93 lines
2.9 KiB
PHP
93 lines
2.9 KiB
PHP
<?php
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declare(strict_types=1);
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/*
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* This file is part of the TYPO3 CMS project.
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*
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* It is free software; you can redistribute it and/or modify it under
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* the terms of the GNU General Public License, either version 2
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* of the License, or any later version.
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*
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* For the full copyright and license information, please read the
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* LICENSE.txt file that was distributed with this source code.
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*
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* The TYPO3 project - inspiring people to share!
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*/
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namespace TYPO3\CMS\Core\Html\Srcset;
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/**
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* Generates a HTML srcset attribute for responsive images
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*/
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final class SrcsetAttribute
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{
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/** @var SrcsetCandidate[] */
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private array $candidates = [];
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private string $candidateType;
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/**
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* @param string[] $descriptors Array of srcset width (like "300w, 500w") or density (like "1x, 2x")
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* descriptors.
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* @param int|null $referenceWidth Needs to be provided if $descriptors contains density descriptors
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* (like "2x") to be able to resolve the relative image dimensions.
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* The absolute $referenceWidth will be used as "1x" width.
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*/
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public static function createFromDescriptors(array $descriptors, ?int $referenceWidth = null): SrcsetAttribute
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{
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$generator = new SrcsetAttribute();
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foreach ($descriptors as $descriptor) {
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$generator->addCandidate(SrcsetCandidate::createFromDescriptor((string)$descriptor, $referenceWidth));
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}
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return $generator;
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}
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public function addCandidate(SrcsetCandidate $candidate): static
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{
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if (!$this->isValidCandidate($candidate)) {
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throw new \InvalidArgumentException(sprintf(
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'Invalid mix of w and x descriptors in srcset: %s, ..., %s',
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$this->candidates[0]->generateSrcset(),
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$candidate->generateSrcset()
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), 1697745459);
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}
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$this->candidates[] = $candidate;
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return $this;
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}
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/**
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* @return SrcsetCandidate[]
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*/
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public function getCandidates(): array
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{
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return $this->candidates;
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}
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public function generateSrcset(): string
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{
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$uniqueSrcset = [];
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foreach ($this->candidates as $candidate) {
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$uniqueSrcset[$candidate->getDescriptor()] = $candidate->generateSrcset();
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}
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return implode(', ', $uniqueSrcset);
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}
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public function __toString()
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{
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return $this->generateSrcset();
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}
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private function isValidCandidate(SrcsetCandidate $candidate): bool
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{
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if (!isset($this->candidateType)) {
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$this->candidateType = ($candidate instanceof DensitySrcsetCandidate)
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? DensitySrcsetCandidate::class
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: WidthSrcsetCandidate::class;
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return true;
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}
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return $candidate instanceof $this->candidateType;
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}
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}
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