Symfony Custom Error Page By Overriding ExceptionController

Question

what I am trying to do is to have custom error page, not only will they be extending the base layout but also I want extra up selling content in those pages too so changing templates only is not an option

regardless of the reason (404 Not Found or just missing variable) I would like to show my template and my content instead

I have spent hours trying to get this going with no luck

app/console --version
Symfony version 2.5.6 - app/dev/debug

I tried some resources, but couldn't get it working. The name a few:

http://symfony.com/doc/current/reference/configuration/twig.html http://symfony.com/doc/current/cookbook/controller/error_pages.html

I'm running in dev with no debug, see app_dev.php below:

$kernel = new AppKernel('dev', false);

following the tutorials i got these extra bits

app/config/config.yml

twig:
    exception_controller:  SomethingAppBundle:Exception:show

in my bundle

<?php

namespace Something\AppBundle\Controller;

use Symfony\Component\HttpKernel\Log\DebugLoggerInterface;
use Symfony\Component\HttpKernel\Exception\FlattenException;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class ExceptionController extends Controller
{
    public function showAction( FlattenException $error, DebugLoggerInterface $debug)
    {
        print_r($error);
    }

}

but my error controller does not get executed,

I am on purpose causing error by trying to echo undefined variable in different controller, since it should handle error from entire application

Answer 1

At the beginning you need to create action in the controller:

<?php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class ErrorController extends Controller
{
    
    public function notFoundAction()
    {
        return $this->render('error/404.html.twig');
    }
}

Then you need to create a Listener:

<?php
namespace AppBundle\EventListener;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\HttpKernel\HttpKernelInterface;

class NotFoundHttpExceptionListener
{
    private $controller_resolver;
    private $request_stack;
    private $http_kernel;

    public function __construct($controller_resolver, $request_stack, $http_kernel)
    {
        $this->controller_resolver = $controller_resolver;
        $this->request_stack = $request_stack;
        $this->http_kernel = $http_kernel;
    }
    public function onKernelException(GetResponseForExceptionEvent $event)
    {

        if ($event->getException() instanceof NotFoundHttpException) {

            $request = new \Symfony\Component\HttpFoundation\Request();
            $request->attributes->set('_controller', 'AppBundle:Error:notFound');
            $controller = $this->controller_resolver->getController($request);

            $path['_controller'] = $controller;
            $subRequest = $this->request_stack->getCurrentRequest()->duplicate(array(), null, $path);

            $event->setResponse($this->http_kernel->handle($subRequest, HttpKernelInterface::MASTER_REQUEST)); // Simulating "forward" in order to preserve the "Not Found URL"

        }
    }
}

Now register the service:

#AppBundle/Resources/config/services.yml
services:
    kernel.listener.notFoundHttpException:
            class: AppBundle\EventListener\NotFoundHttpExceptionListener
            tags:
                - { name: kernel.event_listener, event: kernel.exception, method: onKernelException, priority: -10 }
            arguments: [ @controller_resolver, @request_stack, @http_kernel ]

Not tested this, but rather it should work;)

EDIT:

Tested, it works. On the rendered page, you have a session, so you have access to app.user, his cart, and other matters related to the session.