Symfony2 Custom Error Exception Listener - Rendering templates or passing to a controller

3
votes

I'm trying to work out the best way of handling custom error pages within Symfony2.This includes 500 and 404's etc.

I can create my own custom templates (error404.html.twig etc) and render these out fine, the issue is , the app requires a few variables be passed into the base template for the page to remain consistent. Using the built in exception handler results in required variables not being available.

I have successfully setup a custom Exception Event Listener, and registered it as a service:

namespace MyCo\MyBundle\Listener;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Bundle\TwigBundle\TwigEngine;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template;



class MyErrorExceptionListener
{

    public function onKernelException(GetResponseForExceptionEvent $event)
    {
        // We get the exception object from the received event
        $exception = $event->getException();

        if($exception->getStatusCode() == 404)
        {

            //$engine = $this->container->get('templating');
            //$content = $engine->render('MyBundle:Default:error404.html.twig');    
            //return $response = new Response($content);

            /* Also Tried */
            //$templating = $this->container->get('templating');    
            //return $this->render('MyBundle:Default:index.html.twig');



            $response = new Response($templating->render('MyBundle:Exception:error404.html.twig', array(
                    'exception' => $exception
            )));

            $event->setResponse($response);

        }


    }
}

This doesn't work , as :$container is not available , meaning I cannot render my custom page.

So two questions really , is this the correct way to handle custom error pages, or should I pass the response off to a controller? If so , whats the best way of doing that?

If this is correct , how can I make the templating engine available within my Listener ?

2
symfonytwig

2 Answers

9
votes

You should add into yours Listener

/**
 *
 * @var ContainerInterface
 */
private $container;

function __construct($container) {
    $this->container = $container;
}

How do you register your Listener? You should register Listener like Service

Like that

core.exceptlistener:
  class: %core.exceptlistener.class%
  arguments: [@service_container]
  tags:
        - { name: kernel.event_listener, event: kernel.exception, method: onKernelException, priority: 200 }

The best way is don't use service_container. The best way is register only necessary services.

Like that

/**
 *
 * @var Twig_Environment
 */
private $twig;

function __construct($twig) {
    $this->twig = $twig;
}
0
votes

The way I did to solve similar issue is: I dont know if it can help you out.

const GENERIC_CODE = 550;
public function onKernelException(GetResponseForExceptionEvent $event)
{
    $exception = $event->getException();
    if ($exception instanceof RedirectableException) {
        $request = $event->getRequest();
        $url = $exception->getUrl($this->_authentication['base']['url']);
        $response = new Response();
        $response->setStatusCode(self::GENERIC_CODE, AuthenticationException::GENERIC_MESSAGE);
        $response->setContent($url);
        $event->setResponse($response);
   }
}