Alter a route according the current user

Question

I'm on D 9.4.x, trying to redirect the node.add route to a custom one, only when the current user has the right role\permission.

So I don't think I can't work in the alterRoutes but I probably need to override the controller of that route. In a custom RouteSubscriber I have:

protected function alterRoutes(RouteCollection $collection) {
    if ($route = $collection->get('node.add')) {
      $route->setDefault('_controller', '\Drupal\my_module\myController::alterRoute');
    }
  }

and in the controller

  public function alterRoute(RouteMatchInterface $route_match) {
    if ($my_condition) {
       return $this->redirect('my_route');
    }
    else {
      $node_type = $route_match->getRawParameter('node_type');
      return $this->redirect('node.add', ['node_type' => $node_type]); //this goes loop
    }
  }

This code causes a loop, as when the condition fails the redirect return in my custom controller and so on. Any idea I could implement this feature? Thanks

Answer 1

Thanks to the comment of @4uk4 I've develop an Event Subscriber where is easy to implement the logic I need:

  public function onKernelRequest(RequestEvent $event) {
     if ($this->account->hasPermission('my permission')) {
      return;
    }

    $route_name = $this->routeMatch->getRouteName();
    
    if($route_name === 'node.add') {
     $url = Url::fromRoute('custom_route')->toString();
     $response = new RedirectResponse($url);
     $event->setResponse($response);
    }

  }