Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\EventSubscriber;
Chris@0: 
Chris@0: use Drupal\Core\Cache\Cache;
Chris@18: use Drupal\Core\Database\ReplicaKillSwitch;
Chris@0: use Drupal\Core\Lock\LockBackendInterface;
Chris@0: use Drupal\Core\Menu\MenuLinkManagerInterface;
Chris@0: use Drupal\Core\Routing\RoutingEvents;
Chris@0: use Symfony\Component\EventDispatcher\Event;
Chris@18: use Drupal\Core\Database\Connection;
Chris@0: use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Rebuilds the default menu links and runs menu-specific code if necessary.
Chris@0:  */
Chris@0: class MenuRouterRebuildSubscriber implements EventSubscriberInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * @var \Drupal\Core\Lock\LockBackendInterface
Chris@0:    */
Chris@0:   protected $lock;
Chris@0: 
Chris@0:   /**
Chris@0:    * The menu link plugin manager.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Menu\MenuLinkManagerInterface
Chris@0:    */
Chris@0:   protected $menuLinkManager;
Chris@0: 
Chris@0:   /**
Chris@18:    * The replica kill switch.
Chris@18:    *
Chris@18:    * @var \Drupal\Core\Database\ReplicaKillSwitch
Chris@18:    */
Chris@18:   protected $replicaKillSwitch;
Chris@18: 
Chris@18:   /**
Chris@18:    * The database connection.
Chris@18:    *
Chris@18:    * @var \Drupal\Core\Database\Connection
Chris@18:    */
Chris@18:   protected $connection;
Chris@18: 
Chris@18:   /**
Chris@0:    * Constructs the MenuRouterRebuildSubscriber object.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Lock\LockBackendInterface $lock
Chris@0:    *   The lock backend.
Chris@0:    * @param \Drupal\Core\Menu\MenuLinkManagerInterface $menu_link_manager
Chris@0:    *   The menu link plugin manager.
Chris@18:    * @param \Drupal\Core\Database\Connection $connection
Chris@18:    *   The database connection.
Chris@18:    * @param \Drupal\Core\Database\ReplicaKillSwitch $replica_kill_switch
Chris@18:    *   The replica kill switch.
Chris@0:    */
Chris@18:   public function __construct(LockBackendInterface $lock, MenuLinkManagerInterface $menu_link_manager, Connection $connection, ReplicaKillSwitch $replica_kill_switch) {
Chris@0:     $this->lock = $lock;
Chris@0:     $this->menuLinkManager = $menu_link_manager;
Chris@18:     $this->connection = $connection;
Chris@18:     $this->replicaKillSwitch = $replica_kill_switch;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Rebuilds the menu links and deletes the local_task cache tag.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\EventDispatcher\Event $event
Chris@0:    *   The event object.
Chris@0:    */
Chris@0:   public function onRouterRebuild(Event $event) {
Chris@0:     $this->menuLinksRebuild();
Chris@0:     Cache::invalidateTags(['local_task']);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Perform menu-specific rebuilding.
Chris@0:    */
Chris@0:   protected function menuLinksRebuild() {
Chris@0:     if ($this->lock->acquire(__FUNCTION__)) {
Chris@18:       $transaction = $this->connection->startTransaction();
Chris@0:       try {
Chris@0:         // Ensure the menu links are up to date.
Chris@0:         $this->menuLinkManager->rebuild();
Chris@0:         // Ignore any database replicas temporarily.
Chris@18:         $this->replicaKillSwitch->trigger();
Chris@0:       }
Chris@0:       catch (\Exception $e) {
Chris@0:         $transaction->rollBack();
Chris@0:         watchdog_exception('menu', $e);
Chris@0:       }
Chris@0: 
Chris@0:       $this->lock->release(__FUNCTION__);
Chris@0:     }
Chris@0:     else {
Chris@0:       // Wait for another request that is already doing this work.
Chris@0:       // We choose to block here since otherwise the router item may not
Chris@0:       // be available during routing resulting in a 404.
Chris@0:       $this->lock->wait(__FUNCTION__);
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function getSubscribedEvents() {
Chris@0:     // Run after CachedRouteRebuildSubscriber.
Chris@0:     $events[RoutingEvents::FINISHED][] = ['onRouterRebuild', 100];
Chris@0:     return $events;
Chris@0:   }
Chris@0: 
Chris@0: }