--- /dev/null
+<?php
+
+namespace Drupal\entity_embed\Plugin\Filter;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Render\BubbleableMetadata;
+use Drupal\Core\Render\RenderContext;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\entity_embed\EntityEmbedBuilderInterface;
+use Drupal\entity_embed\Exception\EntityNotFoundException;
+use Drupal\entity_embed\Exception\RecursiveRenderingException;
+use Drupal\filter\FilterProcessResult;
+use Drupal\filter\Plugin\FilterBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\embed\DomHelperTrait;
+
+/**
+ * Provides a filter to display embedded entities based on data attributes.
+ *
+ * @Filter(
+ * id = "entity_embed",
+ * title = @Translation("Display embedded entities"),
+ * description = @Translation("Embeds entities using data attributes: data-entity-type, data-entity-uuid, and data-view-mode."),
+ * type = Drupal\filter\Plugin\FilterInterface::TYPE_TRANSFORM_REVERSIBLE
+ * )
+ */
+class EntityEmbedFilter extends FilterBase implements ContainerFactoryPluginInterface {
+
+ use DomHelperTrait;
+
+ /**
+ * The renderer service.
+ *
+ * @var \Drupal\Core\Render\RendererInterface
+ */
+ protected $renderer;
+
+ /**
+ * The entity type manager.
+ *
+ * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+ */
+ protected $entityTypeManager;
+
+ /**
+ * The entity embed builder service.
+ *
+ * @var \Drupal\entity_embed\EntityEmbedBuilderInterface
+ */
+ protected $builder;
+
+ /**
+ * Constructs a EntityEmbedFilter 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\EntityTypeManagerInterface $entity_type_manager
+ * The entity type manager.
+ * @param \Drupal\Core\Render\RendererInterface $renderer
+ * The renderer.
+ * @param \Drupal\entity_embed\EntityEmbedBuilderInterface $builder
+ * The entity embed builder service.
+ */
+ public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, RendererInterface $renderer, EntityEmbedBuilderInterface $builder) {
+ parent::__construct($configuration, $plugin_id, $plugin_definition);
+ $this->entityTypeManager = $entity_type_manager;
+ $this->renderer = $renderer;
+ $this->builder = $builder;
+ }
+
+ /**
+ * {@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'),
+ $container->get('entity_embed.builder')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function process($text, $langcode) {
+ $result = new FilterProcessResult($text);
+
+ if (strpos($text, 'data-entity-type') !== FALSE && (strpos($text, 'data-entity-embed-display') !== FALSE || strpos($text, 'data-view-mode') !== FALSE)) {
+ $dom = Html::load($text);
+ $xpath = new \DOMXPath($dom);
+
+ foreach ($xpath->query('//drupal-entity[@data-entity-type and (@data-entity-uuid or @data-entity-id) and (@data-entity-embed-display or @data-view-mode)]') as $node) {
+ /** @var \DOMElement $node */
+ $entity_type = $node->getAttribute('data-entity-type');
+ $entity = NULL;
+ $entity_output = '';
+
+ // data-entity-embed-settings is deprecated, make sure we convert it to
+ // data-entity-embed-display-settings.
+ if (($settings = $node->getAttribute('data-entity-embed-settings')) && !$node->hasAttribute('data-entity-embed-display-settings')) {
+ $node->setAttribute('data-entity-embed-display-settings', $settings);
+ $node->removeAttribute('data-entity-embed-settings');
+ }
+
+ try {
+ // Load the entity either by UUID (preferred) or ID.
+ $id = NULL;
+ $entity = NULL;
+ if ($id = $node->getAttribute('data-entity-uuid')) {
+ $entity = $this->entityTypeManager->getStorage($entity_type)
+ ->loadByProperties(['uuid' => $id]);
+ $entity = current($entity);
+ }
+ else {
+ $id = $node->getAttribute('data-entity-id');
+ $entity = $this->entityTypeManager->getStorage($entity_type)->load($id);
+ }
+
+ if ($entity) {
+ // Protect ourselves from recursive rendering.
+ static $depth = 0;
+ $depth++;
+ if ($depth > 20) {
+ throw new RecursiveRenderingException(sprintf('Recursive rendering detected when rendering embedded %s entity %s.', $entity_type, $entity->id()));
+ }
+
+ // If a UUID was not used, but is available, add it to the HTML.
+ if (!$node->getAttribute('data-entity-uuid') && $uuid = $entity->uuid()) {
+ $node->setAttribute('data-entity-uuid', $uuid);
+ }
+
+ $context = $this->getNodeAttributesAsArray($node);
+ $context += array('data-langcode' => $langcode);
+ $build = $this->builder->buildEntityEmbed($entity, $context);
+ // We need to render the embedded entity:
+ // - without replacing placeholders, so that the placeholders are
+ // only replaced at the last possible moment. Hence we cannot use
+ // either renderPlain() or renderRoot(), so we must use render().
+ // - without bubbling beyond this filter, because filters must
+ // ensure that the bubbleable metadata for the changes they make
+ // when filtering text makes it onto the FilterProcessResult
+ // object that they return ($result). To prevent that bubbling, we
+ // must wrap the call to render() in a render context.
+ $entity_output = $this->renderer->executeInRenderContext(new RenderContext(), function () use (&$build) {
+ return $this->renderer->render($build);
+ });
+ $result = $result->merge(BubbleableMetadata::createFromRenderArray($build));
+
+ $depth--;
+ }
+ else {
+ throw new EntityNotFoundException(sprintf('Unable to load embedded %s entity %s.', $entity_type, $id));
+ }
+ }
+ catch (\Exception $e) {
+ watchdog_exception('entity_embed', $e);
+ }
+
+ $this->replaceNodeContent($node, $entity_output);
+ }
+
+ $result->setProcessedText(Html::serialize($dom));
+ }
+
+ return $result;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function tips($long = FALSE) {
+ if ($long) {
+ return $this->t('
+ <p>You can embed entities. Additional properties can be added to the embed tag like data-caption and data-align if supported. Example:</p>
+ <code><drupal-entity data-entity-type="node" data-entity-uuid="07bf3a2e-1941-4a44-9b02-2d1d7a41ec0e" data-view-mode="teaser" /></code>');
+ }
+ else {
+ return $this->t('You can embed entities.');
+ }
+ }
+
+}