Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\media\Access;
Chris@0: 
Chris@0: use Drupal\Core\Access\AccessResult;
Chris@0: use Drupal\Core\Entity\EntityTypeManagerInterface;
Chris@0: use Drupal\Core\Routing\Access\AccessInterface;
Chris@0: use Drupal\Core\Session\AccountInterface;
Chris@0: use Drupal\media\MediaInterface;
Chris@0: use Symfony\Component\Routing\Route;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides an access checker for media item revisions.
Chris@0:  *
Chris@0:  * @ingroup media_access
Chris@0:  */
Chris@0: class MediaRevisionAccessCheck implements AccessInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The media storage.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Entity\ContentEntityStorageInterface
Chris@0:    */
Chris@0:   protected $mediaStorage;
Chris@0: 
Chris@0:   /**
Chris@0:    * The media access control handler.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Entity\EntityAccessControlHandlerInterface
Chris@0:    */
Chris@0:   protected $mediaAccess;
Chris@0: 
Chris@0:   /**
Chris@0:    * A static cache of access checks.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $access = [];
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new MediaRevisionAccessCheck.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
Chris@0:    *   The entity type manager.
Chris@0:    */
Chris@0:   public function __construct(EntityTypeManagerInterface $entity_type_manager) {
Chris@0:     $this->mediaStorage = $entity_type_manager->getStorage('media');
Chris@0:     $this->mediaAccess = $entity_type_manager->getAccessControlHandler('media');
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Checks routing access for the media item revision.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\Routing\Route $route
Chris@0:    *   The route to check against.
Chris@0:    * @param \Drupal\Core\Session\AccountInterface $account
Chris@0:    *   The currently logged in account.
Chris@0:    * @param int $media_revision
Chris@0:    *   (optional) The media item revision ID. If not specified, but $media is,
Chris@0:    *   access is checked for that object's revision.
Chris@0:    * @param \Drupal\media\MediaInterface $media
Chris@0:    *   (optional) A media item. Used for checking access to a media items
Chris@0:    *   default revision when $media_revision is unspecified. Ignored when
Chris@0:    *   $media_revision is specified. If neither $media_revision nor $media are
Chris@0:    *   specified, then access is denied.
Chris@0:    *
Chris@0:    * @return \Drupal\Core\Access\AccessResultInterface
Chris@0:    *   The access result.
Chris@0:    */
Chris@0:   public function access(Route $route, AccountInterface $account, $media_revision = NULL, MediaInterface $media = NULL) {
Chris@0:     if ($media_revision) {
Chris@0:       $media = $this->mediaStorage->loadRevision($media_revision);
Chris@0:     }
Chris@0:     $operation = $route->getRequirement('_access_media_revision');
Chris@0:     return AccessResult::allowedIf($media && $this->checkAccess($media, $account, $operation))->cachePerPermissions()->addCacheableDependency($media);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Checks media item revision access.
Chris@0:    *
Chris@0:    * @param \Drupal\media\MediaInterface $media
Chris@0:    *   The media item to check.
Chris@0:    * @param \Drupal\Core\Session\AccountInterface $account
Chris@0:    *   A user object representing the user for whom the operation is to be
Chris@0:    *   performed.
Chris@0:    * @param string $op
Chris@0:    *   (optional) The specific operation being checked. Defaults to 'view'.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if the operation may be performed, FALSE otherwise.
Chris@0:    */
Chris@0:   public function checkAccess(MediaInterface $media, AccountInterface $account, $op = 'view') {
Chris@0:     if (!$media || $op !== 'view') {
Chris@0:       // If there was no media to check against, or the $op was not one of the
Chris@0:       // supported ones, we return access denied.
Chris@0:       return FALSE;
Chris@0:     }
Chris@0: 
Chris@0:     // Statically cache access by revision ID, language code, user account ID,
Chris@0:     // and operation.
Chris@0:     $langcode = $media->language()->getId();
Chris@0:     $cid = $media->getRevisionId() . ':' . $langcode . ':' . $account->id() . ':' . $op;
Chris@0: 
Chris@0:     if (!isset($this->access[$cid])) {
Chris@0:       // Perform basic permission checks first.
Chris@0:       if (!$account->hasPermission('view all media revisions') && !$account->hasPermission('administer media')) {
Chris@0:         $this->access[$cid] = FALSE;
Chris@0:         return FALSE;
Chris@0:       }
Chris@0: 
Chris@0:       // There should be at least two revisions. If the revision ID of the
Chris@0:       // given media item and the revision ID of the default revision differ,
Chris@0:       // then we already have two different revisions so there is no need for a
Chris@0:       // separate database check.
Chris@0:       if ($media->isDefaultRevision() && ($this->countDefaultLanguageRevisions($media) == 1)) {
Chris@0:         $this->access[$cid] = FALSE;
Chris@0:       }
Chris@0:       elseif ($account->hasPermission('administer media')) {
Chris@0:         $this->access[$cid] = TRUE;
Chris@0:       }
Chris@0:       else {
Chris@0:         // First check the access to the default revision and finally, if the
Chris@0:         // media passed in is not the default revision then access to that, too.
Chris@0:         $this->access[$cid] = $this->mediaAccess->access($this->mediaStorage->load($media->id()), $op, $account) && ($media->isDefaultRevision() || $this->mediaAccess->access($media, $op, $account));
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $this->access[$cid];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Counts the number of revisions in the default language.
Chris@0:    *
Chris@0:    * @param \Drupal\media\MediaInterface $media
Chris@0:    *   The media item for which to to count the revisions.
Chris@0:    *
Chris@0:    * @return int
Chris@0:    *   The number of revisions in the default language.
Chris@0:    */
Chris@0:   protected function countDefaultLanguageRevisions(MediaInterface $media) {
Chris@0:     $entity_type = $media->getEntityType();
Chris@0:     $count = $this->mediaStorage->getQuery()
Chris@0:       ->allRevisions()
Chris@0:       ->condition($entity_type->getKey('id'), $media->id())
Chris@0:       ->condition($entity_type->getKey('default_langcode'), 1)
Chris@0:       ->count()
Chris@0:       ->execute();
Chris@0:     return $count;
Chris@0:   }
Chris@0: 
Chris@0: }