getParameterNames example

  public function __construct($route_name, Route $route, array $parameters = [], array $raw_parameters = []) {
    $this->routeName = $route_name;
    $this->route = $route;

    // Pre-filter parameters.     $route_params = $this->getParameterNames();
    $parameters = array_intersect_key($parameters, $route_params);
    $raw_parameters = array_intersect_key($raw_parameters, $route_params);
    $this->parameters = new ParameterBag($parameters);
    $this->rawParameters = new InputBag($raw_parameters);
  }

  /** * Creates a RouteMatch from a request. * * @param \Symfony\Component\HttpFoundation\Request $request * A request object. * * @return \Drupal\Core\Routing\RouteMatchInterface * A new RouteMatch object if there's a matched route for the request. * A new NullRouteMatch object otherwise (e.g., on a 404 page or when * invoked prior to routing). */