Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\node\Access;
Chris@0: 
Chris@0: use Drupal\Core\Access\AccessResult;
Chris@18: use Drupal\Core\Entity\EntityTypeManagerInterface;
Chris@0: use Drupal\Core\Routing\Access\AccessInterface;
Chris@0: use Drupal\Core\Session\AccountInterface;
Chris@0: use Drupal\node\NodeInterface;
Chris@0: use Symfony\Component\Routing\Route;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides an access checker for node revisions.
Chris@0:  *
Chris@0:  * @ingroup node_access
Chris@0:  */
Chris@0: class NodeRevisionAccessCheck implements AccessInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The node storage.
Chris@0:    *
Chris@0:    * @var \Drupal\node\NodeStorageInterface
Chris@0:    */
Chris@0:   protected $nodeStorage;
Chris@0: 
Chris@0:   /**
Chris@0:    * The node access control handler.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Entity\EntityAccessControlHandlerInterface
Chris@0:    */
Chris@0:   protected $nodeAccess;
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 NodeRevisionAccessCheck.
Chris@0:    *
Chris@18:    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
Chris@18:    *   The entity type manager.
Chris@0:    */
Chris@18:   public function __construct(EntityTypeManagerInterface $entity_type_manager) {
Chris@18:     $this->nodeStorage = $entity_type_manager->getStorage('node');
Chris@18:     $this->nodeAccess = $entity_type_manager->getAccessControlHandler('node');
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Checks routing access for the node 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 $node_revision
Chris@0:    *   (optional) The node revision ID. If not specified, but $node is, access
Chris@0:    *   is checked for that object's revision.
Chris@0:    * @param \Drupal\node\NodeInterface $node
Chris@0:    *   (optional) A node object. Used for checking access to a node's default
Chris@0:    *   revision when $node_revision is unspecified. Ignored when $node_revision
Chris@0:    *   is specified. If neither $node_revision nor $node are specified, then
Chris@0:    *   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, $node_revision = NULL, NodeInterface $node = NULL) {
Chris@0:     if ($node_revision) {
Chris@0:       $node = $this->nodeStorage->loadRevision($node_revision);
Chris@0:     }
Chris@0:     $operation = $route->getRequirement('_access_node_revision');
Chris@0:     return AccessResult::allowedIf($node && $this->checkAccess($node, $account, $operation))->cachePerPermissions()->addCacheableDependency($node);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Checks node revision access.
Chris@0:    *
Chris@0:    * @param \Drupal\node\NodeInterface $node
Chris@0:    *   The node 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(NodeInterface $node, AccountInterface $account, $op = 'view') {
Chris@0:     $map = [
Chris@0:       'view' => 'view all revisions',
Chris@0:       'update' => 'revert all revisions',
Chris@0:       'delete' => 'delete all revisions',
Chris@0:     ];
Chris@0:     $bundle = $node->bundle();
Chris@0:     $type_map = [
Chris@0:       'view' => "view $bundle revisions",
Chris@0:       'update' => "revert $bundle revisions",
Chris@0:       'delete' => "delete $bundle revisions",
Chris@0:     ];
Chris@0: 
Chris@0:     if (!$node || !isset($map[$op]) || !isset($type_map[$op])) {
Chris@0:       // If there was no node 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 = $node->language()->getId();
Chris@0:     $cid = $node->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($map[$op]) && !$account->hasPermission($type_map[$op]) && !$account->hasPermission('administer nodes')) {
Chris@0:         $this->access[$cid] = FALSE;
Chris@0:         return FALSE;
Chris@0:       }
Chris@18:       // If the revisions checkbox is selected for the content type, display the
Chris@18:       // revisions tab.
Chris@18:       $bundle_entity_type = $node->getEntityType()->getBundleEntityType();
Chris@18:       $bundle_entity = \Drupal::entityTypeManager()->getStorage($bundle_entity_type)->load($bundle);
Chris@18:       if ($bundle_entity->shouldCreateNewRevision() && $op === 'view') {
Chris@0:         $this->access[$cid] = TRUE;
Chris@0:       }
Chris@0:       else {
Chris@18:         // There should be at least two revisions. If the vid of the given node
Chris@18:         // and the vid of the default revision differ, then we already have two
Chris@18:         // different revisions so there is no need for a separate database
Chris@18:         // check. Also, if you try to revert to or delete the default revision,
Chris@18:         // that's not good.
Chris@18:         if ($node->isDefaultRevision() && ($this->nodeStorage->countDefaultLanguageRevisions($node) == 1 || $op === 'update' || $op === 'delete')) {
Chris@18:           $this->access[$cid] = FALSE;
Chris@18:         }
Chris@18:         elseif ($account->hasPermission('administer nodes')) {
Chris@18:           $this->access[$cid] = TRUE;
Chris@18:         }
Chris@18:         else {
Chris@18:           // First check the access to the default revision and finally, if the
Chris@18:           // node passed in is not the default revision then check access to
Chris@18:           // that, too.
Chris@18:           $this->access[$cid] = $this->nodeAccess->access($this->nodeStorage->load($node->id()), $op, $account) && ($node->isDefaultRevision() || $this->nodeAccess->access($node, $op, $account));
Chris@18:         }
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $this->access[$cid];
Chris@0:   }
Chris@0: 
Chris@0: }