class RouteSubscriber

class RouteSubscriber implements EventSubscriberInterface {

  /**
   * The plugin manager for REST plugins.
   *
   * @var \Drupal\rest\Plugin\Type\ResourcePluginManager
   */
  protected $manager;

  /**
   * The Drupal configuration factory.
   *
   * @var \Drupal\Core\Config\ConfigFactory
   */
  protected $config;

  /**
   * Constructs a RouteSubscriber object.
   *
   * @param \Drupal\rest\Plugin\Type\ResourcePluginManager $manager
   *   The resource plugin manager.
   * @param \Drupal\Core\Config\ConfigFactory $config
   *   The configuration factory holding resource settings.
   */
  public function __construct(ResourcePluginManager $manager, ConfigFactory $config) {
    $this->manager = $manager;
    $this->config = $config;
  }

  /**
   * Adds routes to enabled REST resources.
   *
   * @param \Drupal\Core\Routing\RouteBuildEvent $event
   *   The route building event.
   */
  public function dynamicRoutes(RouteBuildEvent $event) {
    $collection = $event
      ->getRouteCollection();
    $resources = $this->config
      ->get('rest')
      ->load()
      ->get('resources');
    if ($resources && ($enabled = array_intersect_key($this->manager
      ->getDefinitions(), $resources))) {
      foreach ($enabled as $key => $resource) {
        $plugin = $this->manager
          ->getInstance(array(
          'id' => $key,
        ));

        // @todo Switch to ->addCollection() once http://drupal.org/node/1819018 is resolved.
        foreach ($plugin
          ->routes() as $name => $route) {
          $route
            ->setRequirement('_access', 'TRUE');
          $collection
            ->add("rest.{$name}", $route);
        }
      }
    }
  }

  /**
   * Implements EventSubscriberInterface::getSubscribedEvents().
   */
  static function getSubscribedEvents() {
    $events[RoutingEvents::DYNAMIC] = 'dynamicRoutes';
    return $events;
  }

}