Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\EventSubscriber;
Chris@0: 
Chris@0: use Drupal\Core\State\StateInterface;
Chris@0: use Drupal\Core\Routing\RouteBuildEvent;
Chris@0: use Drupal\Core\Routing\RoutingEvents;
Chris@0: use Symfony\Component\EventDispatcher\EventSubscriberInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides all available first bits of all route paths.
Chris@0:  */
Chris@0: class PathRootsSubscriber implements EventSubscriberInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * Stores the path roots available in the router.
Chris@0:    *
Chris@0:    * A path root is the first virtual directory of a path, like 'admin', 'node'
Chris@0:    * or 'user'.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $pathRoots = [];
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:    * Constructs a new PathRootsSubscriber instance.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\State\StateInterface $state
Chris@0:    *   The state key value store.
Chris@0:    */
Chris@0:   public function __construct(StateInterface $state) {
Chris@0:     $this->state = $state;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Collects all path roots.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Routing\RouteBuildEvent $event
Chris@0:    *   The route build event.
Chris@0:    */
Chris@0:   public function onRouteAlter(RouteBuildEvent $event) {
Chris@0:     $collection = $event->getRouteCollection();
Chris@0:     foreach ($collection->all() as $route) {
Chris@0:       $bits = explode('/', ltrim($route->getPath(), '/'));
Chris@0:       $this->pathRoots[$bits[0]] = $bits[0];
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function onRouteFinished() {
Chris@0:     $this->state->set('router.path_roots', array_keys($this->pathRoots));
Chris@0:     $this->pathRoots = [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function getSubscribedEvents() {
Chris@0:     $events = [];
Chris@0:     // Try to set a low priority to ensure that all routes are already added.
Chris@0:     $events[RoutingEvents::ALTER][] = ['onRouteAlter', -1024];
Chris@0:     $events[RoutingEvents::FINISHED][] = ['onRouteFinished'];
Chris@0:     return $events;
Chris@0:   }
Chris@0: 
Chris@0: }