improvements-2.x-dev/src/Plugin/Filter/ImageStyleFilter.php

<?php

namespace Drupal\improvements\Plugin\Filter;

use Drupal\Component\Utility\Html;
use Drupal\Core\StreamWrapper\PublicStream;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\filter\Attribute\Filter;
use Drupal\filter\FilterProcessResult;
use Drupal\filter\Plugin\FilterBase;
use Drupal\filter\Plugin\FilterInterface;
use Drupal\image\Entity\ImageStyle;

/**
 * @TODO Add tests
 */
#[Filter(
  id: 'image_style_filter',
  title: new TranslatableMarkup('Image style'),
  type: FilterInterface::TYPE_TRANSFORM_REVERSIBLE,
  description: new TranslatableMarkup('Apply image style to images with data-image-style attribute.'),
  weight: 20,
)]
class ImageStyleFilter extends FilterBase {

  /**
   * {@inheritDoc}
   */
  public function process($text, $langcode): FilterProcessResult {
    $result = new FilterProcessResult($text);

    if (stripos($text, 'data-image-style=') !== FALSE) {
      $text_dom = Html::load($text);
      $text_xpath = new \DOMXPath($text_dom);
      $images_nodes = $text_xpath->query('//img[@data-image-style]');
      $file_url_generator = \Drupal::service('file_url_generator');

      /** @var \DOMElement $image_node */
      foreach ($images_nodes as $image_node) {
        $image_src = $image_node->getAttribute('src');

        if ($image_uri = $this->convertPathToUri($image_src)) {
          $image_style_name = $image_node->getAttribute('data-image-style');
          $image_style = ImageStyle::load($image_style_name); /** @var ImageStyle $image_style */

          if ($image_style && $image_style->supportsUri($image_uri)) {
            $image_new_src = $image_style->buildUrl($image_uri);
            $image_new_src = $file_url_generator->transformRelative($image_new_src);
            $image_node->setAttribute('src', $image_new_src);
          }
        }
      }

      $result->setProcessedText(Html::serialize($text_dom));
    }

    return $result;
  }

  /**
   * Convert path "/sites/default/files/example.jpg" to uri "public://example.jpg".
   */
  protected function convertPathToUri(string $path): ?string {
    $public_path = base_path() . PublicStream::basePath();

    if (str_starts_with($path, $public_path . '/')) {
      return 'public://' . mb_substr($path, mb_strlen($public_path) + 1);
    }

    return NULL;
  }

}