3 namespace Drupal\Core\EventSubscriber;
5 use Drupal\Core\Cache\CacheableMetadata;
6 use Drupal\Core\Cache\CacheableResponseInterface;
7 use Drupal\Core\DependencyInjection\ClassResolverInterface;
8 use Drupal\Core\Routing\RouteMatchInterface;
9 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
10 use Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent;
11 use Symfony\Component\HttpKernel\KernelEvents;
14 * View subscriber rendering main content render arrays into responses.
16 * Additional target rendering formats can be defined by adding another service
17 * that implements \Drupal\Core\Render\MainContent\MainContentRendererInterface
18 * and tagging it as a @code render.main_content_renderer @endcode, then
19 * \Drupal\Core\Render\MainContent\MainContentRenderersPass will detect it and
20 * use it when appropriate.
22 * @see \Drupal\Core\Render\MainContent\MainContentRendererInterface
23 * @see \Drupal\Core\Render\MainContentControllerPass
25 class MainContentViewSubscriber implements EventSubscriberInterface {
28 * The class resolver service.
30 * @var \Drupal\Core\Controller\ControllerResolverInterface
32 protected $classResolver;
35 * The current route match.
37 * @var \Drupal\Core\Routing\RouteMatchInterface
39 protected $routeMatch;
42 * The available main content renderer services, keyed per format.
46 protected $mainContentRenderers;
49 * URL query attribute to indicate the wrapper used to render a request.
51 * The wrapper format determines how the HTML is wrapped, for example in a
54 const WRAPPER_FORMAT = '_wrapper_format';
57 * Constructs a new MainContentViewSubscriber object.
59 * @param \Drupal\Core\DependencyInjection\ClassResolverInterface $class_resolver
60 * The class resolver service.
61 * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
62 * The current route match.
63 * @param array $main_content_renderers
64 * The available main content renderer service IDs, keyed by format.
66 public function __construct(ClassResolverInterface $class_resolver, RouteMatchInterface $route_match, array $main_content_renderers) {
67 $this->classResolver = $class_resolver;
68 $this->routeMatch = $route_match;
69 $this->mainContentRenderers = $main_content_renderers;
73 * Sets a response given a (main content) render array.
75 * @param \Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent $event
76 * The event to process.
78 public function onViewRenderArray(GetResponseForControllerResultEvent $event) {
79 $request = $event->getRequest();
80 $result = $event->getControllerResult();
82 // Render the controller result into a response if it's a render array.
83 if (is_array($result) && ($request->query->has(static::WRAPPER_FORMAT) || $request->getRequestFormat() == 'html')) {
84 $wrapper = $request->query->get(static::WRAPPER_FORMAT, 'html');
86 // Fall back to HTML if the requested wrapper envelope is not available.
87 $wrapper = isset($this->mainContentRenderers[$wrapper]) ? $wrapper : 'html';
89 $renderer = $this->classResolver->getInstanceFromDefinition($this->mainContentRenderers[$wrapper]);
90 $response = $renderer->renderResponse($result, $request, $this->routeMatch);
91 // The main content render array is rendered into a different Response
92 // object, depending on the specified wrapper format.
93 if ($response instanceof CacheableResponseInterface) {
94 $main_content_view_subscriber_cacheability = (new CacheableMetadata())->setCacheContexts(['url.query_args:' . static::WRAPPER_FORMAT]);
95 $response->addCacheableDependency($main_content_view_subscriber_cacheability);
97 $event->setResponse($response);
104 public static function getSubscribedEvents() {
105 $events[KernelEvents::VIEW][] = ['onViewRenderArray'];