Symfony ParamConverter for lookup user by `me`

UserParamConverter.php

<?php
/**
 * @author  Almog Baku
 *          [email protected]
 *          http://www.GoDisco.net/
 *
 * 10/05/15 18:43
 */

namespace Rimoto\SubscriberBundle\Request\ParamConverter;

use Doctrine\Common\Persistence\ManagerRegistry;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
use Sensio\Bundle\FrameworkExtraBundle\Request\ParamConverter\DoctrineParamConverter;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\HttpKernel\Exception\UnauthorizedHttpException;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorage;

class UserParamConverter extends DoctrineParamConverter
{
    /** @var TokenStorage */
    private $storage;

    /**
     * Constructor
     * @param TokenStorage $storage
     * @param ManagerRegistry $registry
     */
    public function __construct(ManagerRegistry $registry = null, TokenStorage $storage)
    {
        parent::__construct($registry);
        $this->storage = $storage;
    }

    /**
     * {@inheritdoc}
     *
     * @throws \LogicException       When unable to guess how to get a Doctrine instance from the request information
     * @throws NotFoundHttpException When object not found
     */
    public function apply(Request $request, ParamConverter $configuration)
    {
        $name = $configuration->getName();
        $options = $this->getOptions($configuration);
        $id = $this->getIdentifier($request, $options, $name);
        if(is_string($id) && strtolower($id) === "me") {
            $token = $this->storage->getToken();
            if ($token === null) {
                throw new BadRequestHttpException('Token not found.');
            }
            $user = $token->getUser();
            if (!is_object($user)) {
                throw new UnauthorizedHttpException("`me` is not valid for anonymous");
            }
            $request->attributes->set($configuration->getName(), $user);
            return true;
        }
        return parent::apply($request, $configuration);
    }

    /**
     * @param ParamConverter $configuration
     * @return bool
     */
    public function supports(ParamConverter $configuration)
    {
        if (null === $this->registry || !count($this->registry->getManagers())) {
            return false;
        }

        // Check, if option class was set in configuration
        if (null === $configuration->getClass()) {
            return false;
        }

        // Get actual entity manager for class
        $em = $this->registry->getManagerForClass($configuration->getClass());

        // Check, if class name is what we need
        $class = $em->getClassMetadata($configuration->getClass())->getName();
        $interfaces = class_implements($class);
        return in_array('Symfony\Component\Security\Core\User\UserInterface', $interfaces);
    }
}