Redirects unauthenticated users to login

AuthenticationListener.php

<?php

namespace MyApp\Authentication;

use Zend\EventManager\AbstractListenerAggregate;
use Zend\EventManager\EventManagerInterface;
use Zend\Mvc\MvcEvent;
use Zend\Stdlib\ResponseInterface;

/**
 * Redirects unauthenticated users to login
 */
class AuthenticationListener extends AbstractListenerAggregate
{
    /**
     * {@inheritDoc}
     */
    public function attach(EventManagerInterface $events)
    {
        $this->listeners[] = $events->attach(MvcEvent::EVENT_ROUTE, [$this, 'onRoute'], 500);
    }

    /**
     * @param  MvcEvent               $e
     * @return void|ResponseInterface
     */
    public function onRoute(MvcEvent $e)
    {
        $routeMatch = $e->getRouteMatch();

        if (!$routeMatch) {
            return;
        }

        if ($routeMatch->getMatchedRouteName() === 'login') {
            return;
        }

        $services    = $e->getApplication()->getServiceManager();
        $authService = $services->get('Zend\Authentication\AuthenticationService');

        if ($authService->hasIdentity()) {
            return;
        };

        $response = $e->getResponse();
        $url      = $e->getRouter()->assemble([], ['name' => 'login']);

        $response->setStatusCode(302);
        $response->getHeaders()->addHeaderLine('Location', $url);

        return $response;
    }
}