Redirect from exception

app\config\services.yml

services:
    kernel.listener.redirectexception:
        class: AppBundle\EventListener\RedirectExceptionListener
        arguments:
            - "@router"
        tags:
            - { name: kernel.event_listener, event: kernel.exception }

app\Resources\views\default\login_form.html.twig

{{ render(controller('AppBundle:Default:login')) }}

src\AppBundle\Controller\DefaultController.php

<?php

namespace AppBundle\Controller;

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use AppBundle\Exception\RedirectException;

class DefaultController extends Controller
{
    /**
     * @Route("/", name="homepage")
     */
    public function indexAction(Request $request)
    {
        return $this->render('default/index.html.twig', [
            'base_dir' => realpath($this->getParameter('kernel.project_dir')).DIRECTORY_SEPARATOR,
        ]);
    }
    
    /**
     * @Route("/login", name="login")
     */
    public function loginAction(Request $request)
    {
        if ($this->getUser()) {
          throw new RedirectException('This user does not have access to this section.');
        }

        return $this->render('default/login.html.twig', []);
    }
    
    /**
     * @Route("/login_form", name="login_form")
     */
    public function loginFormAction(Request $request)
    {
        return $this->render('default/login_form.html.twig', []);
    }
}

src\AppBundle\EventListener\RedirectExceptionListener.php

<?php

namespace AppBundle\EventListener;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpFoundation\RedirectResponse;
use AppBundle\Exception\RedirectException;
use Symfony\Component\Routing\RouterInterface;

class RedirectExceptionListener
{
    private $router;
  
    public function __construct(RouterInterface $router)
    {
        $this->router = $router;
    }
    
    public function onKernelException(GetResponseForExceptionEvent $event)
    {
        if ((!$event->getException()->getPrevious() instanceof RedirectException)
              && (!$event->getException() instanceof RedirectException)) {
            return;
        }

        $response = new RedirectResponse($this->router->generate('homepage'));
        $event->setResponse($response);
    }
    
}