panopoly_media-8.x-2.x-dev/src/Form/FileDeleteForm.php

<?php

namespace Drupal\panopoly_media\Form;

use Drupal\Component\Datetime\TimeInterface;
use Drupal\Core\Entity\ContentEntityDeleteForm;
use Drupal\Core\Entity\EntityRepositoryInterface;
use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
use Drupal\file\FileUsage\FileUsageInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides a form for deleting a file.
 */
class FileDeleteForm extends ContentEntityDeleteForm {

  /**
   * The file usage service.
   *
   * @var \Drupal\file\FileUsage\FileUsageInterface
   */
  protected $fileUsage;

  /**
   * Constructs a FileDeleteForm object.
   *
   * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
   *   The entity manager.
   * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
   *   The entity type bundle service.
   * @param \Drupal\Component\Datetime\TimeInterface $time
   *   The time service.
   * @param \Drupal\file\FileUsage\FileUsageInterface $fileUsage
   *   The file usage service.
   */
  public function __construct(EntityRepositoryInterface $entity_repository, ?EntityTypeBundleInfoInterface $entity_type_bundle_info = NULL, ?TimeInterface $time = NULL, ?FileUsageInterface $fileUsage = NULL) {
    parent::__construct($entity_repository, $entity_type_bundle_info, $time);
    $this->fileUsage = $fileUsage;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('entity.repository'),
      $container->get('entity_type.bundle.info'),
      $container->get('datetime.time'),
      $container->get('file.usage')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form = parent::buildForm($form, $form_state);

    /** @var \Drupal\file\FileInterface $file */
    if ($this->fileUsage->listUsage($this->entity)) {
      $form['warning'] = [
        '#theme' => 'status_messages',
        // @todo Improve when https://www.drupal.org/node/2278383 lands.
        '#message_list' => ['warning' => [$this->t('This file has usages recorded. Deleting it may affect content that attempts to reference it.')]],
        '#status_headings' => [
          'status' => $this->t('Status message'),
          'error' => $this->t('Error message'),
          'warning' => $this->t('Warning message'),
        ],
      ];
    }

    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function getCancelUrl() {
    // Needed because there is no canonical link for file entities.
    return Url::fromRoute('<front>');
  }

}