annotate core/lib/Drupal/Core/EventSubscriber/AnonymousUserResponseSubscriber.php @ 19:fa3358dc1485 tip

Add ndrum files
author Chris Cannam
date Wed, 28 Aug 2019 13:14:47 +0100
parents 4c8ae668cc8c
children
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Chris@0 1 <?php
Chris@0 2
Chris@0 3 namespace Drupal\Core\EventSubscriber;
Chris@0 4
Chris@0 5 use Drupal\Core\Cache\CacheableMetadata;
Chris@0 6 use Drupal\Core\Cache\CacheableResponseInterface;
Chris@0 7 use Drupal\Core\Session\AccountInterface;
Chris@0 8 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
Chris@0 9 use Symfony\Component\HttpKernel\KernelEvents;
Chris@0 10 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0 11
Chris@0 12 /**
Chris@0 13 * Response subscriber to handle finished responses for the anonymous user.
Chris@0 14 */
Chris@0 15 class AnonymousUserResponseSubscriber implements EventSubscriberInterface {
Chris@0 16
Chris@0 17 /**
Chris@0 18 * The current user.
Chris@0 19 *
Chris@0 20 * @var \Drupal\Core\Session\AccountInterface
Chris@0 21 */
Chris@0 22 protected $currentUser;
Chris@0 23
Chris@0 24 /**
Chris@0 25 * Constructs an AnonymousUserResponseSubscriber object.
Chris@0 26 *
Chris@0 27 * @param \Drupal\Core\Session\AccountInterface $current_user
Chris@0 28 * The current user.
Chris@0 29 */
Chris@0 30 public function __construct(AccountInterface $current_user) {
Chris@0 31 $this->currentUser = $current_user;
Chris@0 32 }
Chris@0 33
Chris@0 34 /**
Chris@0 35 * Adds a cache tag if the 'user.permissions' cache context is present.
Chris@0 36 *
Chris@0 37 * @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
Chris@0 38 * The event to process.
Chris@0 39 */
Chris@0 40 public function onRespond(FilterResponseEvent $event) {
Chris@0 41 if (!$event->isMasterRequest()) {
Chris@0 42 return;
Chris@0 43 }
Chris@0 44
Chris@0 45 if (!$this->currentUser->isAnonymous()) {
Chris@0 46 return;
Chris@0 47 }
Chris@0 48
Chris@0 49 $response = $event->getResponse();
Chris@0 50 if (!$response instanceof CacheableResponseInterface) {
Chris@0 51 return;
Chris@0 52 }
Chris@0 53
Chris@0 54 // The 'user.permissions' cache context ensures that if the permissions for
Chris@0 55 // a role are modified, users are not served stale render cache content.
Chris@0 56 // But, when entire responses are cached in reverse proxies, the value for
Chris@0 57 // the cache context is never calculated, causing the stale response to not
Chris@0 58 // be invalidated. Therefore, when varying by permissions and the current
Chris@0 59 // user is the anonymous user, also add the cache tag for the 'anonymous'
Chris@0 60 // role.
Chris@0 61 if (in_array('user.permissions', $response->getCacheableMetadata()->getCacheContexts())) {
Chris@0 62 $per_permissions_response_for_anon = new CacheableMetadata();
Chris@0 63 $per_permissions_response_for_anon->setCacheTags(['config:user.role.anonymous']);
Chris@0 64 $response->addCacheableDependency($per_permissions_response_for_anon);
Chris@0 65 }
Chris@0 66 }
Chris@0 67
Chris@0 68 /**
Chris@0 69 * Registers the methods in this class that should be listeners.
Chris@0 70 *
Chris@0 71 * @return array
Chris@0 72 * An array of event listener definitions.
Chris@0 73 */
Chris@0 74 public static function getSubscribedEvents() {
Chris@0 75 // Priority 5, so that it runs before FinishResponseSubscriber, but after
Chris@0 76 // event subscribers that add the associated cacheability metadata (which
Chris@0 77 // have priority 10). This one is conditional, so must run after those.
Chris@0 78 $events[KernelEvents::RESPONSE][] = ['onRespond', 5];
Chris@0 79 return $events;
Chris@0 80 }
Chris@0 81
Chris@0 82 }