Converts custom media tokens into responsive images.

FilterImageToken.php

<?php

namespace Drupal\chromatic_image\Plugin\Filter;

use Symfony\Component\DependencyInjection\ContainerInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Drupal\Core\Render\RendererInterface;
use Drupal\filter\FilterProcessResult;
use Drupal\filter\Plugin\FilterBase;

/**
 * Provides a filter for rendering custom media tokens.
 *
 * @Filter(
 *   id = "filter_media_image_token",
 *   title = @Translation("Media Image Tokens"),
 *   description = @Translation("Renders media image tokens."),
 *   type = Drupal\filter\Plugin\FilterInterface::TYPE_TRANSFORM_IRREVERSIBLE,
 * )
 */
class FilterImageToken extends FilterBase implements ContainerFactoryPluginInterface {

  /**
   * The default responsive image style.
   */
  const DEFAULT_RESPONSIVE_STYLE = 'content_image';

  /**
   * The regex used to find the media tokens.
   */
  const TOKEN_REGEX = '/\[media:(\d+):?([a-z|_]*)\S*?\]/';

  /**
   * The entity query service.
   *
   * @var \Drupal\Core\Entity\Query\QueryFactory
   */
  protected $entityQuery;

  /**
   * The entity type manager service.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityManager;

  /**
   * The renderer service.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;

  /**
   * Constructs a token filter plugin.
   *
   * {@inheritdoc}
   */
  public function __construct(
    array $configuration,
    $plugin_id,
    $plugin_definition,
    EntityTypeManagerInterface $entityManager,
    RendererInterface $renderer) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->entityManager = $entityManager;
    $this->renderer = $renderer;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('entity_type.manager'),
      $container->get('renderer')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function process($text, $langcode) {
    $text = preg_replace_callback(
      self::TOKEN_REGEX,
      function ($matches) {
        $mediaEntity = $this->entityManager->getStorage('media')->load($matches[1]);
        if (!$mediaEntity) {
          return NULL;
        }
        $caption = $mediaEntity->field_media_image_caption->getValue();
        $image = [
          '#theme' => 'chromatic_body_image',
          '#image' => [
            '#theme' => 'responsive_image',
            '#responsive_image_style_id' => $this->determineResponsiveStyleId($matches[2]),
            '#uri' => $mediaEntity->field_media_image->entity->getFileUri(),
            '#attributes' => [
              'alt' => $mediaEntity->field_media_image->alt,
            ],
          ],
          '#caption' => !empty($caption[0]) ? check_markup($caption[0]['value'], $caption[0]['format']) : '',
          '#full_width' => (strpos($matches[0], 'full') !== FALSE),
        ];
        return $this->renderer->render($image);
      },
      $text
    );
    $result = new FilterProcessResult($text);
    return $result;
  }

  /**
   * {@inheritdoc}
   */
  public function tips($long = FALSE) {
    $build = [];
    $build[] = [
      '#markup' => $this->t('Create media image tokens using the format <code>[media:mid:responsive_style:full]</code>, the <code>content_image</code> style will be used by default. For full width images, include <code>full</code> as an optional last token segment.'),
    ];
    return $this->renderer->render($build);
  }

  /**
   * Determines the responsive image style that should be used.
   *
   * @param string $tokenImageStyle
   *   The style passed in through the token.
   *
   * @return string
   *   The verified responsive image style name.
   */
  private function determineResponsiveStyleId($tokenImageStyle) {
    $responseImageStyleStorage = $this->entityManager->getStorage('responsive_image_style');
    if (!empty($tokenImageStyle) && $responseImageStyleStorage->load($tokenImageStyle)) {
      return $tokenImageStyle;
    }
    return self::DEFAULT_RESPONSIVE_STYLE;
  }

}