Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\EventSubscriber;
Chris@0: 
Chris@0: use Drupal\Core\Cache\CacheableMetadata;
Chris@0: use Drupal\Core\Cache\CacheableResponseInterface;
Chris@0: use Drupal\Core\DependencyInjection\ClassResolverInterface;
Chris@0: use Drupal\Core\Routing\RouteMatchInterface;
Chris@0: use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0: use Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent;
Chris@0: use Symfony\Component\HttpKernel\KernelEvents;
Chris@0: 
Chris@0: /**
Chris@0:  * View subscriber rendering main content render arrays into responses.
Chris@0:  *
Chris@0:  * Additional target rendering formats can be defined by adding another service
Chris@0:  * that implements \Drupal\Core\Render\MainContent\MainContentRendererInterface
Chris@0:  * and tagging it as a @code render.main_content_renderer @endcode, then
Chris@0:  * \Drupal\Core\Render\MainContent\MainContentRenderersPass will detect it and
Chris@0:  * use it when appropriate.
Chris@0:  *
Chris@0:  * @see \Drupal\Core\Render\MainContent\MainContentRendererInterface
Chris@0:  * @see \Drupal\Core\Render\MainContentControllerPass
Chris@0:  */
Chris@0: class MainContentViewSubscriber implements EventSubscriberInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The class resolver service.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Controller\ControllerResolverInterface
Chris@0:    */
Chris@0:   protected $classResolver;
Chris@0: 
Chris@0:   /**
Chris@0:    * The current route match.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Routing\RouteMatchInterface
Chris@0:    */
Chris@0:   protected $routeMatch;
Chris@0: 
Chris@0:   /**
Chris@0:    * The available main content renderer services, keyed per format.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $mainContentRenderers;
Chris@0: 
Chris@0:   /**
Chris@0:    * URL query attribute to indicate the wrapper used to render a request.
Chris@0:    *
Chris@0:    * The wrapper format determines how the HTML is wrapped, for example in a
Chris@0:    * modal dialog.
Chris@0:    */
Chris@0:   const WRAPPER_FORMAT = '_wrapper_format';
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new MainContentViewSubscriber object.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\DependencyInjection\ClassResolverInterface $class_resolver
Chris@0:    *   The class resolver service.
Chris@0:    * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
Chris@0:    *   The current route match.
Chris@0:    * @param array $main_content_renderers
Chris@0:    *   The available main content renderer service IDs, keyed by format.
Chris@0:    */
Chris@0:   public function __construct(ClassResolverInterface $class_resolver, RouteMatchInterface $route_match, array $main_content_renderers) {
Chris@0:     $this->classResolver = $class_resolver;
Chris@0:     $this->routeMatch = $route_match;
Chris@0:     $this->mainContentRenderers = $main_content_renderers;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Sets a response given a (main content) render array.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent $event
Chris@0:    *   The event to process.
Chris@0:    */
Chris@0:   public function onViewRenderArray(GetResponseForControllerResultEvent $event) {
Chris@0:     $request = $event->getRequest();
Chris@0:     $result = $event->getControllerResult();
Chris@0: 
Chris@0:     // Render the controller result into a response if it's a render array.
Chris@0:     if (is_array($result) && ($request->query->has(static::WRAPPER_FORMAT) || $request->getRequestFormat() == 'html')) {
Chris@0:       $wrapper = $request->query->get(static::WRAPPER_FORMAT, 'html');
Chris@0: 
Chris@0:       // Fall back to HTML if the requested wrapper envelope is not available.
Chris@0:       $wrapper = isset($this->mainContentRenderers[$wrapper]) ? $wrapper : 'html';
Chris@0: 
Chris@0:       $renderer = $this->classResolver->getInstanceFromDefinition($this->mainContentRenderers[$wrapper]);
Chris@0:       $response = $renderer->renderResponse($result, $request, $this->routeMatch);
Chris@0:       // The main content render array is rendered into a different Response
Chris@0:       // object, depending on the specified wrapper format.
Chris@0:       if ($response instanceof CacheableResponseInterface) {
Chris@0:         $main_content_view_subscriber_cacheability = (new CacheableMetadata())->setCacheContexts(['url.query_args:' . static::WRAPPER_FORMAT]);
Chris@0:         $response->addCacheableDependency($main_content_view_subscriber_cacheability);
Chris@0:       }
Chris@0:       $event->setResponse($response);
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function getSubscribedEvents() {
Chris@0:     $events[KernelEvents::VIEW][] = ['onViewRenderArray'];
Chris@0: 
Chris@0:     return $events;
Chris@0:   }
Chris@0: 
Chris@0: }