Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Routing;
Chris@0: 
Chris@0: use Drupal\Core\Cache\Cache;
Chris@0: use Drupal\Core\Cache\CacheBackendInterface;
Chris@0: use Drupal\Core\State\StateInterface;
Chris@0: use Symfony\Component\EventDispatcher\Event;
Chris@0: use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0: use Symfony\Component\HttpKernel\Event\KernelEvent;
Chris@0: use Symfony\Component\HttpKernel\KernelEvents;
Chris@0: 
Chris@0: /**
Chris@0:  * Defines a class which preloads non-admin routes.
Chris@0:  *
Chris@0:  * On an actual site we want to avoid too many database queries so we build a
Chris@0:  * list of all routes which most likely appear on the actual site, which are all
Chris@0:  * HTML routes not starting with "/admin".
Chris@0:  */
Chris@0: class RoutePreloader implements EventSubscriberInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The route provider.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Routing\RouteProviderInterface|\Drupal\Core\Routing\PreloadableRouteProviderInterface
Chris@0:    */
Chris@0:   protected $routeProvider;
Chris@0: 
Chris@0:   /**
Chris@0:    * The state key value store.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\State\StateInterface
Chris@0:    */
Chris@0:   protected $state;
Chris@0: 
Chris@0:   /**
Chris@0:    * Contains the non-admin routes while rebuilding the routes.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $nonAdminRoutesOnRebuild = [];
Chris@0: 
Chris@0:   /**
Chris@0:    * The cache backend used to skip the state loading.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Cache\CacheBackendInterface
Chris@0:    */
Chris@0:   protected $cache;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new RoutePreloader.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Routing\RouteProviderInterface $route_provider
Chris@0:    *   The route provider.
Chris@0:    * @param \Drupal\Core\State\StateInterface $state
Chris@0:    *   The state key value store.
Chris@0:    * @param \Drupal\Core\Cache\CacheBackendInterface $cache
Chris@0:    */
Chris@0:   public function __construct(RouteProviderInterface $route_provider, StateInterface $state, CacheBackendInterface $cache) {
Chris@0:     $this->routeProvider = $route_provider;
Chris@0:     $this->state = $state;
Chris@0:     $this->cache = $cache;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Loads all non-admin routes right before the actual page is rendered.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\HttpKernel\Event\KernelEvent $event
Chris@0:    *   The event to process.
Chris@0:    */
Chris@0:   public function onRequest(KernelEvent $event) {
Chris@0:     // Only preload on normal HTML pages, as they will display menu links.
Chris@0:     if ($this->routeProvider instanceof PreloadableRouteProviderInterface && $event->getRequest()->getRequestFormat() == 'html') {
Chris@0: 
Chris@0:       // Ensure that the state query is cached to skip the database query, if
Chris@0:       // possible.
Chris@0:       $key = 'routing.non_admin_routes';
Chris@0:       if ($cache = $this->cache->get($key)) {
Chris@0:         $routes = $cache->data;
Chris@0:       }
Chris@0:       else {
Chris@0:         $routes = $this->state->get($key, []);
Chris@0:         $this->cache->set($key, $routes, Cache::PERMANENT, ['routes']);
Chris@0:       }
Chris@0: 
Chris@0:       if ($routes) {
Chris@0:         // Preload all the non-admin routes at once.
Chris@0:         $this->routeProvider->preLoadRoutes($routes);
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Alters existing routes for a specific collection.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Routing\RouteBuildEvent $event
Chris@0:    *   The route build event.
Chris@0:    */
Chris@0:   public function onAlterRoutes(RouteBuildEvent $event) {
Chris@0:     $collection = $event->getRouteCollection();
Chris@0:     foreach ($collection->all() as $name => $route) {
Chris@0:       if (strpos($route->getPath(), '/admin/') !== 0 && $route->getPath() != '/admin') {
Chris@0:         $this->nonAdminRoutesOnRebuild[] = $name;
Chris@0:       }
Chris@0:     }
Chris@0:     $this->nonAdminRoutesOnRebuild = array_unique($this->nonAdminRoutesOnRebuild);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Store the non admin routes in state when the route building is finished.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\EventDispatcher\Event $event
Chris@0:    *   The route finish event.
Chris@0:    */
Chris@0:   public function onFinishedRoutes(Event $event) {
Chris@0:     $this->state->set('routing.non_admin_routes', $this->nonAdminRoutesOnRebuild);
Chris@0:     $this->nonAdminRoutesOnRebuild = [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function getSubscribedEvents() {
Chris@0:     // Set a really low priority to catch as many as possible routes.
Chris@0:     $events[RoutingEvents::ALTER] = ['onAlterRoutes', -1024];
Chris@0:     $events[RoutingEvents::FINISHED] = ['onFinishedRoutes'];
Chris@0:     // Load the routes before the controller is executed (which happens after
Chris@0:     // the kernel request event).
Chris@0:     $events[KernelEvents::REQUEST][] = ['onRequest'];
Chris@0:     return $events;
Chris@0:   }
Chris@0: 
Chris@0: }