Symfony2 + AngularJS de-authentification handling

nav.js

var app = angular.module('nav', [])
    /*
        Finally, we add to our module configuration an Interceptor.
        This function will be called every time a request is made using $http or higher level services ($resource...).
        This code is for Angular 1.0.7, it seems $httpProvider.responseInterceptors is deprecated in 1.1.X (but still working).
        Consider using Interceptors in 1.1.X, http://docs.angularjs.org/api/ng.$http
    */
    .config(function($httpProvider) {
        function loginInterceptor($q, $window) {
            function success(response) {
                return response;
            }

            function error(response) {
                if (response.status == 401) {
                    // refresh page if user is de-logged
                    $window.location.reload();
                }

                return $q.reject(response);
            }

            return function (promise) {
                return promise.then(success, error);
            }
        }

        $httpProvider.responseInterceptors.push(loginInterceptor);
    })
;

services.xml

<!-- services config file - declare our event subscriber -->
<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
    <services>
        <service id="acme.listener.unauthorized_ajax" class="Acme\DemoBundle\EventListener\UnauthorizedAjaxListener">
            <tag name="kernel.event_subscriber" />
        </service>
    </services>
</container>

UnauthorizedAjaxListener.php

<?php

namespace Acme\DemoBundle\EventListener;

use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\Security\Core\Exception\AuthenticationException;

/*
    By default, Symfony2 redirects unauthentificated requests, event XMLHttp ones (AJAX),
    to the login form (302 redirects, AngularJS will automatically follow).
    We  make them send a 401 (unauthorized) error, so we can catch those in Javascript.
*/
class UnauthorizedAjaxListener implements EventSubscriberInterface
{
    public static function getSubscribedEvents()
    {
        return array(
            KernelEvents::EXCEPTION => array(
                'onKernelException', 10
            )
        );
    }

    public function onKernelException(GetResponseForExceptionEvent $event)
    {
        $exception = $event->getException();
        $request = $event->getRequest();

        // determine the actual cause for the exception
        while (null !== $previous = $exception->getPrevious()) {
            $exception = $previous;
        }

        // here is our custom logic
        if ($exception instanceof AuthenticationException && $request->isXmlHttpRequest()) {
            $event->setResponse(new Response('', 401));
        }
    }
}