A complete example of a CRUD manager implementation in a controller.

DefaultController.php

<?php

namespace Martial\LabBundle\Controller;

use Martial\CrudBundle\Exception\CrudException;
use Martial\LabBundle\Entity\Article;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class DefaultController extends Controller
{
    /**
     * Get the article list
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function indexAction()
    {
        $articles = $this->getCrudManager()->getRepository()->findAll();

        return $this->render('MartialLabBundle:Default:index.html.twig', array('articles' => $articles));
    }

    /**
     * Show an article
     *
     * @param int $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function showAction($id)
    {
        $article = $this->findArticle($id);

        return $this->render('MartialLabBundle:Default:show.html.twig', array('article' => $article));
    }

    /**
     * Display a form to create an article
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function newAction()
    {
        $form = $this->getCrudManager()->createForm();

        return $this->render('MartialLabBundle:Default:new.html.twig', array('form' => $form->createView()));
    }

    /**
     * Save a new article
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function createAction()
    {
        return $this->saveArticle();
    }

    /**
     * Edit an existing article
     *
     * @param int $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function editAction($id)
    {
        $article = $this->findArticle($id);
        $form = $this->getCrudManager()->createForm($article);

        return $this->render('MartialLabBundle:Default:edit.html.twig', array(
                'form' => $form->createView(),
                'article' => $article
            )
        );
    }

    /**
     * Update an article
     *
     * @param int $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function updateAction($id)
    {
        $article = $this->findArticle($id);

        return $this->saveArticle($article);
    }

    /**
     * Delete an article
     *
     * @param int $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function deleteAction($id)
    {
        $article = $this->findArticle($id);
        $this->getCrudManager()->delete($article);

        return $this->redirect($this->generateUrl('martial_lab_homepage'));
    }

    /**
     * Find an article
     *
     * @param int $id
     * @return object
     * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
     */
    private function findArticle($id)
    {
        $article = $this->getCrudManager()->find($id);

        if (!$article) {
            throw $this->createNotFoundException('Article not found');
        }

        return $article;
    }

    /**
     * Return the CRUD manager
     *
     * @return \Martial\CrudBundle\Manager\CrudManagerInterface
     */
    private function getCrudManager()
    {
        return $this->get('martial.crud')->getCrudManager('article');
    }

    /**
     * Save an article
     *
     * @param Article $article
     * @return \Symfony\Component\HttpFoundation\Response
     */
    private function saveArticle($article = null)
    {
        try {
            $this->getCrudManager()->saveForm($article);

            return $this->redirect($this->generateUrl('martial_lab_show', array(
                        'id' => $article->getId()
                    )
                )
            );
        } catch (CrudException $e) {
            return $this->render('MartialLabBundle:Default:edit.html.twig', array(
                    'form' => $this->getCrudManager()->getCurrentForm()->createView(),
                    'article' => $this->getCrudManager()->getCurrentEntity()
                )
            );
        }
    }
}