Symfony 2 redirecting out of private function - php

Question

In my Application I'm using a init function to init an action
the init function validate the user input
(for example the user is looking for an product what not exist -> the init function should redirect him to an errorpage "product ... not found")
/**
* #Route("/route/{var}", name="xyzbundle_xyz_index")
* #Template("VendorXyzBundle:xyz:index.html.twig")
*/
public function indexAction ($var)
{
$xyz = $this->initxyz($var);
...
.. more code
.
}
And there is a private function in this controller that should validate the from url given parameter and if it is wrong (dont exist in database etc), the private function should redirect
private function init($var)
{
if($this->databasesearchforexyz($var)){
// redirect to Errorpage (No xyz found named ...)
return $this->redirect($this->generateUrl('xyz_error_...'));
}
if($this->checksomethingelse($var)){
// redirect to some other error page
}
}
Please note, these are not my real method/variable/path/etc. names.
The problem is, it is not redirecting.

Answer 1

You can check if the init function returns an actual response, then you can return it directly from the main code. Like this:
public function indexAction ($var)
{
$xyz = $this->initxyz($var);
if ($xyz instanceof \Symfony\Component\HttpFoundation\Response) {
return $xyz;
}
...
.. more code
.
}
Btw, if you only need to check database existance you can use symfony's paramconverter

Answer 2

Here's some suggestion.
Return true from the init function if there's no redirect and return false if there's a redirect.
Example:
private function init($var) {
if ($error) {
// An error occurred, redirect
$this->redirect($this->generateUrl('xyz_error_...'));
return false;
}
// Else, everything alright
return true;
}
public function indexAction ($var) {
if (!$this->init($var)) {
// Failed to init, redirection happening
return;
}
// Continue as normal
}

Answer 3

Using the answer of #alex88, I aggregate an exception and an exception listener to do the redirect. That avoid me to repeat the condition over and over again, because my function could redirect the user under different scenarios.
1. Controller
namespace AppBundle\Controller;
use AppBundle\Exception\UserHasToBeRedirectedException;
class DefaultController extends Controller
{
public function indexAction(...)
{
...
$this->userHasToBeRedirected();
...
}
private function userHasToBeRedirected()
{
...
if ($userHasToBeRedirected) {
$response = $this->redirect($this->generateUrl(...));
throw new UserHasToBeRedirectedException($response);
}
...
}
}
2. Exception
namespace AppBundle\Exception;
use Exception;
use Symfony\Component\HttpFoundation\Response;
class UserHasToBeRedirectedException extends Exception
{
private $response;
public function __construct(Response $response)
{
$this->response = $response;
}
public function getResponse()
{
return $this->response;
}
public function setResponse(Response $response)
{
$this->response = $response;
return $this;
}
}
3. Exception Listener
namespace AppBundle\EventListener;
use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use AppBundle\Exception\UserHasToBeRedirectedException;
class ExceptionListener
{
public function onKernelException(GetResponseForExceptionEvent $event)
{
$exception = $event->getException();
...
if ($exception instanceof UserHasToBeRedirectedException) {
$response = $exception->getResponse();
$event->setResponse($response);
}
...
}
}
4. Register the service at service.yml
...
appBundle.exception_listener:
class: AppBundle\EventListener\ExceptionListener
tags:
- { name: kernel.event_listener, event: kernel.exception }
...
For more information:
Symfony Documantation about Events