups($numberOfGroups)
+    {
+        $this->numberOfGroups = $numberOfGroups;
+    }
+
+    /**
+     * @return int
+     */
+    public function getResultsPerGroup()
+    {
+        return $this->resultsPerGroup;
+    }
+
+    /**
+     * @param int $resultsPerGroup
+     */
+    public function setResultsPerGroup($resultsPerGroup)
+    {
+        $resultsPerGroup = max(intval($resultsPerGroup), 0);
+        $this->resultsPerGroup = $resultsPerGroup;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Grouping
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getSearchGrouping();
+        if (!$isEnabled) {
+            return new Grouping(false);
+        }
+
+        $fields = [];
+        $queries = [];
+        $sortings = [];
+
+        $resultsPerGroup = $solrConfiguration->getSearchGroupingHighestGroupResultsLimit();
+        $configuredGroups = $solrConfiguration->getSearchGroupingGroupsConfiguration();
+        $numberOfGroups = $solrConfiguration->getSearchGroupingNumberOfGroups();
+        $sortBy = $solrConfiguration->getSearchGroupingSortBy();
+
+        foreach ($configuredGroups as $groupName => $groupConfiguration) {
+            if (isset($groupConfiguration['field'])) {
+                $fields[] = $groupConfiguration['field'];
+            } elseif (isset($groupConfiguration['query'])) {
+                $queries[] = $groupConfiguration['query'];
+            }
+        }
+
+        if (!empty(trim($sortBy))) {
+            $sortings[] = $sortBy;
+        }
+
+        return new Grouping($isEnabled, $fields, $sortings, $queries, $numberOfGroups, $resultsPerGroup);
+    }
+
+    /**
+     * @return Grouping
+     */
+    public static function getEmpty()
+    {
+        return new Grouping(false);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+        if(!$this->getIsEnabled()) {
+            $query->removeComponent($query->getGrouping());
+            return $parentBuilder;
+        }
+
+        $query->getGrouping()->setFields($this->getFields());
+        $query->getGrouping()->setLimit($this->getResultsPerGroup());
+        $query->getGrouping()->setQueries($this->getQueries());
+        $query->getGrouping()->setFormat('grouped');
+        $query->getGrouping()->setNumberOfGroups(true);
+
+        $query->setRows($this->getNumberOfGroups());
+
+        $sorting = implode(' ', $this->getSortings());
+        $query->getGrouping()->setSort($sorting);
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Highlighting.php

@@ -0,0 +1,211 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\Domain\Search\Query\QueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The Highlighting ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the highlighting.
+ */
+class Highlighting extends AbstractDeactivatable implements ParameterBuilder
+{
+    /**
+     * @var int
+     */
+    protected $fragmentSize = 200;
+
+    /**
+     * @var string
+     */
+    protected $highlightingFieldList = '';
+
+    /**
+     * @var string
+     */
+    protected $prefix = '';
+
+    /**
+     * @var string
+     */
+    protected $postfix = '';
+
+    /**
+     * Highlighting constructor.
+     *
+     * @param bool $isEnabled
+     * @param int $fragmentSize
+     * @param string $highlightingFieldList
+     * @param string $prefix
+     * @param string $postfix
+     */
+    public function __construct($isEnabled = false, $fragmentSize = 200, $highlightingFieldList = '', $prefix = '', $postfix = '')
+    {
+        $this->isEnabled = $isEnabled;
+        $this->fragmentSize = $fragmentSize;
+        $this->highlightingFieldList = $highlightingFieldList;
+        $this->prefix = $prefix;
+        $this->postfix = $postfix;
+    }
+
+    /**
+     * @return int
+     */
+    public function getFragmentSize(): int
+    {
+        return $this->fragmentSize;
+    }
+
+    /**
+     * @param int $fragmentSize
+     */
+    public function setFragmentSize(int $fragmentSize)
+    {
+        $this->fragmentSize = $fragmentSize;
+    }
+
+    /**
+     * @return string
+     */
+    public function getHighlightingFieldList(): string
+    {
+        return $this->highlightingFieldList;
+    }
+
+    /**
+     * @param string $highlightingFieldList
+     */
+    public function setHighlightingFieldList(string $highlightingFieldList)
+    {
+        $this->highlightingFieldList = $highlightingFieldList;
+    }
+
+    /**
+     * @return string
+     */
+    public function getPrefix(): string
+    {
+        return $this->prefix;
+    }
+
+    /**
+     * @param string $prefix
+     */
+    public function setPrefix(string $prefix)
+    {
+        $this->prefix = $prefix;
+    }
+
+    /**
+     * @return string
+     */
+    public function getPostfix(): string
+    {
+        return $this->postfix;
+    }
+
+    /**
+     * @param string $postfix
+     */
+    public function setPostfix(string $postfix)
+    {
+        $this->postfix = $postfix;
+    }
+
+    /**
+     * @return bool
+     */
+    public function getUseFastVectorHighlighter()
+    {
+        return ($this->fragmentSize >= 18);
+    }
+
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Highlighting
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getSearchResultsHighlighting();
+        if (!$isEnabled) {
+            return new Highlighting(false);
+        }
+
+        $fragmentSize = $solrConfiguration->getSearchResultsHighlightingFragmentSize();
+        $highlightingFields = $solrConfiguration->getSearchResultsHighlightingFields();
+        $wrap = explode('|', $solrConfiguration->getSearchResultsHighlightingWrap());
+        $prefix = isset($wrap[0]) ? $wrap[0] : '';
+        $postfix = isset($wrap[1]) ? $wrap[1] : '';
+
+
+        return new Highlighting($isEnabled, $fragmentSize, $highlightingFields, $prefix, $postfix);
+    }
+
+    /**
+     * @return Highlighting
+     */
+    public static function getEmpty()
+    {
+        return new Highlighting(false);
+    }
+
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+        if(!$this->getIsEnabled()) {
+            $query->removeComponent($query->getHighlighting());
+            return $parentBuilder;
+        }
+
+        $query->getHighlighting()->setFragSize($this->getFragmentSize());
+        $query->getHighlighting()->setFields(GeneralUtility::trimExplode(",", $this->getHighlightingFieldList()));
+
+        if ($this->getUseFastVectorHighlighter()) {
+            $query->getHighlighting()->setUseFastVectorHighlighter(true);
+            $query->getHighlighting()->setTagPrefix($this->getPrefix());
+            $query->getHighlighting()->setTagPostfix($this->getPostfix());
+        } else {
+            $query->getHighlighting()->setUseFastVectorHighlighter(false);
+            $query->getHighlighting()->setTagPrefix('');
+            $query->getHighlighting()->setTagPostfix('');
+        }
+
+        if ($this->getPrefix() !== '' && $this->getPostfix() !== '') {
+            $query->getHighlighting()->setSimplePrefix($this->getPrefix());
+            $query->getHighlighting()->setSimplePostfix($this->getPostfix());
+        }
+
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Operator.php

@@ -0,0 +1,106 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+
+/**
+ * The Operator ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the operator q.op.
+ */
+class Operator extends AbstractDeactivatable
+{
+    const OPERATOR_AND = 'AND';
+    const OPERATOR_OR = 'OR';
+
+    /**
+     * @var string
+     */
+    protected $operator = 'AND';
+
+    /**
+     * Faceting constructor.
+     *
+     * @param bool $isEnabled
+     * @param string $operator
+     */
+    public function __construct($isEnabled, $operator = Operator::OPERATOR_AND)
+    {
+        $this->isEnabled = $isEnabled;
+        $this->setOperator($operator);
+    }
+
+    /**
+     * @param string $operator
+     */
+    public function setOperator($operator)
+    {
+        if (!in_array($operator, [self::OPERATOR_AND, self::OPERATOR_OR])) {
+            throw new \InvalidArgumentException("Invalid operator");
+        }
+
+        $this->operator = $operator;
+    }
+
+    /**
+     * @return string
+     */
+    public function getOperator(): string
+    {
+        return $this->operator;
+    }
+
+    /**
+     * @return Operator
+     */
+    public static function getEmpty(): Operator
+    {
+        return new Operator(false);
+    }
+
+    /**
+     * @return Operator
+     */
+    public static function getAnd(): Operator
+    {
+        return new Operator(true, static::OPERATOR_AND);
+    }
+
+    /**
+     * @return Operator
+     */
+    public static function getOr(): Operator
+    {
+        return new Operator(true, static::OPERATOR_OR);
+    }
+
+    /**
+     * @param string $operator
+     * @return Operator
+     */
+    public static function fromString($operator)
+    {
+        return new Operator(true, $operator);
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/ParameterBuilder.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+
+/**
+ * The implementation of ParameterBuilder is responsible to build an array with
+ * the query parameter that are needed for solr
+ *
+ * Interface ParameterProvider
+ */
+interface ParameterBuilder {
+
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder;
+}

Classes/Domain/Search/Query/ParameterBuilder/PhraseFields.php

@@ -0,0 +1,95 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The PhraseFields class
+ */
+class PhraseFields extends AbstractFieldList implements ParameterBuilder
+{
+    /**
+     * Parameter key which should be used for Apache Solr URL query
+     *
+     * @var string
+     */
+    protected $parameterKey = 'pf';
+
+    /**
+     * Parses the string representation of the fieldList (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return PhraseFields
+     */
+    public static function fromString(string $fieldListString, string $delimiter = ',') : PhraseFields
+    {
+        return self::initializeFromString($fieldListString, $delimiter);
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return PhraseFields
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getPhraseSearchIsEnabled();
+        if (!$isEnabled) {
+            return new PhraseFields(false);
+        }
+
+        return self::fromString((string)$solrConfiguration->getSearchQueryPhraseFields());
+    }
+
+    /**
+     * Parses the string representation of the fieldList (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return PhraseFields
+     */
+    protected static function initializeFromString(string $fieldListString, string $delimiter = ',') : PhraseFields
+    {
+        $fieldList = self::buildFieldList($fieldListString, $delimiter);
+        return new PhraseFields(true, $fieldList);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $phraseFieldString = $this->toString();
+        if ($phraseFieldString === '' || !$this->getIsEnabled()) {
+            return $parentBuilder;
+        }
+
+        $parentBuilder->getQuery()->getEDisMax()->setPhraseFields($phraseFieldString);
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/QueryFields.php

@@ -0,0 +1,117 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The QueryFields class holds all information for the query which fields should be used to query (Solr qf parameter).
+ */
+class QueryFields implements ParameterBuilder
+{
+
+    /**
+     * @var array
+     */
+    protected $queryFields = [];
+
+    /**
+     * QueryFields constructor.
+     *
+     * @param array $queryFields
+     */
+    public function __construct(array $queryFields = [])
+    {
+        $this->queryFields = $queryFields;
+    }
+
+    /**
+     * @param string $fieldName
+     * @param float $boost
+     */
+    public function set($fieldName, $boost = 1.0)
+    {
+        $this->queryFields[$fieldName] = (float)$boost;
+    }
+
+    /**
+     * Creates the string representation
+     *
+     * @param string $delimiter
+     * @return string
+     */
+    public function toString($delimiter = ' ') {
+        $queryFieldString = '';
+
+        foreach ($this->queryFields as $fieldName => $fieldBoost) {
+            $queryFieldString .= $fieldName;
+
+            if ($fieldBoost != 1.0) {
+                $queryFieldString .= '^' . number_format($fieldBoost, 1, '.', '');
+            }
+
+            $queryFieldString .= $delimiter;
+        }
+
+        return rtrim($queryFieldString, $delimiter);
+    }
+
+    /**
+     * Parses the string representation of the queryFields (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $queryFieldsString
+     * @param string $delimiter
+     * @return QueryFields
+     */
+    public static function fromString($queryFieldsString, $delimiter = ',') {
+        $fields = GeneralUtility::trimExplode($delimiter, $queryFieldsString, true);
+        $queryFields = [];
+
+        foreach ($fields as $field) {
+            $fieldNameAndBoost = explode('^', $field);
+
+            $boost = 1.0;
+            if (isset($fieldNameAndBoost[1])) {
+                $boost = floatval($fieldNameAndBoost[1]);
+            }
+
+            $fieldName = $fieldNameAndBoost[0];
+            $queryFields[$fieldName] = $boost;
+        }
+
+        return new QueryFields($queryFields);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $parentBuilder->getQuery()->getEDisMax()->setQueryFields($this->toString());
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/ReturnFields.php

@@ -0,0 +1,128 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The ReturnFields class is responsible to hold a list of field names that should be returned from
+ * solr.
+ */
+class ReturnFields implements ParameterBuilder
+{
+
+    /**
+     * @var array
+     */
+    protected $fieldList = [];
+
+    /**
+     * FieldList constructor.
+     *
+     * @param array $fieldList
+     */
+    public function __construct(array $fieldList = [])
+    {
+        $this->fieldList = $fieldList;
+    }
+
+    /**
+     * Adds a field to the list of fields to return. Also checks whether * is
+     * set for the fields, if so it's removed from the field list.
+     *
+     * @param string $fieldName Name of a field to return in the result documents
+     */
+    public function add($fieldName)
+    {
+        if (strpos($fieldName, '[') === false && strpos($fieldName, ']') === false && in_array('*', $this->fieldList)) {
+            $this->fieldList = array_diff($this->fieldList, ['*']);
+        }
+
+        $this->fieldList[] = $fieldName;
+    }
+
+    /**
+     * Removes a field from the list of fields to return (fl parameter).
+     *
+     * @param string $fieldName Field to remove from the list of fields to return
+     */
+    public function remove($fieldName)
+    {
+        $key = array_search($fieldName, $this->fieldList);
+
+        if ($key !== false) {
+            unset($this->fieldList[$key]);
+        }
+    }
+
+    /**
+     * @param string $delimiter
+     * @return string
+     */
+    public function toString($delimiter = ',')
+    {
+        return implode($delimiter, $this->fieldList);
+    }
+
+    /**
+     * @param string $fieldList
+     * @param string $delimiter
+     * @return ReturnFields
+     */
+    public static function fromString($fieldList, $delimiter = ',')
+    {
+        $fieldListArray = GeneralUtility::trimExplode($delimiter, $fieldList);
+        return static::fromArray($fieldListArray);
+    }
+
+    /**
+     * @param array $fieldListArray
+     * @return ReturnFields
+     */
+    public static function fromArray(array $fieldListArray)
+    {
+        return new ReturnFields($fieldListArray);
+    }
+
+    /**
+     * @return array
+     */
+    public function getValues()
+    {
+        return array_unique(array_values($this->fieldList));
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $parentBuilder->getQuery()->setFields($this->getValues());
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Slops.php

@@ -0,0 +1,257 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The Slops ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the several slop arguments.
+ */
+class Slops implements ParameterBuilder
+{
+    const NO_SLOP = null;
+
+    /**
+     * The qs parameter
+     *
+     * @var int
+     */
+    protected $querySlop = self::NO_SLOP;
+
+    /**
+     * @var int
+     */
+    protected $phraseSlop = self::NO_SLOP;
+
+    /**
+     * @var int
+     */
+    protected $bigramPhraseSlop = self::NO_SLOP;
+
+    /**
+     * @var int
+     */
+    protected $trigramPhraseSlop = self::NO_SLOP;
+
+    /**
+     * Slops constructor.
+     * @param int|null $querySlop
+     * @param int|null $phraseSlop
+     * @param int|null $bigramPhraseSlop
+     * @param int|null $trigramPhraseSlop
+     */
+    public function __construct($querySlop = self::NO_SLOP, $phraseSlop = self::NO_SLOP, $bigramPhraseSlop = self::NO_SLOP, $trigramPhraseSlop = self::NO_SLOP)
+    {
+        $this->querySlop = $querySlop;
+        $this->phraseSlop = $phraseSlop;
+        $this->bigramPhraseSlop = $bigramPhraseSlop;
+        $this->trigramPhraseSlop = $trigramPhraseSlop;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getHasQuerySlop()
+    {
+        return $this->querySlop !== null;
+    }
+
+    /**
+     * @return int|null
+     */
+    public function getQuerySlop()
+    {
+        return $this->querySlop;
+    }
+
+    /**
+     * @param int $querySlop
+     */
+    public function setQuerySlop(int $querySlop)
+    {
+        $this->querySlop = $querySlop;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getHasPhraseSlop()
+    {
+        return $this->phraseSlop !== null;
+    }
+
+
+    /**
+     * @return int|null
+     */
+    public function getPhraseSlop()
+    {
+        return $this->phraseSlop;
+    }
+
+    /**
+     * @param int $phraseSlop
+     */
+    public function setPhraseSlop(int $phraseSlop)
+    {
+        $this->phraseSlop = $phraseSlop;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getHasBigramPhraseSlop()
+    {
+        return $this->bigramPhraseSlop !== null;
+    }
+
+    /**
+     * @return int|null
+     */
+    public function getBigramPhraseSlop()
+    {
+        return $this->bigramPhraseSlop;
+    }
+
+    /**
+     * @param int $bigramPhraseSlop
+     */
+    public function setBigramPhraseSlop(int $bigramPhraseSlop)
+    {
+        $this->bigramPhraseSlop = $bigramPhraseSlop;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getHasTrigramPhraseSlop()
+    {
+        return $this->trigramPhraseSlop !== null;
+    }
+
+    /**
+     * @return int|null
+     */
+    public function getTrigramPhraseSlop()
+    {
+        return $this->trigramPhraseSlop;
+    }
+
+    /**
+     * @param int $trigramPhraseSlop
+     */
+    public function setTrigramPhraseSlop(int $trigramPhraseSlop)
+    {
+        $this->trigramPhraseSlop = $trigramPhraseSlop;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Slops
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $searchConfiguration = $solrConfiguration->getSearchConfiguration();
+        $querySlop = static::getQuerySlopFromConfiguration($searchConfiguration);
+        $phraseSlop = static::getPhraseSlopFromConfiguration($searchConfiguration);
+        $bigramPhraseSlop = static::getBigramPhraseSlopFromConfiguration($searchConfiguration);
+        $trigramPhraseSlop = static::getTrigramPhraseSlopFromConfiguration($searchConfiguration);
+        return new Slops($querySlop, $phraseSlop, $bigramPhraseSlop, $trigramPhraseSlop);
+    }
+
+    /**
+     * @param array $searchConfiguration
+     * @return int|null
+     */
+    protected static function getPhraseSlopFromConfiguration($searchConfiguration)
+    {
+        $phraseEnabled = !(empty($searchConfiguration['query.']['phrase']) || $searchConfiguration['query.']['phrase'] !== 1);
+        $phraseSlopConfigured = !empty($searchConfiguration['query.']['phrase.']['slop']);
+        return  ($phraseEnabled && $phraseSlopConfigured) ? $searchConfiguration['query.']['phrase.']['slop'] : self::NO_SLOP;
+    }
+
+    /**
+     * @param array $searchConfiguration
+     * @return int|null
+     */
+    protected static function getQuerySlopFromConfiguration($searchConfiguration)
+    {
+        $phraseEnabled = !(empty($searchConfiguration['query.']['phrase']) || $searchConfiguration['query.']['phrase'] !== 1);
+        $querySlopConfigured = !empty($searchConfiguration['query.']['phrase.']['querySlop']);
+        return ($phraseEnabled && $querySlopConfigured) ? $searchConfiguration['query.']['phrase.']['querySlop'] : self::NO_SLOP;
+    }
+
+    /**
+     * @param array $searchConfiguration
+     * @return int|null
+     */
+    protected static function getBigramPhraseSlopFromConfiguration($searchConfiguration)
+    {
+        $bigramPhraseEnabled = !empty($searchConfiguration['query.']['bigramPhrase']) && $searchConfiguration['query.']['bigramPhrase'] === 1;
+        $bigramSlopConfigured = !empty($searchConfiguration['query.']['bigramPhrase.']['slop']);
+        return ($bigramPhraseEnabled && $bigramSlopConfigured) ? $searchConfiguration['query.']['bigramPhrase.']['slop'] : self::NO_SLOP;
+    }
+
+    /**
+     * @param array $searchConfiguration
+     * @return int|null
+     */
+    protected static function getTrigramPhraseSlopFromConfiguration($searchConfiguration)
+    {
+        $trigramPhraseEnabled = !empty($searchConfiguration['query.']['trigramPhrase']) && $searchConfiguration['query.']['trigramPhrase'] === 1;
+        $trigramSlopConfigured = !empty($searchConfiguration['query.']['trigramPhrase.']['slop']);
+        return ($trigramPhraseEnabled && $trigramSlopConfigured) ? $searchConfiguration['query.']['trigramPhrase.']['slop'] : self::NO_SLOP;
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+
+        if ($this->getHasPhraseSlop()) {
+            $query->getEDisMax()->setPhraseSlop($this->getPhraseSlop());
+        }
+
+        if ($this->getHasBigramPhraseSlop()) {
+            $query->getEDisMax()->setPhraseBigramSlop($this->getBigramPhraseSlop());
+        }
+
+        if ($this->getHasTrigramPhraseSlop()) {
+            $query->getEDisMax()->setPhraseTrigramSlop($this->getTrigramPhraseSlop());
+        }
+
+        if ($this->getHasQuerySlop()) {
+            $query->getEDisMax()->setQueryPhraseSlop($this->getQuerySlop());
+        }
+
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Sorting.php

@@ -0,0 +1,112 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The Sorting ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the sorting.
+ */
+class Sorting extends AbstractDeactivatable
+{
+    const SORT_ASC = 'ASC';
+    const SORT_DESC = 'DESC';
+
+    /**
+     * @var string
+     */
+    protected $fieldName = '';
+
+    /**
+     * @var string
+     */
+    protected $direction = self::SORT_ASC;
+
+    /**
+     * Debug constructor.
+     *
+     * @param bool $isEnabled
+     * @param string $fieldName
+     * @param string $direction
+     */
+    public function __construct($isEnabled = false, $fieldName = '', $direction = self::SORT_ASC)
+    {
+        $this->isEnabled = $isEnabled;
+        $this->setFieldName($fieldName);
+        $this->setDirection($direction);
+    }
+
+    /**
+     * @return Sorting
+     */
+    public static function getEmpty()
+    {
+        return new Sorting(false);
+    }
+
+    /**
+     * @return string
+     */
+    public function getFieldName(): string
+    {
+        return $this->fieldName;
+    }
+
+    /**
+     * @param string $fieldName
+     */
+    public function setFieldName(string $fieldName)
+    {
+        $this->fieldName = $fieldName;
+    }
+
+    /**
+     * @return string
+     */
+    public function getDirection(): string
+    {
+        return $this->direction;
+    }
+
+    /**
+     * @param string $direction
+     */
+    public function setDirection(string $direction)
+    {
+        $this->direction = $direction;
+    }
+
+    /**
+     * Parses a sorting representation "<fieldName> <direction>"
+     * @param string $sortingString
+     * @return Sorting
+     */
+    public static function fromString($sortingString)
+    {
+        $parts = GeneralUtility::trimExplode(' ', $sortingString);
+        return new Sorting(true, $parts[0], $parts[1]);
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Sortings.php

@@ -0,0 +1,99 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * The Sorting ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the sorting.
+ */
+class Sortings extends AbstractDeactivatable
+{
+    /**
+     * @var array
+     */
+    protected $sortings = [];
+
+    /**
+     * Sortings constructor.
+     * @param bool $isEnabled
+     * @param array $sortings
+     */
+    public function __construct($isEnabled = false, $sortings = [])
+    {
+        $this->isEnabled = $isEnabled;
+        $this->setSortings($sortings);
+    }
+
+    /**
+     * @return Sortings
+     */
+    public static function getEmpty()
+    {
+        return new Sortings(false);
+    }
+
+    /**
+     * @return Sorting[]
+     */
+    public function getSortings(): array
+    {
+        return $this->sortings;
+    }
+
+    /**
+     * @param array $sortings
+     */
+    public function setSortings(array $sortings)
+    {
+        $this->sortings = $sortings;
+    }
+
+    /**
+     * @param Sorting $sorting
+     */
+    public function addSorting(Sorting $sorting)
+    {
+        $this->sortings[] = $sorting;
+    }
+
+    /**
+     * Parses a sortings representation "<fieldName> <direction>,<fieldName> <direction>"
+     * @param string $sortingsString
+     * @return Sortings
+     */
+    public static function fromString($sortingsString)
+    {
+        $sortFields = GeneralUtility::trimExplode(',',$sortingsString);
+        $sortings = [];
+        foreach($sortFields as $sortField) {
+            $sorting = Sorting::fromString($sortField);
+            $sortings[] = $sorting;
+        }
+
+        return new Sortings(true, $sortings);
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/Spellchecking.php

@@ -0,0 +1,102 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The Spellchecking ParameterProvider is responsible to build the solr query parameters
+ * that are needed for the spellchecking.
+ */
+class Spellchecking extends AbstractDeactivatable implements ParameterBuilder
+{
+
+    /**
+     * @var int
+     */
+    protected $maxCollationTries = 0;
+
+    /**
+     * Spellchecking constructor.
+     *
+     * @param bool $isEnabled
+     * @param int $maxCollationTries
+     */
+    public function __construct($isEnabled = false, int $maxCollationTries = 0)
+    {
+        $this->isEnabled = $isEnabled;
+        $this->maxCollationTries = $maxCollationTries;
+    }
+
+    /**
+     * @return int
+     */
+    public function getMaxCollationTries(): int
+    {
+        return $this->maxCollationTries;
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return Spellchecking
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getSearchSpellchecking();
+        if (!$isEnabled) {
+            return new Spellchecking(false);
+        }
+
+        $maxCollationTries = $solrConfiguration->getSearchSpellcheckingNumberOfSuggestionsToTry();
+
+        return new Spellchecking($isEnabled, $maxCollationTries);
+    }
+
+    /**
+     * @return Spellchecking
+     */
+    public static function getEmpty()
+    {
+        return new Spellchecking(false);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $query = $parentBuilder->getQuery();
+        if (!$this->getIsEnabled()) {
+            $query->removeComponent($query->getSpellcheck());
+            return $parentBuilder;
+        }
+
+        $query->getSpellcheck()->setMaxCollationTries($this->getMaxCollationTries());
+        $query->getSpellcheck()->setCollate(true);
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/ParameterBuilder/TrigramPhraseFields.php

@@ -0,0 +1,94 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2010-2017 dkd Internet Service GmbH <solr-support@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\AbstractQueryBuilder;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * The TrigramPhraseFields class
+ */
+class TrigramPhraseFields extends AbstractFieldList implements ParameterBuilder
+{
+    /**
+     * Parameter key which should be used for Apache Solr URL query
+     *
+     * @var string
+     */
+    protected $parameterKey = 'pf3';
+
+    /**
+     * Parses the string representation of the fieldList (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return TrigramPhraseFields
+     */
+    public static function fromString(string $fieldListString, string $delimiter = ',') : TrigramPhraseFields
+    {
+        return self::initializeFromString($fieldListString, $delimiter);
+    }
+
+    /**
+     * @param TypoScriptConfiguration $solrConfiguration
+     * @return TrigramPhraseFields
+     */
+    public static function fromTypoScriptConfiguration(TypoScriptConfiguration $solrConfiguration)
+    {
+        $isEnabled = $solrConfiguration->getTrigramPhraseSearchIsEnabled();
+        if (!$isEnabled) {
+            return new TrigramPhraseFields(false);
+        }
+
+        return self::fromString((string)$solrConfiguration->getSearchQueryTrigramPhraseFields());
+    }
+
+    /**
+     * Parses the string representation of the fieldList (e.g. content^100, title^10) to the object representation.
+     *
+     * @param string $fieldListString
+     * @param string $delimiter
+     * @return TrigramPhraseFields
+     */
+    protected static function initializeFromString(string $fieldListString, string $delimiter = ',') : TrigramPhraseFields
+    {
+        $fieldList = self::buildFieldList($fieldListString, $delimiter);
+        return new TrigramPhraseFields(true, $fieldList);
+    }
+
+    /**
+     * @param AbstractQueryBuilder $parentBuilder
+     * @return AbstractQueryBuilder
+     */
+    public function build(AbstractQueryBuilder $parentBuilder): AbstractQueryBuilder
+    {
+        $trigramPhraseFieldsString = $this->toString();
+        if ($trigramPhraseFieldsString === '' || !$this->getIsEnabled()) {
+            return $parentBuilder;
+        }
+        $parentBuilder->getQuery()->getEDisMax()->setPhraseTrigramFields($trigramPhraseFieldsString);
+        return $parentBuilder;
+    }
+}

Classes/Domain/Search/Query/Query.php

@@ -0,0 +1,47 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2009-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use Solarium\QueryType\Select\Query\Query as SolariumQuery;
+
+class Query extends SolariumQuery {
+
+    /**
+     * Returns the query parameters that should be used.
+     *
+     * @return array
+     */
+    public function getQueryParameters() {
+        return $this->getParams();
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString()
+    {
+        return $this->getQuery();
+    }
+}

Classes/Domain/Search/Query/QueryBuilder.php

@@ -0,0 +1,587 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017 <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\BigramPhraseFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Elevation;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Faceting;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\FieldCollapsing;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Filters;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Grouping;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Highlighting;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\PhraseFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\QueryFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\ReturnFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Slops;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Sorting;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Sortings;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\Spellchecking;
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\TrigramPhraseFields;
+use WapplerSystems\Meilisearch\Domain\Site\SiteHashService;
+use WapplerSystems\Meilisearch\Domain\Site\SiteRepository;
+use WapplerSystems\Meilisearch\FieldProcessor\PageUidToHierarchy;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\System\Logging\SolrLogManager;
+use WapplerSystems\Meilisearch\Util;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
+
+/**
+ * The concrete QueryBuilder contains all TYPO3 specific initialization logic of solr queries, for TYPO3.
+ */
+class QueryBuilder extends AbstractQueryBuilder {
+
+    /**
+     * Additional filters, which will be added to the query, as well as to
+     * suggest queries.
+     *
+     * @var array
+     */
+    protected $additionalFilters = [];
+
+    /**
+     * @var TypoScriptConfiguration
+     */
+    protected $typoScriptConfiguration = null;
+
+    /**
+     * @var SolrLogManager;
+     */
+    protected $logger = null;
+
+    /**
+     * @var SiteHashService
+     */
+    protected $siteHashService = null;
+
+    /**
+     * QueryBuilder constructor.
+     * @param TypoScriptConfiguration|null $configuration
+     * @param SolrLogManager|null $solrLogManager
+     * @param SiteHashService|null $siteHashService
+     */
+    public function __construct(TypoScriptConfiguration $configuration = null, SolrLogManager $solrLogManager = null, SiteHashService $siteHashService = null)
+    {
+        $this->typoScriptConfiguration = $configuration ?? Util::getSolrConfiguration();
+        $this->logger = $solrLogManager ?? GeneralUtility::makeInstance(SolrLogManager::class, /** @scrutinizer ignore-type */ __CLASS__);
+        $this->siteHashService = $siteHashService ?? GeneralUtility::makeInstance(SiteHashService::class);
+    }
+
+    /**
+     * @param string $queryString
+     * @return QueryBuilder
+     */
+    public function newSearchQuery($queryString): QueryBuilder
+    {
+        $this->queryToBuild = $this->getSearchQueryInstance((string)$queryString);
+        return $this;
+    }
+
+    /**
+     * @param string $queryString
+     * @return QueryBuilder
+     */
+    public function newSuggestQuery($queryString): QueryBuilder
+    {
+        $this->queryToBuild = $this->getSuggestQueryInstance($queryString);
+        return $this;
+    }
+
+    /**
+     * Initializes the Query object and SearchComponents and returns
+     * the initialized query object, when a search should be executed.
+     *
+     * @param string|null $rawQuery
+     * @param int $resultsPerPage
+     * @param array $additionalFiltersFromRequest
+     * @return SearchQuery
+     */
+    public function buildSearchQuery($rawQuery, $resultsPerPage = 10, array $additionalFiltersFromRequest = []) : SearchQuery
+    {
+        if ($this->typoScriptConfiguration->getLoggingQuerySearchWords()) {
+            $this->logger->log(SolrLogManager::INFO, 'Received search query', [$rawQuery]);
+        }
+
+        /* @var $query SearchQuery */
+        return $this->newSearchQuery($rawQuery)
+                ->useResultsPerPage($resultsPerPage)
+                ->useReturnFieldsFromTypoScript()
+                ->useQueryFieldsFromTypoScript()
+                ->useInitialQueryFromTypoScript()
+                ->useFiltersFromTypoScript()
+                ->useFilterArray($additionalFiltersFromRequest)
+                ->useFacetingFromTypoScript()
+                ->useVariantsFromTypoScript()
+                ->useGroupingFromTypoScript()
+                ->useHighlightingFromTypoScript()
+                ->usePhraseFieldsFromTypoScript()
+                ->useBigramPhraseFieldsFromTypoScript()
+                ->useTrigramPhraseFieldsFromTypoScript()
+                ->useOmitHeader(false)
+                ->getQuery();
+    }
+
+    /**
+     * Builds a SuggestQuery with all applied filters.
+     *
+     * @param string $queryString
+     * @param array $additionalFilters
+     * @param integer $requestedPageId
+     * @param string $groupList
+     * @return SuggestQuery
+     */
+    public function buildSuggestQuery(string $queryString, array $additionalFilters, int $requestedPageId, string $groupList) : SuggestQuery
+    {
+        $this->newSuggestQuery($queryString)
+            ->useFiltersFromTypoScript()
+            ->useSiteHashFromTypoScript($requestedPageId)
+            ->useUserAccessGroups(explode(',', $groupList))
+            ->useOmitHeader();
+
+
+        if (!empty($additionalFilters)) {
+            $this->useFilterArray($additionalFilters);
+        }
+
+        return $this->queryToBuild;
+    }
+
+    /**
+     * Returns Query for Search which finds document for given page.
+     * Note: The Connection is per language as recommended in ext-solr docs.
+     *
+     * @return Query
+     */
+    public function buildPageQuery($pageId)
+    {
+        $siteRepository = GeneralUtility::makeInstance(SiteRepository::class);
+        $site = $siteRepository->getSiteByPageId($pageId);
+
+        return $this->newSearchQuery('')
+            ->useQueryString('*:*')
+            ->useFilter('(type:pages AND uid:' . $pageId . ') OR (*:* AND pid:' . $pageId . ' NOT type:pages)', 'type')
+            ->useFilter('siteHash:' . $site->getSiteHash(), 'siteHash')
+            ->useReturnFields(ReturnFields::fromString('*'))
+            ->useSortings(Sortings::fromString('type asc, title asc'))
+            ->useQueryType('standard')
+            ->getQuery();
+    }
+
+    /**
+     * Returns a query for single record
+     *
+     * @return Query
+     */
+    public function buildRecordQuery($type, $uid, $pageId): Query
+    {
+        $siteRepository = GeneralUtility::makeInstance(SiteRepository::class);
+        $site = $siteRepository->getSiteByPageId($pageId);
+
+        return $this->newSearchQuery('')
+            ->useQueryString('*:*')
+            ->useFilter('type:' . $type . ' AND uid:' . $uid, 'type')
+            ->useFilter('siteHash:' . $site->getSiteHash(), 'siteHash')
+            ->useReturnFields(ReturnFields::fromString('*'))
+            ->useSortings(Sortings::fromString('type asc, title asc'))
+            ->useQueryType('standard')
+            ->getQuery();
+    }
+
+    /**
+     * @return QueryBuilder
+     */
+    public function useSlopsFromTypoScript(): QueryBuilder
+    {
+        return $this->useSlops(Slops::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Uses the configured boost queries from typoscript
+     *
+     * @return QueryBuilder
+     */
+    public function useBoostQueriesFromTypoScript(): QueryBuilder
+    {
+        $searchConfiguration = $this->typoScriptConfiguration->getSearchConfiguration();
+
+        if (!empty($searchConfiguration['query.']['boostQuery'])) {
+            return $this->useBoostQueries($searchConfiguration['query.']['boostQuery']);
+        }
+
+        if (!empty($searchConfiguration['query.']['boostQuery.'])) {
+            $boostQueries = $searchConfiguration['query.']['boostQuery.'];
+            return $this->useBoostQueries(array_values($boostQueries));
+        }
+
+        return $this;
+    }
+
+    /**
+     * Uses the configured boostFunction from the typoscript configuration.
+     *
+     * @return QueryBuilder
+     */
+    public function useBoostFunctionFromTypoScript(): QueryBuilder
+    {
+        $searchConfiguration = $this->typoScriptConfiguration->getSearchConfiguration();
+        if (!empty($searchConfiguration['query.']['boostFunction'])) {
+            return $this->useBoostFunction($searchConfiguration['query.']['boostFunction']);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Uses the configured minimumMatch from the typoscript configuration.
+     *
+     * @return QueryBuilder
+     */
+    public function useMinimumMatchFromTypoScript(): QueryBuilder
+    {
+        $searchConfiguration = $this->typoScriptConfiguration->getSearchConfiguration();
+        if (!empty($searchConfiguration['query.']['minimumMatch'])) {
+            return $this->useMinimumMatch($searchConfiguration['query.']['minimumMatch']);
+        }
+
+        return $this;
+    }
+
+    /**
+     * @return QueryBuilder
+     */
+    public function useTieParameterFromTypoScript(): QueryBuilder
+    {
+        $searchConfiguration = $this->typoScriptConfiguration->getSearchConfiguration();
+        if (empty($searchConfiguration['query.']['tieParameter'])) {
+            return $this;
+        }
+
+        return $this->useTieParameter($searchConfiguration['query.']['tieParameter']);
+    }
+
+    /**
+     * Applies the configured query fields from the typoscript configuration.
+     *
+     * @return QueryBuilder
+     */
+    public function useQueryFieldsFromTypoScript(): QueryBuilder
+    {
+        return $this->useQueryFields(QueryFields::fromString($this->typoScriptConfiguration->getSearchQueryQueryFields()));
+    }
+
+    /**
+     * Applies the configured return fields from the typoscript configuration.
+     *
+     * @return QueryBuilder
+     */
+    public function useReturnFieldsFromTypoScript(): QueryBuilder
+    {
+        $returnFieldsArray = (array)$this->typoScriptConfiguration->getSearchQueryReturnFieldsAsArray(['*', 'score']);
+        return $this->useReturnFields(ReturnFields::fromArray($returnFieldsArray));
+    }
+
+
+
+    /**
+     * Can be used to apply the allowed sites from plugin.tx_meilisearch.search.query.allowedSites to the query.
+     *
+     * @param int $requestedPageId
+     * @return QueryBuilder
+     */
+    public function useSiteHashFromTypoScript(int $requestedPageId): QueryBuilder
+    {
+        $queryConfiguration = $this->typoScriptConfiguration->getObjectByPathOrDefault('plugin.tx_meilisearch.search.query.', []);
+        $allowedSites = $this->siteHashService->getAllowedSitesForPageIdAndAllowedSitesConfiguration($requestedPageId, $queryConfiguration['allowedSites']);
+        return $this->useSiteHashFromAllowedSites($allowedSites);
+    }
+
+    /**
+     * Can be used to apply a list of allowed sites to the query.
+     *
+     * @param string $allowedSites
+     * @return QueryBuilder
+     */
+    public function useSiteHashFromAllowedSites($allowedSites): QueryBuilder
+    {
+        $isAnySiteAllowed = trim($allowedSites) === '*';
+        if ($isAnySiteAllowed) {
+            // no filter required
+            return $this;
+        }
+
+        $allowedSites = GeneralUtility::trimExplode(',', $allowedSites);
+        $filters = [];
+        foreach ($allowedSites as $site) {
+            $siteHash = $this->siteHashService->getSiteHashForDomain($site);
+            $filters[] = 'siteHash:"' . $siteHash . '"';
+        }
+
+        $siteHashFilterString = implode(' OR ', $filters);
+        return $this->useFilter($siteHashFilterString, 'siteHash');
+    }
+
+    /**
+     * Can be used to filter the result on an applied list of user groups.
+     *
+     * @param array $groups
+     * @return QueryBuilder
+     */
+    public function useUserAccessGroups(array $groups): QueryBuilder
+    {
+        $groups = array_map('intval', $groups);
+        $groups[] = 0; // always grant access to public documents
+        $groups = array_unique($groups);
+        sort($groups, SORT_NUMERIC);
+
+        $accessFilter = '{!typo3access}' . implode(',', $groups);
+        $this->queryToBuild->removeFilterQuery('access');
+        return $this->useFilter($accessFilter, 'access');
+    }
+
+    /**
+     * Applies the configured initial query settings to set the alternative query for solr as required.
+     *
+     * @return QueryBuilder
+     */
+    public function useInitialQueryFromTypoScript(): QueryBuilder
+    {
+        if ($this->typoScriptConfiguration->getSearchInitializeWithEmptyQuery() || $this->typoScriptConfiguration->getSearchQueryAllowEmptyQuery()) {
+            // empty main query, but using a "return everything"
+            // alternative query in q.alt
+            $this->useAlternativeQuery('*:*');
+        }
+
+        if ($this->typoScriptConfiguration->getSearchInitializeWithQuery()) {
+            $this->useAlternativeQuery($this->typoScriptConfiguration->getSearchInitializeWithQuery());
+        }
+
+        return $this;
+    }
+
+    /**
+     * Applies the configured facets from the typoscript configuration on the query.
+     *
+     * @return QueryBuilder
+     */
+    public function useFacetingFromTypoScript(): QueryBuilder
+    {
+        return $this->useFaceting(Faceting::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured variants from the typoscript configuration on the query.
+     *
+     * @return QueryBuilder
+     */
+    public function useVariantsFromTypoScript(): QueryBuilder
+    {
+        return $this->useFieldCollapsing(FieldCollapsing::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured groupings from the typoscript configuration to the query.
+     *
+     * @return QueryBuilder
+     */
+    public function useGroupingFromTypoScript(): QueryBuilder
+    {
+        return $this->useGrouping(Grouping::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured highlighting from the typoscript configuration to the query.
+     *
+     * @return QueryBuilder
+     */
+    public function useHighlightingFromTypoScript(): QueryBuilder
+    {
+        return $this->useHighlighting(Highlighting::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured filters (page section and other from typoscript).
+     *
+     * @return QueryBuilder
+     */
+    public function useFiltersFromTypoScript(): QueryBuilder
+    {
+        $filters = Filters::fromTypoScriptConfiguration($this->typoScriptConfiguration);
+        $this->queryToBuild->setFilterQueries($filters->getValues());
+
+        $this->useFilterArray($this->getAdditionalFilters());
+
+        $searchQueryFilters = $this->typoScriptConfiguration->getSearchQueryFilterConfiguration();
+
+        if (!is_array($searchQueryFilters) || count($searchQueryFilters) <= 0) {
+            return $this;
+        }
+
+        // special filter to limit search to specific page tree branches
+        if (array_key_exists('__pageSections', $searchQueryFilters)) {
+            $pageIds = GeneralUtility::trimExplode(',', $searchQueryFilters['__pageSections']);
+            $this->usePageSectionsFromPageIds($pageIds);
+            $this->typoScriptConfiguration->removeSearchQueryFilterForPageSections();
+        }
+
+        return $this;
+    }
+
+    /**
+     * Applies the configured elevation from the typoscript configuration.
+     *
+     * @return QueryBuilder
+     */
+    public function useElevationFromTypoScript(): QueryBuilder
+    {
+        return $this->useElevation(Elevation::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured spellchecking from the typoscript configuration.
+     *
+     * @return QueryBuilder
+     */
+    public function useSpellcheckingFromTypoScript(): QueryBuilder
+    {
+        return $this->useSpellchecking(Spellchecking::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the passed pageIds as __pageSection filter.
+     *
+     * @param array $pageIds
+     * @return QueryBuilder
+     */
+    public function usePageSectionsFromPageIds(array $pageIds = []): QueryBuilder
+    {
+        $filters = [];
+
+        /** @var $processor PageUidToHierarchy */
+        $processor = GeneralUtility::makeInstance(PageUidToHierarchy::class);
+        $hierarchies = $processor->process($pageIds);
+
+        foreach ($hierarchies as $hierarchy) {
+            $lastLevel = array_pop($hierarchy);
+            $filters[] = 'rootline:"' . $lastLevel . '"';
+        }
+
+        $pageSectionsFilterString = implode(' OR ', $filters);
+        return $this->useFilter($pageSectionsFilterString, 'pageSections');
+    }
+
+    /**
+     * Applies the configured phrase fields from the typoscript configuration to the query.
+     *
+     * @return QueryBuilder
+     */
+    public function usePhraseFieldsFromTypoScript(): QueryBuilder
+    {
+        return $this->usePhraseFields(PhraseFields::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured bigram phrase fields from the typoscript configuration to the query.
+     *
+     * @return QueryBuilder
+     */
+    public function useBigramPhraseFieldsFromTypoScript(): QueryBuilder
+    {
+        return $this->useBigramPhraseFields(BigramPhraseFields::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Applies the configured trigram phrase fields from the typoscript configuration to the query.
+     *
+     * @return QueryBuilder
+     */
+    public function useTrigramPhraseFieldsFromTypoScript(): QueryBuilder
+    {
+        return $this->useTrigramPhraseFields(TrigramPhraseFields::fromTypoScriptConfiguration($this->typoScriptConfiguration));
+    }
+
+    /**
+     * Retrieves the configuration filters from the TypoScript configuration, except the __pageSections filter.
+     *
+     * @return array
+     */
+    public function getAdditionalFilters() : array
+    {
+        // when we've build the additionalFilter once, we could return them
+        if (count($this->additionalFilters) > 0) {
+            return $this->additionalFilters;
+        }
+
+        $searchQueryFilters = $this->typoScriptConfiguration->getSearchQueryFilterConfiguration();
+        if (!is_array($searchQueryFilters) || count($searchQueryFilters) <= 0) {
+            return [];
+        }
+
+        $cObj = GeneralUtility::makeInstance(ContentObjectRenderer::class);
+
+        // all other regular filters
+        foreach ($searchQueryFilters as $filterKey => $filter) {
+            // the __pageSections filter should not be handled as additional filter
+            if ($filterKey === '__pageSections') {
+                continue;
+            }
+
+            $filterIsArray = is_array($searchQueryFilters[$filterKey]);
+            if ($filterIsArray) {
+                continue;
+            }
+
+            $hasSubConfiguration = is_array($searchQueryFilters[$filterKey . '.']);
+            if ($hasSubConfiguration) {
+                $filter = $cObj->stdWrap($searchQueryFilters[$filterKey], $searchQueryFilters[$filterKey . '.']);
+            }
+
+            $this->additionalFilters[$filterKey] = $filter;
+        }
+
+        return $this->additionalFilters;
+    }
+
+    /**
+     * @param string $rawQuery
+     * @return SearchQuery
+     */
+    protected function getSearchQueryInstance(string $rawQuery): SearchQuery
+    {
+        $query = GeneralUtility::makeInstance(SearchQuery::class);
+        $query->setQuery($rawQuery);
+        return $query;
+    }
+
+    /**
+     * @param string $rawQuery
+     * @return SuggestQuery
+     */
+    protected function getSuggestQueryInstance($rawQuery): SuggestQuery
+    {
+        $query = GeneralUtility::makeInstance(SuggestQuery::class, /** @scrutinizer ignore-type */ $rawQuery, /** @scrutinizer ignore-type */ $this->typoScriptConfiguration);
+
+        return $query;
+    }
+}

Classes/Domain/Search/Query/SearchQuery.php

@@ -0,0 +1,27 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2009-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+class SearchQuery extends Query {}

Classes/Domain/Search/Query/SuggestQuery.php

@@ -0,0 +1,86 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\Query;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2009-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\Query\ParameterBuilder\ReturnFields;
+use WapplerSystems\Meilisearch\Domain\Search\Query\Helper\EscapeService;
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+use WapplerSystems\Meilisearch\Util;
+
+/**
+ * A query specialized to get search suggestions
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class SuggestQuery extends Query
+{
+    /**
+     * @var array
+     */
+    protected $configuration;
+
+    /**
+     * @var string
+     */
+    protected $prefix;
+
+    /**
+     * SuggestQuery constructor.
+     *
+     * @param string $keywords
+     * @param TypoScriptConfiguration $solrConfiguration
+     */
+    public function __construct($keywords, $solrConfiguration = null)
+    {
+        parent::__construct();
+        $keywords = (string)$keywords;
+
+        $solrConfiguration = $solrConfiguration ?? Util::getSolrConfiguration();
+
+        $this->setQuery($keywords);
+        $this->configuration = $solrConfiguration->getObjectByPathOrDefault('plugin.tx_meilisearch.suggest.', []);
+
+        if (!empty($this->configuration['treatMultipleTermsAsSingleTerm'])) {
+            $this->prefix = EscapeService::escape($keywords);
+        } else {
+            $matches = [];
+            preg_match('/^(:?(.* |))([^ ]+)$/', $keywords, $matches);
+            $fullKeywords = trim($matches[2]);
+            $partialKeyword = trim($matches[3]);
+
+            $this->setQuery($fullKeywords);
+            $this->prefix = EscapeService::escape($partialKeyword);
+        }
+
+        $this->getEDisMax()->setQueryAlternative('*:*');
+        $this->setFields(ReturnFields::fromString($this->configuration['suggestField'])->getValues());
+        $this->addParam('facet', 'on');
+        $this->addParam('facet.prefix', $this->prefix);
+        $this->addParam('facet.field', $this->configuration['suggestField']);
+        $this->addParam('facet.limit', $this->configuration['numberOfSuggestions']);
+        $this->addParam('facet.mincount', 1);
+        $this->addParam('facet.method', 'enum');
+    }
+}

Classes/Domain/Search/ResultSet/Facets/AbstractFacet.php

@@ -0,0 +1,290 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+
+/**
+ * Value object that represent a options facet.
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+abstract class AbstractFacet
+{
+    const TYPE_ABSTRACT = 'abstract';
+
+    /**
+     * String
+     * @var string
+     */
+    protected static $type = self::TYPE_ABSTRACT;
+
+    /**
+     * The resultSet where this facet belongs to.
+     *
+     * @var SearchResultSet
+     */
+    protected $resultSet = null;
+
+    /**
+     * @var string
+     */
+    protected $name;
+
+    /**
+     * @var string
+     */
+    protected $field;
+
+    /**
+     * @var string
+     */
+    protected $label;
+
+    /**
+     * @var array
+     */
+    protected $configuration;
+
+    /**
+     * @var boolean
+     */
+    protected $isAvailable = false;
+
+    /**
+     * @var bool
+     */
+    protected $isUsed = false;
+
+    /**
+     * @var bool
+     */
+    protected $allRequirementsMet = true;
+
+    /**
+     * @var \TYPO3\CMS\Extbase\Object\ObjectManagerInterface
+     */
+    protected $objectManager;
+
+    /**
+     * AbstractFacet constructor.
+     *
+     * @param SearchResultSet $resultSet
+     * @param string $name
+     * @param string $field
+     * @param string $label
+     * @param array $configuration Facet configuration passed from typoscript
+     */
+    public function __construct(SearchResultSet $resultSet, $name, $field, $label = '', array $configuration = [])
+    {
+        $this->resultSet = $resultSet;
+        $this->name = $name;
+        $this->field = $field;
+        $this->label = $label;
+        $this->configuration = $configuration;
+    }
+
+    /**
+     * Injects the object manager
+     *
+     * @param \TYPO3\CMS\Extbase\Object\ObjectManagerInterface $objectManager
+     */
+    public function injectObjectManager(\TYPO3\CMS\Extbase\Object\ObjectManagerInterface $objectManager)
+    {
+        $this->objectManager = $objectManager;
+    }
+
+    /**
+     * Get name
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Get solr field name
+     *
+     * @return string
+     */
+    public function getField()
+    {
+        return $this->field;
+    }
+
+    /**
+     * @param string $label
+     */
+    public function setLabel($label)
+    {
+        $this->label = $label;
+    }
+
+    /**
+     * @return string
+     */
+    public function getLabel()
+    {
+        return $this->label;
+    }
+
+    /**
+     * @param boolean $isAvailable
+     */
+    public function setIsAvailable($isAvailable)
+    {
+        $this->isAvailable = $isAvailable;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getIsAvailable()
+    {
+        return $this->isAvailable;
+    }
+
+    /**
+     * @param boolean $isUsed
+     */
+    public function setIsUsed($isUsed)
+    {
+        $this->isUsed = $isUsed;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getIsUsed()
+    {
+        return $this->isUsed;
+    }
+
+    /**
+     * @return string
+     */
+    public function getType()
+    {
+        return static::$type;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getAllRequirementsMet()
+    {
+        return $this->allRequirementsMet;
+    }
+
+    /**
+     * @param boolean $allRequirementsMet
+     */
+    public function setAllRequirementsMet($allRequirementsMet)
+    {
+        $this->allRequirementsMet = $allRequirementsMet;
+    }
+
+    /**
+     * @return SearchResultSet
+     */
+    public function getResultSet()
+    {
+        return $this->resultSet;
+    }
+
+    /**
+     * Get configuration
+     *
+     * @return mixed
+     */
+    public function getConfiguration()
+    {
+        return $this->configuration;
+    }
+
+    /**
+     * Get facet partial name used for rendering the facet
+     *
+     * @return string
+     */
+    public function getPartialName()
+    {
+        return 'Default';
+    }
+
+    /**
+     * @return string
+     */
+    public function getGroupName()
+    {
+        return isset($this->configuration['groupName']) ? $this->configuration['groupName'] : 'main';
+    }
+
+    /**
+     * Indicates if this facet should ne included in the available facets. When nothing is configured,
+     * the method return TRUE.
+     *
+     * @return boolean
+     */
+    public function getIncludeInAvailableFacets()
+    {
+        return ((int)$this->getFacetSettingOrDefaultValue('includeInAvailableFacets', 1)) === 1;
+    }
+
+    /**
+     * Indicates if this facets should be included in the used facets. When nothing is configured,
+     * the methods returns true.
+     *
+     * @return boolean
+     */
+    public function getIncludeInUsedFacets()
+    {
+
+        return ((int)$this->getFacetSettingOrDefaultValue('includeInUsedFacets', 1)) === 1;
+    }
+
+    /**
+     * Returns the configured requirements
+     *
+     * @return array
+     */
+    public function getRequirements()
+    {
+        return $this->getFacetSettingOrDefaultValue('requirements.', []);
+    }
+
+    /**
+     * The implementation of this method should return a "flatten" collection of all items.
+     *
+     * @return AbstractFacetItemCollection
+     */
+    abstract public function getAllFacetItems();
+
+    /**
+     * @param string $key
+     * @param mixed $defaultValue
+     * @return mixed
+     */
+    protected function getFacetSettingOrDefaultValue($key, $defaultValue)
+    {
+        if (!isset($this->configuration[$key])) {
+            return $defaultValue;
+        }
+
+        return ($this->configuration[$key]);
+    }
+}

Classes/Domain/Search/ResultSet/Facets/AbstractFacetItem.php

@@ -0,0 +1,116 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+
+/**
+ * Abstract item that represent a value of a facet. E.g. an option or a node
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+abstract class AbstractFacetItem
+{
+    /**
+     * @var string
+     */
+    protected $label = '';
+
+    /**
+     * @var int
+     */
+    protected $documentCount = 0;
+
+    /**
+     * @var bool
+     */
+    protected $selected = false;
+
+    /**
+     * @var array
+     */
+    protected $metrics = [];
+
+    /**
+     * @var AbstractFacet
+     */
+    protected $facet;
+
+    /**
+     * @param AbstractFacet $facet
+     * @param string $label
+     * @param int $documentCount
+     * @param bool $selected
+     * @param array $metrics
+     */
+    public function __construct(AbstractFacet $facet, $label = '', $documentCount = 0, $selected = false, $metrics = [])
+    {
+        $this->facet = $facet;
+        $this->label = $label;
+        $this->documentCount = $documentCount;
+        $this->selected = $selected;
+        $this->metrics = $metrics;
+    }
+
+    /**
+     * @return int
+     */
+    public function getDocumentCount()
+    {
+        return $this->documentCount;
+    }
+
+    /**
+     * @return \WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacet
+     */
+    public function getFacet()
+    {
+        return $this->facet;
+    }
+
+    /**
+     * @return string
+     */
+    public function getLabel()
+    {
+        return $this->label;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getSelected()
+    {
+        return $this->selected;
+    }
+
+    /**
+     * @return array
+     */
+    public function getMetrics()
+    {
+        return $this->metrics;
+    }
+
+    /**
+     * @return string
+     */
+    abstract public function getUriValue();
+
+    /**
+     * @return string
+     */
+    abstract function getCollectionKey();
+}

Classes/Domain/Search/ResultSet/Facets/AbstractFacetItemCollection.php

@@ -0,0 +1,102 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetItem;
+use WapplerSystems\Meilisearch\System\Data\AbstractCollection;
+
+/**
+ * Collection for facet options.
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+abstract class AbstractFacetItemCollection extends AbstractCollection
+{
+    /**
+     * @param AbstractFacetItem $item
+     * @return AbstractFacetItemCollection
+     */
+    public function add($item)
+    {
+        if ($item === null) {
+            return $this;
+        }
+
+        $this->data[$item->getCollectionKey()] = $item;
+        return $this;
+    }
+
+    /**
+     * @param string $value
+     * @return AbstractFacetItem
+     */
+    public function getByValue($value)
+    {
+        return isset($this->data[$value]) ? $this->data[$value] : null;
+    }
+
+    /**
+     * Retrieves the count (with get prefixed to be usable in fluid).
+     *
+     * @return int
+     */
+    public function getCount()
+    {
+        return $this->count();
+    }
+
+    /**
+     * @return AbstractFacetItemCollection
+     */
+    public function getSelected()
+    {
+        return $this->getFilteredCopy(function(AbstractFacetItem $item) {
+            return $item->getSelected();
+        });
+    }
+
+    /**
+     * @param array $manualSorting
+     * @return AbstractFacetItemCollection
+     */
+    public function getManualSortedCopy(array $manualSorting)
+    {
+        $result = clone $this;
+        $copiedItems = $result->data;
+        $sortedOptions = [];
+        foreach ($manualSorting as $item) {
+            if (isset($copiedItems[$item])) {
+                $sortedOptions[$item] = $copiedItems[$item];
+                unset($copiedItems[$item]);
+            }
+        }
+        // in the end all items get appended that are not configured in the manual sort order
+        $sortedOptions = $sortedOptions + $copiedItems;
+        $result->data = $sortedOptions;
+
+        return $result;
+    }
+
+    /**
+     * @return AbstractFacetItemCollection
+     */
+    public function getReversedOrderCopy()
+    {
+        $result = clone $this;
+        $result->data = array_reverse($result->data, true);
+
+        return $result;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/AbstractFacetPackage.php

@@ -0,0 +1,92 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+use TYPO3\CMS\Extbase\Object\ObjectManagerInterface;
+
+/**
+ * Class AbstractFacetPackage
+ */
+abstract class AbstractFacetPackage {
+    /**
+     * @var ObjectManagerInterface
+     */
+    protected $objectManager;
+
+    /**
+     * @param ObjectManagerInterface $objectManager
+     */
+    public function setObjectManager(ObjectManagerInterface $objectManager)
+    {
+        $this->objectManager = $objectManager;
+    }
+
+    /**
+     * @return string
+     */
+    abstract public function getParserClassName();
+
+    /**
+     * @return FacetParserInterface
+     * @throws InvalidFacetPackageException
+     */
+    public function getParser()
+    {
+        $parser = $this->objectManager->get($this->getParserClassName());
+        if (!$parser instanceof FacetParserInterface) {
+            throw new InvalidFacetPackageException('Invalid parser for package ' . __CLASS__);
+        }
+        return $parser;
+    }
+
+    /**
+     * @return string
+     */
+    public function getUrlDecoderClassName() {
+        return (string)DefaultUrlDecoder::class;
+    }
+
+    /**
+     * @throws InvalidUrlDecoderException
+     * @return FacetUrlDecoderInterface
+     */
+    public function getUrlDecoder()
+    {
+        $urlDecoder = $this->objectManager->get($this->getUrlDecoderClassName());
+        if (!$urlDecoder instanceof FacetUrlDecoderInterface) {
+            throw new InvalidUrlDecoderException('Invalid urldecoder for package ' . __CLASS__);
+        }
+        return $urlDecoder;
+    }
+
+    /**
+     * @return string
+     */
+    public function getQueryBuilderClassName() {
+        return (string)DefaultFacetQueryBuilder::class;
+    }
+
+    /**
+     * @throws InvalidQueryBuilderException
+     * @return FacetQueryBuilderInterface
+     */
+    public function getQueryBuilder()
+    {
+        $urlDecoder = $this->objectManager->get($this->getQueryBuilderClassName());
+        if(!$urlDecoder instanceof FacetQueryBuilderInterface) {
+            throw new InvalidQueryBuilderException('Invalid querybuilder for package ' . __CLASS__);
+        }
+        return $urlDecoder;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/AbstractFacetParser.php

@@ -0,0 +1,189 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\AbstractOptionsFacet;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Object\ObjectManagerInterface;
+use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
+
+/**
+ * Class AbstractFacetParser
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+abstract class AbstractFacetParser implements FacetParserInterface
+{
+    /**
+     * @var ContentObjectRenderer
+     */
+    protected static $reUseAbleContentObject;
+
+    /**
+     * @var ObjectManagerInterface
+     */
+    protected $objectManager;
+
+    /**
+     * @param ObjectManagerInterface $objectManager
+     */
+    public function injectObjectManager(ObjectManagerInterface $objectManager)
+    {
+        $this->objectManager = $objectManager;
+    }
+
+    /**
+     * @return ContentObjectRenderer
+     */
+    protected function getReUseAbleContentObject()
+    {
+        /** @var $contentObject ContentObjectRenderer */
+        if (self::$reUseAbleContentObject !== null) {
+            return self::$reUseAbleContentObject;
+        }
+
+        self::$reUseAbleContentObject = GeneralUtility::makeInstance(ContentObjectRenderer::class);
+        return self::$reUseAbleContentObject;
+    }
+
+    /**
+     * @param array $configuration
+     * @return string
+     */
+    protected function getPlainLabelOrApplyCObject($configuration)
+    {
+        // when no label is configured we return an empty string
+        if (!isset($configuration['label'])) {
+            return '';
+        }
+
+        // when no sub configuration is set, we use the string, configured as label
+        if (!isset($configuration['label.'])) {
+            return $configuration['label'];
+        }
+
+        // when label and label. was set, we apply the cObject
+        return $this->getReUseAbleContentObject()->cObjGetSingle($configuration['label'], $configuration['label.']);
+    }
+
+    /**
+     * @param mixed $value
+     * @param integer $count
+     * @param string $facetName
+     * @param array $facetConfiguration
+     * @return string
+     */
+    protected function getLabelFromRenderingInstructions($value, $count, $facetName, $facetConfiguration)
+    {
+        $hasRenderingInstructions = isset($facetConfiguration['renderingInstruction']) && isset($facetConfiguration['renderingInstruction.']);
+        if (!$hasRenderingInstructions) {
+            return $value;
+        }
+
+        $this->getReUseAbleContentObject()->start(['optionValue' => $value, 'optionCount' => $count, 'facetName' => $facetName]);
+        return $this->getReUseAbleContentObject()->cObjGetSingle(
+            $facetConfiguration['renderingInstruction'],
+            $facetConfiguration['renderingInstruction.']
+        );
+    }
+
+
+    /**
+     * Retrieves the active facetValue for a facet from the search request.
+     * @param SearchResultSet $resultSet
+     * @param string $facetName
+     * @return array
+     */
+    protected function getActiveFacetValuesFromRequest(SearchResultSet $resultSet, $facetName)
+    {
+        $activeFacetValues = $resultSet->getUsedSearchRequest()->getActiveFacetValuesByName($facetName);
+        $activeFacetValues = is_array($activeFacetValues) ? $activeFacetValues : [];
+
+        return $activeFacetValues;
+    }
+
+
+    /**
+     * @param array $facetValuesFromSolrResponse
+     * @param array $facetValuesFromSearchRequest
+     * @return mixed
+     */
+    protected function getMergedFacetValueFromSearchRequestAndSolrResponse($facetValuesFromSolrResponse, $facetValuesFromSearchRequest)
+    {
+        $facetValueItemsToCreate = $facetValuesFromSolrResponse;
+
+        foreach ($facetValuesFromSearchRequest as $valueFromRequest) {
+            // if we have options in the request that have not been in the response we add them with a count of 0
+            if (!isset($facetValueItemsToCreate[$valueFromRequest])) {
+                $facetValueItemsToCreate[$valueFromRequest] = 0;
+            }
+        }
+        return $facetValueItemsToCreate;
+    }
+
+    /**
+     * @param AbstractOptionsFacet $facet
+     * @param array $facetConfiguration
+     * @return AbstractOptionsFacet
+     */
+    protected function applyManualSortOrder(AbstractOptionsFacet $facet, array $facetConfiguration)
+    {
+        if (!isset($facetConfiguration['manualSortOrder'])) {
+            return $facet;
+        }
+        $fields = GeneralUtility::trimExplode(',', $facetConfiguration['manualSortOrder']);
+        // @extensionScannerIgnoreLine
+        $sortedOptions = $facet->getOptions()->getManualSortedCopy($fields);
+
+        // @extensionScannerIgnoreLine
+        $facet->setOptions($sortedOptions);
+
+        return $facet;
+    }
+
+    /**
+     * @param AbstractOptionsFacet $facet
+     * @param array $facetConfiguration
+     * @return AbstractOptionsFacet
+     */
+    protected function applyReverseOrder(AbstractOptionsFacet $facet, array $facetConfiguration)
+    {
+        if (empty($facetConfiguration['reverseOrder'])) {
+            return $facet;
+        }
+
+        // @extensionScannerIgnoreLine
+        $facet->setOptions($facet->getOptions()->getReversedOrderCopy());
+
+        return $facet;
+    }
+
+    /**
+     * @param mixed $value
+     * @param array $facetConfiguration
+     * @return boolean
+     */
+    protected function getIsExcludedFacetValue($value, array $facetConfiguration)
+    {
+        if (!isset($facetConfiguration['excludeValues'])) {
+            return false;
+        }
+
+        $excludedValue = GeneralUtility::trimExplode(',', $facetConfiguration['excludeValues']);
+        return in_array($value, $excludedValue);
+    }
+}

Classes/Domain/Search/ResultSet/Facets/DefaultFacetQueryBuilder.php

@@ -0,0 +1,65 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+*/
+
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+class DefaultFacetQueryBuilder implements FacetQueryBuilderInterface {
+
+    /**
+     * @param string $facetName
+     * @param TypoScriptConfiguration $configuration
+     * @return array
+     */
+    public function build($facetName, TypoScriptConfiguration $configuration)
+    {
+        $facetParameters = [];
+        $facetConfiguration = $configuration->getSearchFacetingFacetByName($facetName);
+
+        $tags = $this->buildExcludeTags($facetConfiguration, $configuration);
+        $facetParameters['facet.field'][] = $tags . $facetConfiguration['field'];
+
+        $sortingExpression = new SortingExpression();
+        $facetSortExpression = $sortingExpression->getForFacet($facetConfiguration['sortBy']);
+        if (!empty($facetSortExpression)) {
+            $facetParameters['f.' . $facetConfiguration['field'] . '.facet.sort'] = $facetSortExpression;
+        }
+
+        return $facetParameters;
+    }
+
+    /**
+     * @param array $facetConfiguration
+     * @param TypoScriptConfiguration $configuration
+     * @return string
+     */
+    protected function buildExcludeTags(array $facetConfiguration, TypoScriptConfiguration $configuration)
+    {
+        // simple for now, may add overrides f.<field_name>.facet.* later
+        if ($configuration->getSearchFacetingKeepAllFacetsOnSelection()) {
+            $facets = [];
+            foreach ($configuration->getSearchFacetingFacets() as $facet) {
+                $facets[] = $facet['field'];
+            }
+
+            return '{!ex=' . implode(',', $facets) . '}';
+        } elseif ($facetConfiguration['keepAllOptionsOnSelection'] == 1) {
+            return '{!ex=' . $facetConfiguration['field'] . '}';
+        }
+
+        return '';
+    }
+}
+

Classes/Domain/Search/ResultSet/Facets/DefaultUrlDecoder.php

@@ -0,0 +1,31 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+*/
+
+class DefaultUrlDecoder implements FacetUrlDecoderInterface {
+
+    /**
+     * Parses the query filter from GET parameters in the URL and translates it
+     * to a Lucene filter value.
+     *
+     * @param string $value the filter query from plugin
+     * @param array $configuration Facet configuration
+     * @return string Value to be used in a Lucene filter
+     */
+    public function decode($value, array $configuration = [])
+    {
+        return '"' . addslashes($value) . '"';
+    }
+}

Classes/Domain/Search/ResultSet/Facets/FacetCollection.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+use WapplerSystems\Meilisearch\System\Data\AbstractCollection;
+
+/**
+ * Class FacetCollection
+ */
+class FacetCollection extends AbstractCollection
+{
+
+    /**
+     * @param AbstractFacet $facet
+     */
+    public function addFacet(AbstractFacet $facet)
+    {
+        $this->data[$facet->getName()] = $facet;
+    }
+
+    /**
+     * @return FacetCollection
+     */
+    public function getUsed()
+    {
+        return $this->getFilteredCopy(
+            function(AbstractFacet $facet) {
+                return $facet->getIsUsed() && $facet->getIncludeInUsedFacets();
+            }
+        );
+    }
+
+    /**
+     * @return FacetCollection
+     */
+    public function getAvailable()
+    {
+        return $this->getFilteredCopy(
+            function(AbstractFacet $facet) {
+                return $facet->getIsAvailable() && $facet->getIncludeInAvailableFacets() && $facet->getAllRequirementsMet();
+            }
+        );
+    }
+
+    /**
+     * @param string $requiredGroup
+     * @return AbstractCollection
+     */
+    public function getByGroupName($requiredGroup = 'all')
+    {
+        return $this->getFilteredCopy(
+            function(AbstractFacet $facet) use ($requiredGroup) {
+                return $facet->getGroupName() == $requiredGroup;
+            }
+        );
+    }
+
+    /**
+     * @param string $requiredName
+     * @return AbstractCollection
+     */
+    public function getByName($requiredName) {
+        return $this->getFilteredCopy(
+            function(AbstractFacet $facet) use ($requiredName) {
+                return $facet->getName() == $requiredName;
+            }
+        );
+    }
+
+    /**
+     * @param int $position
+     * @return AbstractFacet
+     */
+    public function getByPosition($position)
+    {
+        return parent::getByPosition($position);
+    }
+}

Classes/Domain/Search/ResultSet/Facets/FacetParserInterface.php

@@ -0,0 +1,34 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+
+/**
+ * Interface FacetParserInterface
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+interface FacetParserInterface
+{
+    /**
+     * @param SearchResultSet $resultSet
+     * @param string $facetName
+     * @param array $facetConfiguration
+     * @return AbstractFacet|null
+     */
+    public function parse(SearchResultSet $resultSet, $facetName, array $facetConfiguration);
+}

Classes/Domain/Search/ResultSet/Facets/FacetQueryBuilderInterface.php

@@ -0,0 +1,41 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2012-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+use WapplerSystems\Meilisearch\System\Configuration\TypoScriptConfiguration;
+
+/**
+ * Query Filter Encoder Interface
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+interface FacetQueryBuilderInterface
+{
+    /**
+     * @param string $facetName
+     * @param TypoScriptConfiguration $configuration
+     * @return array
+     */
+    public function build($facetName, TypoScriptConfiguration $configuration);
+}

Classes/Domain/Search/ResultSet/Facets/FacetRegistry.php

@@ -0,0 +1,108 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy\HierarchyPackage;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Options\OptionsPackage;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\QueryGroup\QueryGroupPackage;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\RangeBased\DateRange\DateRangePackage;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\RangeBased\NumericRange\NumericRangePackage;
+use WapplerSystems\Meilisearch\System\Object\AbstractClassRegistry;
+
+/**
+ * Class FacetRegistry
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class FacetRegistry extends AbstractClassRegistry
+{
+    /**
+     * Array of available parser classNames
+     *
+     * @var array
+     */
+    protected $classMap = [
+        'options' => OptionsPackage::class,
+        'hierarchy' => HierarchyPackage::class,
+        'queryGroup' => QueryGroupPackage::class,
+        'dateRange' => DateRangePackage::class,
+        'numericRange' => NumericRangePackage::class,
+    ];
+
+    /**
+     * Default parser className
+     *
+     * @var string
+     */
+    protected $defaultClass = OptionsPackage::class;
+
+    /**
+     * Get defaultParser
+     *
+     * @return string
+     */
+    public function getDefaultPackage()
+    {
+        return $this->defaultClass;
+    }
+
+    /**
+     * Set defaultParser
+     *
+     * @param string $defaultPackageClassName
+     */
+    public function setDefaultPackage($defaultPackageClassName)
+    {
+        $this->defaultClass = $defaultPackageClassName;
+    }
+
+    /**
+     * Get registered parser classNames
+     *
+     * @return array
+     */
+    public function getPackages()
+    {
+        return $this->classMap;
+    }
+
+    /**
+     * @param string $className
+     * @param string $type
+     * @throws \InvalidArgumentException
+     */
+    public function registerPackage($className, $type)
+    {
+        return $this->register($className, $type, AbstractFacetPackage::class);
+    }
+
+    /**
+     * Get package
+     *
+     * @param string $type
+     * @return AbstractFacetPackage
+     * @throws InvalidFacetPackageException
+     */
+    public function getPackage($type)
+    {
+        $instance = $this->getInstance($type);
+        if (!$instance instanceof AbstractFacetPackage) {
+            throw new InvalidFacetPackageException('Invalid class registered for ' . htmlspecialchars($type));
+        }
+        $instance->setObjectManager($this->objectManager);
+        return $instance;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/FacetUrlDecoderInterface.php

@@ -0,0 +1,45 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2012-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+/**
+ * The facet url encode is responsible to encode and decode values for EXT:meilisearch urls.
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+interface FacetUrlDecoderInterface
+{
+
+    /**
+     * Parses the query filter from GET parameters in the URL and translates it
+     * to a Lucene filter value.
+     *
+     * @param string $value the filter query from plugin
+     * @param array $configuration Facet configuration
+     * @return string Value to be used in a Lucene filter
+     */
+    public function decode($value, array $configuration = []);
+}

Classes/Domain/Search/ResultSet/Facets/InvalidFacetPackageException.php

@@ -0,0 +1,27 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017- Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+class InvalidFacetPackageException extends \Exception {}

Classes/Domain/Search/ResultSet/Facets/InvalidFacetParserException.php

@@ -0,0 +1,27 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017- Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+class InvalidFacetParserException extends \Exception {}

Classes/Domain/Search/ResultSet/Facets/InvalidQueryBuilderException.php

@@ -0,0 +1,27 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017- Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+class InvalidQueryBuilderException extends \Exception {}

Classes/Domain/Search/ResultSet/Facets/InvalidUrlDecoderException.php

@@ -0,0 +1,27 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2017- Timo Hund <timo.hund@dkd.de>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+class InvalidUrlDecoderException extends \Exception {}

Classes/Domain/Search/ResultSet/Facets/OptionBased/AbstractOptionFacetItem.php

@@ -0,0 +1,69 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+*/
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacet;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetItem;
+
+/**
+ * Base class for all facet items that are represented as option
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class AbstractOptionFacetItem extends AbstractFacetItem
+{
+    /**
+     * @var string
+     */
+    protected $value = '';
+
+    /**
+     * @param AbstractFacet $facet
+     * @param string $label
+     * @param string $value
+     * @param int $documentCount
+     * @param bool $selected
+     * @param array $metrics
+     */
+    public function __construct(AbstractFacet $facet, $label = '', $value = '', $documentCount = 0, $selected = false, $metrics = [])
+    {
+        $this->value = $value;
+        parent::__construct($facet, $label, $documentCount, $selected, $metrics);
+    }
+
+    /**
+     * @return string
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+
+    /**
+     * @return string
+     */
+    public function getUriValue()
+    {
+        return $this->getValue();
+    }
+
+    /**
+     * @return string
+     */
+    public function getCollectionKey()
+    {
+        return $this->getValue();
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/AbstractOptionsFacet.php

@@ -0,0 +1,92 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacet;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+
+/**
+ * Class AbstractOptionsFacet
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class AbstractOptionsFacet extends AbstractFacet
+{
+
+    /**
+     * @var OptionCollection
+     */
+    protected $options;
+
+    /**
+     * OptionsFacet constructor
+     *
+     * @param SearchResultSet $resultSet
+     * @param string $name
+     * @param string $field
+     * @param string $label
+     * @param array $configuration Facet configuration passed from typoscript
+     */
+    public function __construct(SearchResultSet $resultSet, $name, $field, $label = '', array $configuration = [])
+    {
+        parent::__construct($resultSet, $name, $field, $label, $configuration);
+        $this->options = new OptionCollection();
+    }
+
+    /**
+     * @return OptionCollection
+     */
+    public function getOptions()
+    {
+        return $this->options;
+    }
+
+    /**
+     * @param OptionCollection $options
+     */
+    public function setOptions($options)
+    {
+        $this->options = $options;
+    }
+
+    /**
+     * @param AbstractOptionFacetItem $option
+     */
+    public function addOption(AbstractOptionFacetItem $option)
+    {
+        $this->options->add($option);
+    }
+
+    /**
+     * The implementation of this method should return a "flatten" collection of all items.
+     *
+     * @return OptionCollection
+     */
+    public function getAllFacetItems()
+    {
+        return $this->options;
+    }
+
+    /**
+     * Get facet partial name used for rendering the facet
+     *
+     * @return string
+     */
+    public function getPartialName()
+    {
+        return !empty($this->configuration['partialName']) ? $this->configuration['partialName'] : 'Options';
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/HierarchyFacet.php

@@ -0,0 +1,130 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacet;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetItemCollection;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+
+/**
+ * Value object that represent a options facet.
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class HierarchyFacet extends AbstractFacet
+{
+    const TYPE_HIERARCHY = 'hierarchy';
+
+    /**
+     * String
+     * @var string
+     */
+    protected static $type = self::TYPE_HIERARCHY;
+
+    /**
+     * @var NodeCollection
+     */
+    protected $childNodes;
+
+    /**
+     * @var NodeCollection
+     */
+    protected $allNodes;
+
+    /**
+     * @var array
+     */
+    protected $nodesByKey = [];
+
+    /**
+     * OptionsFacet constructor
+     *
+     * @param SearchResultSet $resultSet
+     * @param string $name
+     * @param string $field
+     * @param string $label
+     * @param array $configuration Facet configuration passed from typoscript
+     */
+    public function __construct(SearchResultSet $resultSet, $name, $field, $label = '', array $configuration = [])
+    {
+        parent::__construct($resultSet, $name, $field, $label, $configuration);
+        $this->childNodes = new NodeCollection();
+        $this->allNodes = new NodeCollection();
+    }
+
+    /**
+     * @param Node $node
+     */
+    public function addChildNode(Node $node)
+    {
+        $this->childNodes->add($node);
+    }
+
+    /**
+     * @return NodeCollection
+     */
+    public function getChildNodes()
+    {
+        return $this->childNodes;
+    }
+
+    /**
+     * Creates a new node on the right position with the right parent node.
+     *
+     * @param string  $parentKey
+     * @param string $key
+     * @param string $label
+     * @param string $value
+     * @param integer $count
+     * @param boolean $selected
+     */
+    public function createNode($parentKey, $key, $label, $value, $count, $selected)
+    {
+        /** @var $parentNode Node|null */
+        $parentNode = isset($this->nodesByKey[$parentKey]) ? $this->nodesByKey[$parentKey] : null;
+        /** @var Node $node */
+        $node = $this->objectManager->get(Node::class, $this, $parentNode, $key, $label, $value, $count, $selected);
+        $this->nodesByKey[$key] = $node;
+
+        if ($parentNode === null) {
+            $this->addChildNode($node);
+        } else {
+            $parentNode->addChildNode($node);
+        }
+
+        $this->allNodes->add($node);
+    }
+
+    /**
+     * Get facet partial name used for rendering the facet
+     *
+     * @return string
+     */
+    public function getPartialName()
+    {
+        return !empty($this->configuration['partialName']) ? $this->configuration['partialName'] : 'Hierarchy';
+    }
+
+    /**
+     * The implementation of this method should return a "flatten" collection of all items.
+     *
+     * @return AbstractFacetItemCollection
+     */
+    public function getAllFacetItems()
+    {
+        return $this->allNodes;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/HierarchyFacetParser.php

@@ -0,0 +1,159 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetParser;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\SearchResultSet;
+use WapplerSystems\Meilisearch\System\Solr\ParsingUtil;
+
+/**
+ * Class HierarchyFacetParser
+ */
+class HierarchyFacetParser extends AbstractFacetParser
+{
+    /**
+     * @param SearchResultSet $resultSet
+     * @param string $facetName
+     * @param array $facetConfiguration
+     * @return HierarchyFacet|null
+     */
+    public function parse(SearchResultSet $resultSet, $facetName, array $facetConfiguration)
+    {
+        $response = $resultSet->getResponse();
+        $fieldName = $facetConfiguration['field'];
+        $label = $this->getPlainLabelOrApplyCObject($facetConfiguration);
+        $optionsFromSolrResponse = isset($response->facet_counts->facet_fields->{$fieldName}) ? ParsingUtil::getMapArrayFromFlatArray($response->facet_counts->facet_fields->{$fieldName}) : [];
+        $optionsFromRequest = $this->getActiveFacetValuesFromRequest($resultSet, $facetName);
+        $hasOptionsInResponse = !empty($optionsFromSolrResponse);
+        $hasSelectedOptionsInRequest = count($optionsFromRequest) > 0;
+        $hasNoOptionsToShow = !$hasOptionsInResponse && !$hasSelectedOptionsInRequest;
+        $hideEmpty = !$resultSet->getUsedSearchRequest()->getContextTypoScriptConfiguration()->getSearchFacetingShowEmptyFacetsByName($facetName);
+
+        if ($hasNoOptionsToShow && $hideEmpty) {
+            return null;
+        }
+
+        /** @var $facet HierarchyFacet */
+        $facet = $this->objectManager->get(HierarchyFacet::class, $resultSet, $facetName, $fieldName, $label, $facetConfiguration);
+
+        $hasActiveOptions = count($optionsFromRequest) > 0;
+        $facet->setIsUsed($hasActiveOptions);
+
+        $facet->setIsAvailable($hasOptionsInResponse);
+
+        $nodesToCreate = $this->getMergedFacetValueFromSearchRequestAndSolrResponse($optionsFromSolrResponse, $optionsFromRequest);
+
+        if ($this->facetOptionsMustBeResorted($facetConfiguration)) {
+            $nodesToCreate = $this->sortFacetOptionsInNaturalOrder($nodesToCreate);
+        }
+
+        foreach ($nodesToCreate as $value => $count) {
+            if ($this->getIsExcludedFacetValue($value, $facetConfiguration)) {
+                continue;
+            }
+            $isActive = in_array($value, $optionsFromRequest);
+            $delimiterPosition = strpos($value, '-');
+            $path = substr($value, $delimiterPosition + 1);
+            $pathArray = $this->getPathAsArray($path);
+            $key = array_pop($pathArray);
+            $parentKey = array_pop($pathArray);
+            $value = '/' . $path;
+            $label = $this->getLabelFromRenderingInstructions($key, $count, $facetName, $facetConfiguration);
+
+            $facet->createNode($parentKey, $key, $label, $value, $count, $isActive);
+        }
+
+        return $facet;
+    }
+
+    /**
+     * Sorts facet options in natural order.
+     * Options must be sorted in natural order,
+     * because lower nesting levels must be instantiated first, to serve as parents for higher nested levels.
+     * See implementation of HierarchyFacet::createNode().
+     *
+     * @param array $flatOptionsListForFacet
+     * @return void sorted list of facet options
+     */
+    protected function sortFacetOptionsInNaturalOrder(array $flatOptionsListForHierarchyFacet)
+    {
+        uksort($flatOptionsListForHierarchyFacet, "strnatcmp");
+        return $flatOptionsListForHierarchyFacet;
+    }
+
+    /**
+     * Checks if options must be resorted.
+     *
+     * Apache Solr facet.sort can be set globally or per facet.
+     * Relevant TypoScript paths:
+     * plugin.tx_meilisearch.search.faceting.sortBy causes facet.sort Apache Solr parameter
+     * plugin.tx_meilisearch.search.faceting.facets.[facetName].sortBy causes f.<fieldname>.facet.sort parameter
+     *
+     * see: https://lucene.apache.org/solr/guide/6_6/faceting.html#Faceting-Thefacet.sortParameter
+     * see: https://wiki.apache.org/solr/SimpleFacetParameters#facet.sort : "This parameter can be specified on a per field basis."
+     *
+     * @param array $facetConfiguration
+     * @return bool
+     */
+    protected function facetOptionsMustBeResorted(array $facetConfiguration)
+    {
+        if (isset($facetConfiguration['sortBy']) && $facetConfiguration['sortBy'] === 'index') {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * This method is used to get the path array from a hierarchical facet. It substitutes escaped slashes to keep them
+     * when they are used inside a facetValue.
+     *
+     * @param string $path
+     * @return array
+     */
+    protected function getPathAsArray($path)
+    {
+        $path = str_replace('\/', '@@@', $path);
+        $path = rtrim($path, "/");
+        $segments = explode('/', $path);
+        return array_map(function($item) {
+            return str_replace('@@@', '/', $item);
+        }, $segments);
+    }
+
+    /**
+     * Retrieves the active facetValue for a facet from the search request.
+     * @param SearchResultSet $resultSet
+     * @param string $facetName
+     * @return array
+     */
+    protected function getActiveFacetValuesFromRequest(SearchResultSet $resultSet, $facetName)
+    {
+        $activeFacetValues = [];
+        $values = $resultSet->getUsedSearchRequest()->getActiveFacetValuesByName($facetName);
+
+        foreach (is_array($values) ? $values : [] as $valueFromRequest) {
+            // Attach the 'depth' param again to the value
+            if (strpos($valueFromRequest, '-') === false) {
+                $valueFromRequest = HierarchyTool::substituteSlashes($valueFromRequest);
+                $valueFromRequest = trim($valueFromRequest, '/');
+                $valueFromRequest = (count(explode('/', $valueFromRequest)) - 1) . '-' . $valueFromRequest . '/';
+                $valueFromRequest = HierarchyTool::unSubstituteSlashes($valueFromRequest);
+            }
+            $activeFacetValues[] = $valueFromRequest;
+        }
+        return $activeFacetValues;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/HierarchyPackage.php

@@ -0,0 +1,37 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetPackage;
+
+/**
+ * Class HierarchyPackage
+ */
+class HierarchyPackage extends AbstractFacetPackage {
+
+    /**
+     * @return string
+     */
+    public function getParserClassName() {
+        return (string)HierarchyFacetParser::class;
+    }
+
+    /**
+     * @return string
+     */
+    public function getUrlDecoderClassName() {
+        return (string)HierarchyUrlDecoder::class;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/HierarchyTool.php

@@ -0,0 +1,41 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+*/
+
+class HierarchyTool
+{
+    /**
+     * Replaces all escaped slashes in a hierarchy path with @@@slash@@@ to afterwards
+     * only have slashes in the content that are real path separators.
+     *
+     * @param string $pathWithContentSlashes
+     * @return string
+     */
+    public static function substituteSlashes(string $pathWithContentSlashes): string
+    {
+        return  (string)str_replace('\/', '@@@slash@@@', $pathWithContentSlashes);
+    }
+
+    /**
+     * Replaces @@@slash@@@ with \/ to have the path usable for solr again.
+     *
+     * @param string $pathWithReplacedContentSlashes
+     * @return string
+     */
+    public static function unSubstituteSlashes(string $pathWithReplacedContentSlashes): string
+    {
+        return (string)str_replace('@@@slash@@@', '\/', $pathWithReplacedContentSlashes);
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/HierarchyUrlDecoder.php

@@ -0,0 +1,64 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) 2012-2015 Ingo Renner <ingo@typo3.org>
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\FacetUrlDecoderInterface;
+
+/**
+ * Filter encoder to build Solr hierarchy queries from tx_meilisearch[filter]
+ *
+ * @author Ingo Renner <ingo@typo3.org>
+ */
+class HierarchyUrlDecoder implements FacetUrlDecoderInterface
+{
+
+    /**
+     * Delimiter for hierarchies in the URL.
+     *
+     * @var string
+     */
+    const DELIMITER = '/';
+
+    /**
+     * Parses the given hierarchy filter and returns a Solr filter query.
+     *
+     * @param string $hierarchy The hierarchy filter query.
+     * @param array $configuration Facet configuration
+     * @return string Lucene query language filter to be used for querying Solr
+     */
+    public function decode($hierarchy, array $configuration = [])
+    {
+        $escapedHierarchy = HierarchyTool::substituteSlashes($hierarchy);
+
+        $escapedHierarchy = substr($escapedHierarchy, 1);
+        $escapedHierarchy = rtrim($escapedHierarchy, '/');
+        $hierarchyItems = explode(self::DELIMITER, $escapedHierarchy);
+        $filterContent = (count($hierarchyItems) - 1) . '-' . $escapedHierarchy . '/';
+
+        $filterContent = HierarchyTool::unSubstituteSlashes($filterContent);
+
+        return '"' . str_replace("\\", "\\\\", $filterContent) . '"';
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/Node.php

@@ -0,0 +1,119 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+*/
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\AbstractOptionFacetItem;
+
+/**
+ * Value object that represent an option of a options facet.
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class Node extends AbstractOptionFacetItem
+{
+
+    /**
+     * @var NodeCollection
+     */
+    protected $childNodes;
+
+    /**
+     * @var Node
+     */
+    protected $parentNode;
+
+    /**
+     * @var integer
+     */
+    protected $depth;
+
+    /**
+     * @var string
+     */
+    protected $key;
+
+    /**
+     * @param HierarchyFacet $facet
+     * @param Node $parentNode
+     * @param string $key
+     * @param string $label
+     * @param string $value
+     * @param int $documentCount
+     * @param bool $selected
+     */
+    public function __construct(HierarchyFacet $facet, $parentNode = null, $key = '', $label = '', $value = '', $documentCount = 0, $selected = false)
+    {
+        parent::__construct($facet, $label, $value, $documentCount, $selected);
+        $this->value = $value;
+        $this->childNodes = new NodeCollection();
+        $this->parentNode = $parentNode;
+        $this->key = $key;
+    }
+
+    /**
+     * @return string
+     */
+    public function getKey()
+    {
+        return $this->key;
+    }
+
+    /**
+     * @param Node $node
+     */
+    public function addChildNode(Node $node)
+    {
+        $this->childNodes->add($node);
+    }
+
+    /**
+     * @return NodeCollection
+     */
+    public function getChildNodes()
+    {
+        return $this->childNodes;
+    }
+
+    /**
+     * @return Node|null
+     */
+    public function getParentNode()
+    {
+        return $this->parentNode;
+    }
+
+    /**
+     * @return bool
+     */
+    public function getHasParentNode()
+    {
+        return $this->parentNode !== null;
+    }
+
+    /**
+     * @return bool
+     */
+    public function getHasChildNodeSelected()
+    {
+        /** @var Node $childNode */
+        foreach ($this->childNodes as $childNode) {
+            if ($childNode->getSelected()) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/Hierarchy/NodeCollection.php

@@ -0,0 +1,44 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Hierarchy;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetItemCollection;
+
+/**
+ * Collection for facet options.
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class NodeCollection extends AbstractFacetItemCollection
+{
+
+    /**
+     * @param Node $node
+     * @return NodeCollection
+     */
+    public function add($node)
+    {
+        return parent::add($node);
+    }
+
+    /**
+     * @param int $position
+     * @return Node
+     */
+    public function getByPosition($position)
+    {
+        return parent::getByPosition($position);
+    }
+}

Classes/Domain/Search/ResultSet/Facets/OptionBased/OptionCollection.php

@@ -0,0 +1,75 @@
+<?php
+namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacetItemCollection;
+use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\OptionBased\Options\Option;
+
+/**
+ * Collection for facet options.
+ *
+ * @author Frans Saris <frans@beech.it>
+ * @author Timo Hund <timo.hund@dkd.de>
+ */
+class OptionCollection extends AbstractFacetItemCollection
+{
+
+    /**
+     * Returns an array of prefixes from the option labels.
+     *
+     * Red, Blue, Green => r, g, b
+     *
+     * Can be used in combination with getByPrefix() to group facet options by prefix (e.g. alphabetical).
+     *
+     * @param int $length
+     * @return array
+     */
+    public function getLowercaseLabelPrefixes($length = 1)
+    {
+        $prefixes = $this->getLabelPrefixes($length);
+        return array_map('mb_strtolower', $prefixes);
+    }
+
+    /**
+     * @param string $filteredPrefix
+     * @return AbstractFacetItemCollection
+     */
+    public function getByLowercaseLabelPrefix($filteredPrefix)
+    {
+        return $this->getFilteredCopy(function(Option $option) use ($filteredPrefix)
+        {
+            $filteredPrefixLength = mb_strlen($filteredPrefix);
+            $currentPrefix = mb_substr(mb_strtolower($option->getLabel()), 0, $filteredPrefixLength);
+
+            return $currentPrefix === $filteredPrefix;
+        });
+    }
+
+    /**
+     * @param int $length
+     * @return array
+     */
+    protected function getLabelPrefixes($length = 1) : array
+    {
+        $prefixes = [];
+        foreach ($this->data as $option) {
+            /** @var $option Option */
+            $prefix = mb_substr($option->getLabel(), 0, $length);
+            $prefixes[$prefix] = $prefix;
+        }
+
+        return array_values($prefixes);
+    }
+}