Silex User Authentication and PHP ActiveRecord

app.php

<?php
/*
 * Put it in app.php
 */
use Silex\Provider\SecurityServiceProvider;

$app = new Silex\Application();

$app->register(new SecurityServiceProvider(), array(
    'security.firewalls' => array(
        'admin' => array(
            'pattern' => '^/',
            'form'    => array(
                'login_path'         => '/user/login',
                'username_parameter' => 'form[username]',
                'password_parameter' => 'form[password]',
                'check_path' => '/admin/login_check',
            ),
            'logout'    => true,
            'anonymous' => true,
            'users'     => $app->share(function() use ($app) {
                return new App\User\UserProvider();
            }),
        ),
    ),
));

/* ActiveRecord */
$app['ar.model_dir'] = __DIR__ . '/App/Model';
$app['ar.connections'] =  array (
            'development' => 'mysql://root@localhost/db_name'
        );

$app['ar.default_connection'] = 'development';

$app->register(new Ruckuus\Silex\ActiveRecordServiceProvider());

return $app;

login.html.twig

{% extends 'layout.html.twig' %}
{% set active = 'account' %}

{% block content %}

    <h1>{{ 'Login'|trans }}</h1>

    {% if error %}
        <div class="alert alert-error">
            {{ error }}
        </div>
        <div class="alert alert-info">
            <strong>Hint:</strong> Try <code>username</code>/<code>password</code>
        </div>

    {% endif %}

    <form action="{{ path('admin_login_check') }}" method="post" novalidate {{ form_enctype(form) }} class="form-vertical">
        {{ form_widget(form) }}
        <div class="form-actions">
            <button type="submit" class="btn btn-primary">{{ 'Send'|trans }}</button>
        </div>
    </form>

{% endblock %}

LoginControllerProvider.php

<?php
/*
 * Put it in App/Provider
 */
namespace App\Provider;

use Silex\Application;
use Silex\ControllerProviderInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

class LoginControllerProvider implements ControllerProviderInterface
{
    public function connect(Application $app) {
        $controllers = $app['controllers_factory'];

        $controllers->match('/', function() use ($app) {
           if (!$app['security']->isGranted('ROLE_USER')) {
                return $app->redirect('/user/login');
           } else {
                /* Redirect to user's account page */
                return $app->redirect($app['url_generator']->generate('homepage'));
           }
        });

        $controllers->match('/login', function(Request $request) use ($app) {
            $form = $app['form.factory']->createBuilder('form')
                    ->add('username', 'text', array('label' => 'Username', 'data' => $app['session']->get('_security.last_username')))
                    ->add('password', 'password', array('label' => 'Password'))
                    ->getForm()
                    ;

                    return $app['twig']->render('login.html.twig', array(
                        'form'  => $form->createView(),
                        'error' => $app['security.last_error']($request),
                        'last_username' => $app['session']->get('_security.last_username'),
                    ));
        })->bind('login');

        $controllers->match('/logout', function() use ($app) {
            $app['session']->clear();

            return $app->redirect($app['url_generator']->generate('homepage'));
        })->bind('logout');

        return $controllers;
    }
}

User.php

<?php
/*
 * Put it in App/Model
 */
namespace App\Model;

class User extends \ActiveRecord\Model
{
    static $connection = 'development';

    static $attr_accessible = array('username', 'password', 'roles');

    static $alias_attribute = array(
        'alias_username' => 'username',
        'alias_password' => 'password',
        'alias_roles' => 'roles',
        'alias_id' => 'id'
    );

    static $has_many = array(
        array('problem')
    );

    static $validates_presence_of = array(
        array('name'), array('roles')
    );
}

UserProvider.php

<?php
/*
 * Put it in App/User
 */
namespace App\User;

use Symfony\Component\Security\Core\User\UserProviderInterface;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Security\Core\User\User;
use Symfony\Component\Security\Core\Exception\UsernameNotFoundException;
use Symfony\Component\Security\Core\Exception\UnsupportedUserException;
use App\Model\User as BlogUser;

class UserProvider implements UserProviderInterface
{

    public function loadUserByUsername($username)
    {
        $user = BlogUser::find_by_username(strtolower($username));

        if ($user->count() < 1) {

            throw new UsernameNotFoundException(sprintf('Username "%s" does not exist.', $username));
        }

        if ($user->dirty_attributes()) {
            throw new UnsupportedUserException(sprintf('Bad credentials for "%s"'), $username);
        }

        return new User($user->alias_username, $user->alias_password, explode(',', $user->alias_roles), true, true, true, true);
    }

    public function refreshUser(UserInterface $user)
    {
        if (!$user instanceof User) {
            throw new UnsupportedUserException(sprintf('Instances of "%s" are not supported.', get_class($user)));
        }

        return $this->loadUserByUsername($user->getUsername());
    }

    public function supportsClass($class)
    {
        return $class === 'Symfony\Component\Security\Core\User\User';
    }
}