SocialWallApp.php

<?php

use Silex\Application;
use Demo\Repository\PostRepository;

$app = new Application();

$app['dao.article'] = function() {
  // $app['db'] def and $app['dao.user'] defined elsewhere
  $articleDAO = new ArticleDAO($app['db']);
  $articleDAO->setUserDAO($app['dao.user']);
  return $articleDAO;
};

$app['home.controller'] = function() use ($app) {
    return new HomeController($app['dao.article']);
};

$app->get('/', "home.controller:indexAction");