class ClientErrorResponseSubscriber in Drupal 8

Response subscriber to set the '4xx-response' cache tag on 4xx responses.

Hierarchy

• class \Drupal\Core\EventSubscriber\ClientErrorResponseSubscriber implements \Symfony\Component\EventDispatcher\EventSubscriberInterface

1 string reference to 'ClientErrorResponseSubscriber'

core.services.yml in core/core.services.yml

core/core.services.yml

1 service uses ClientErrorResponseSubscriber

client_error_response_subscriber in core/core.services.yml

Drupal\Core\EventSubscriber\ClientErrorResponseSubscriber

File

core/lib/Drupal/Core/EventSubscriber/ClientErrorResponseSubscriber.php, line 14

Namespace

Drupal\Core\EventSubscriber

class ClientErrorResponseSubscriber implements EventSubscriberInterface {

  /**
   * Sets the '4xx-response' cache tag on 4xx responses.
   *
   * @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
   *   The event to process.
   */
  public function onRespond(FilterResponseEvent $event) {
    if (!$event
      ->isMasterRequest()) {
      return;
    }
    $response = $event
      ->getResponse();
    if (!$response instanceof CacheableResponseInterface) {
      return;
    }
    if ($response
      ->isClientError()) {
      $http_4xx_response_cacheability = new CacheableMetadata();
      $http_4xx_response_cacheability
        ->setCacheTags([
        '4xx-response',
      ]);
      $response
        ->addCacheableDependency($http_4xx_response_cacheability);
    }
  }

  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() {

    // Priority 10, so that it runs before FinishResponseSubscriber, which will
    // expose the cacheability metadata in the form of headers.
    $events[KernelEvents::RESPONSE][] = [
      'onRespond',
      10,
    ];
    return $events;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
ClientErrorResponseSubscriber::getSubscribedEvents	public static	function	Returns an array of event names this subscriber wants to listen to.
ClientErrorResponseSubscriber::onRespond	public	function	Sets the '4xx-response' cache tag on 4xx responses.