function Media::prepareSave

Sets the media entity's field values from the source's metadata.

Fetching the metadata could be slow (e.g., if requesting it from a remote API), so this is called by \Drupal\media\MediaStorage::save() prior to it beginning the database transaction, whereas static::preSave() executes after the transaction has already started.

@internal Expose this as an API in https://www.drupal.org/project/drupal/issues/2992426.

File

core/modules/media/src/Entity/Media.php, line 429

Class

Media

Defines the media entity class.

Namespace

Code

public function prepareSave() {
  // @todo If the source plugin talks to a remote API (e.g. oEmbed), this code
  // might be performing a fair number of HTTP requests. This is dangerously
  // brittle and should probably be handled by a queue, to avoid doing HTTP
  // operations during entity save. See
  // https://www.drupal.org/project/drupal/issues/2976875 for more.
  // In order for metadata to be mapped correctly, the original entity must be
  // set. However, that is only set once parent::save() is called, so work
  // around that by setting it here.
  if (!$this->getOriginal() && $id = $this->id()) {
    $this->setOriginal($this->entityTypeManager()
      ->getStorage('media')
      ->loadUnchanged($id));
  }
  $media_source = $this->getSource();
  foreach ($this->translations as $langcode => $data) {
    if ($this->hasTranslation($langcode)) {
      $translation = $this->getTranslation($langcode);
      // Try to set fields provided by the media source and mapped in
      // media type config.
      $original = $this->getOriginal();
      foreach ($translation->bundle->entity
        ->getFieldMap() as $metadata_attribute_name => $entity_field_name) {
        if (!$translation->hasField($entity_field_name)) {
          continue;
        }
        $set_metadata = FALSE;
        // Only save value in the entity if the field is empty, or if the
        // source field changed from one non-empty value to another non-empty
        // value.
        // 1st scenario: field is empty, safely store metadata there.
        if ($translation->get($entity_field_name)
          ->isEmpty()) {
          $set_metadata = TRUE;
        }
        else {
          // 2nd scenario: field is not empty, but the source field has
          // changed between two non-empty values.
          $original_source_field_empty = $original instanceof MediaInterface && $media_source->getSourceFieldValue($original) === NULL;
          $new_source_field_empty = $media_source->getSourceFieldValue($translation) === NULL;
          if (!$original_source_field_empty && !$new_source_field_empty && $translation->hasSourceFieldChanged()) {
            $set_metadata = TRUE;
          }
        }
        if ($set_metadata) {
          $translation->set($entity_field_name, $media_source->getMetadata($translation, $metadata_attribute_name));
        }
      }
      // Try to set a default name for this media item if no name is provided.
      if ($translation->get('name')
        ->isEmpty()) {
        $translation->setName($translation->getName());
      }
      // Set thumbnail.
      if ($translation->shouldUpdateThumbnail($this->isNew())) {
        $translation->updateThumbnail();
      }
    }
  }
}