Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\EventSubscriber;
Chris@0: 
Chris@0: use Drupal\Core\Cache\CacheableResponseInterface;
Chris@0: use Drupal\Core\Routing\AccessAwareRouterInterface;
Chris@0: use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
Chris@0: use Symfony\Component\HttpKernel\KernelEvents;
Chris@0: use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Response subscriber to bubble the route's access result's cacheability.
Chris@0:  *
Chris@0:  * During routing, access checking is performed. The corresponding access result
Chris@0:  * is stored in the Request object's attributes, just like the matching route
Chris@0:  * object is. In case of a cacheable response, the route's access result also
Chris@0:  * determined the content of the response, and therefore the cacheability of the
Chris@0:  * route's access result should also be applied to the resulting response.
Chris@0:  *
Chris@0:  * @see \Drupal\Core\Routing\AccessAwareRouterInterface::ACCESS_RESULT
Chris@0:  * @see \Drupal\Core\Routing\AccessAwareRouter::matchRequest()
Chris@0:  * @see \Drupal\Core\Routing\AccessAwareRouter::checkAccess()
Chris@0:  */
Chris@0: class RouteAccessResponseSubscriber implements EventSubscriberInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * Bubbles the route's access result' cacheability metadata.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
Chris@0:    *   The event to process.
Chris@0:    */
Chris@0:   public function onRespond(FilterResponseEvent $event) {
Chris@0:     if (!$event->isMasterRequest()) {
Chris@0:       return;
Chris@0:     }
Chris@0: 
Chris@0:     $response = $event->getResponse();
Chris@0:     if (!$response instanceof CacheableResponseInterface) {
Chris@0:       return;
Chris@0:     }
Chris@0: 
Chris@0:     $request = $event->getRequest();
Chris@0:     $access_result = $request->attributes->get(AccessAwareRouterInterface::ACCESS_RESULT);
Chris@0:     $response->addCacheableDependency($access_result);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function getSubscribedEvents() {
Chris@0:     // Priority 10, so that it runs before FinishResponseSubscriber, which will
Chris@0:     // expose the cacheability metadata in the form of headers.
Chris@0:     $events[KernelEvents::RESPONSE][] = ['onRespond', 10];
Chris@0:     return $events;
Chris@0:   }
Chris@0: 
Chris@0: }