How to get File entity in media_presave hook?

Question

I want to get the file entity out of an media image bundle to the get the filename to check if the image is cmyk or not.

/**
 * Implements hook_ENTITY_TYPE_presave().
 */
function hook_media_presave(MediaInterface $entity) {
  if ($entity->bundle() == 'image') {
    $field_definitions = $entity->getFieldDefinitions();
    foreach ($field_definitions as $field_definition) {
      if ($field_definition->getType() 'image') {
        // get File entity here.
      }
    }
  }
}

How do I do this?

Answer 1

I've found a solution.

/**
 * Implements hook_ENTITY_TYPE_presave().
 */
function hook_media_presave(MediaInterface $entity) {
  if ($entity->bundle() == 'image') {
    $field_definitions = $entity->getFieldDefinitions();
    foreach ($field_definitions as $field_definition) {
      if ($field_definition->getType() == 'image') {
        /** @var FieldItemListInterface $field_value */
        $field_values = $entity->get($field_definition->getName())->getValue();
        if (is_array($field_values)) {
          foreach ($field_values as $field_value) {
            if ($field_value['target_id']) {
              /** @var File $file */
              $file = File::load($field_value['target_id']);
              $image = getimagesize($file->getFileUri());
              // If the image has channels '4' it is cmyk.
              if ($image['channels'] == '4') {
                $imagick = new Imagick($file->getFileUri());
                $imagick->setImageColorspace(Imagick::COLORSPACE_RGB);
                $imagick->writeImage($image);
                $imagick->destroy();
              }
            }
          }
        }
      }
    }
  }
}

Answer 2

To set the image alt text as name.

use Drupal\media\MediaInterface;


/**
 * Implements hook_ENTITY_TYPE_presave().
 */
function MODULE_NAME_media_presave(MediaInterface $entity) {
  if ($entity->bundle() == 'image' && $entity->hasField('image') && !$entity->get('image')->isEmpty()) {
    $image = $entity->get("image")->getValue();
    if (empty($image[0]['alt'])) {
      $image[0]['alt'] = $entity->get('name')->value;
      $entity->set('image', $image);
    }
  }
}