class EditorFileReference

class EditorFileReference extends FilterBase implements ContainerFactoryPluginInterface {
    use DeprecatedServicePropertyTrait;
    
    /**
     * {@inheritdoc}
     */
    protected $deprecatedProperties = [
        'entityManager' => 'entity.manager',
    ];
    
    /**
     * The entity repository.
     *
     * @var \Drupal\Core\Entity\EntityRepositoryInterface
     */
    protected $entityRepository;
    
    /**
     * Constructs a \Drupal\editor\Plugin\Filter\EditorFileReference object.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin_id for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
     *   The entity repository.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityRepositoryInterface $entity_repository) {
        $this->entityRepository = $entity_repository;
        parent::__construct($configuration, $plugin_id, $plugin_definition);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('entity.repository'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function process($text, $langcode) {
        $result = new FilterProcessResult($text);
        if (stristr($text, 'data-entity-type="file"') !== FALSE) {
            $dom = Html::load($text);
            $xpath = new \DOMXPath($dom);
            $processed_uuids = [];
            foreach ($xpath->query('//*[@data-entity-type="file" and @data-entity-uuid]') as $node) {
                $uuid = $node->getAttribute('data-entity-uuid');
                // If there is a 'src' attribute, set it to the file entity's current
                // URL. This ensures the URL works even after the file location changes.
                if ($node->hasAttribute('src')) {
                    $file = $this->entityRepository
                        ->loadEntityByUuid('file', $uuid);
                    if ($file instanceof FileInterface) {
                        $node->setAttribute('src', $file->createFileUrl());
                    }
                }
                // Only process the first occurrence of each file UUID.
                if (!isset($processed_uuids[$uuid])) {
                    $processed_uuids[$uuid] = TRUE;
                    $file = $this->entityRepository
                        ->loadEntityByUuid('file', $uuid);
                    if ($file instanceof FileInterface) {
                        $result->addCacheTags($file->getCacheTags());
                    }
                }
            }
            $result->setProcessedText(Html::serialize($dom));
        }
        return $result;
    }

}