AnonymousUserResponseSubscriber.php

Same filename in other branches
  1. 8.9.x core/lib/Drupal/Core/EventSubscriber/AnonymousUserResponseSubscriber.php
  2. 10 core/lib/Drupal/Core/EventSubscriber/AnonymousUserResponseSubscriber.php
  3. 11.x core/lib/Drupal/Core/EventSubscriber/AnonymousUserResponseSubscriber.php

Namespace

Drupal\Core\EventSubscriber

File

core/lib/Drupal/Core/EventSubscriber/AnonymousUserResponseSubscriber.php

View source
<?php

namespace Drupal\Core\EventSubscriber;

use Drupal\Core\Cache\CacheableMetadata;
use Drupal\Core\Cache\CacheableResponseInterface;
use Drupal\Core\Session\AccountInterface;
use Symfony\Component\HttpKernel\Event\ResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Response subscriber to handle finished responses for the anonymous user.
 */
class AnonymousUserResponseSubscriber implements EventSubscriberInterface {
    
    /**
     * The current user.
     *
     * @var \Drupal\Core\Session\AccountInterface
     */
    protected $currentUser;
    
    /**
     * Constructs an AnonymousUserResponseSubscriber object.
     *
     * @param \Drupal\Core\Session\AccountInterface $current_user
     *   The current user.
     */
    public function __construct(AccountInterface $current_user) {
        $this->currentUser = $current_user;
    }
    
    /**
     * Adds a cache tag if the 'user.permissions' cache context is present.
     *
     * @param \Symfony\Component\HttpKernel\Event\ResponseEvent $event
     *   The event to process.
     */
    public function onRespond(ResponseEvent $event) {
        if (!$event->isMainRequest()) {
            return;
        }
        if (!$this->currentUser
            ->isAnonymous()) {
            return;
        }
        $response = $event->getResponse();
        if (!$response instanceof CacheableResponseInterface) {
            return;
        }
        // The 'user.permissions' cache context ensures that if the permissions for
        // a role are modified, users are not served stale render cache content.
        // But, when entire responses are cached in reverse proxies, the value for
        // the cache context is never calculated, causing the stale response to not
        // be invalidated. Therefore, when varying by permissions and the current
        // user is the anonymous user, also add the cache tag for the 'anonymous'
        // role.
        if (in_array('user.permissions', $response->getCacheableMetadata()
            ->getCacheContexts())) {
            $per_permissions_response_for_anon = new CacheableMetadata();
            $per_permissions_response_for_anon->setCacheTags([
                'config:user.role.anonymous',
            ]);
            $response->addCacheableDependency($per_permissions_response_for_anon);
        }
    }
    
    /**
     * Registers the methods in this class that should be listeners.
     *
     * @return array
     *   An array of event listener definitions.
     */
    public static function getSubscribedEvents() {
        // Priority 5, so that it runs before FinishResponseSubscriber, but after
        // event subscribers that add the associated cacheability metadata (which
        // have priority 10). This one is conditional, so must run after those.
        $events[KernelEvents::RESPONSE][] = [
            'onRespond',
            5,
        ];
        return $events;
    }

}

Classes

Title Deprecated Summary
AnonymousUserResponseSubscriber Response subscriber to handle finished responses for the anonymous user.

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.