FormController.php

<?php
//src/Acme/FormBundle/Controller/FormController.php

namespace Acme\FormBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Acme\FormBundle\Entity\FormData;
use Symfony\Component\HttpFoundation\Request;

class FormController extends Controller
{
	public function formAction( Request $request )
	{
		$form = $this->getForm();
		if( 'POST' === $request->getMethod() )
		{
			$form->handleRequest( $request );
			if( $form->isValid() )
			{
				$this->handleData( $form->getData() );
				return new RedirectResponse( $this->generateUrl( 'custom_form_confirm' ) );
			}
		}

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

	private function getForm()
	{
		return $this->createForm( 'acme_custom_form' );
	}

	private function handleData( FormData $data )
	{
		...
	}

	...
}