Basic Symfony Controller demonstrating the use of a logical name for template - http://www.symfonycentral.com

BlogController.php

<?php
// src/MyCompany/BlogBundle/Controller/BlogController.php

namespace MyCompany\BlogBundle\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class BlogController extends Controller
{
    public function viewAction($id)
    {
        $post = $this->get('doctrine')
            ->getEntityManager()
            ->getRepository('MyCompanyBlogBundle:Post')
            ->find($id);

        // Use the logical name of the template
        return $this->render('MyCompanyBlogBundle:Blog:show.html.twig', array(
            'post' => $post,
        ));
    }
}