Controller.php

## composer.json
{
  "require": {
    "gedmo/doctrine-extensions": "dev-master"
  }
}

## config.yml
imports:
  - { resource: doctrine_extensions.yml }

## Controller.php
<?php

namespace Acme\DemoBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class MiControlador extends Controller
{
    public function eliminarAction()
    {
        $em = $this->getDoctrine()->getEntityManager();
        $entidad = $em->getRepository('DemoBundle:Entidad')->find(1); // suponemos que hay un Entidad id 1
        // $entidad existe
        $entidad->getDeletedAt(); // retorna NULL

        $em->remove($entidad);
        $em->flush();

        $entidad = $em->getRepository('DemoBundle:Entidad')->find(1);
        // $entidad ahora es NULL

        // desactivando el filtro softdeleteable, podremos retornar las entidades eliminadas anteriormente
        $em->getFilters()->disable('soft-deleteable');

        $entidad = $em->getRepository('DemoBundle:Entidad')->find(1);
        // $entidad vuelve a ser un objeto tipo Entidad
        $entidad->getDeletedAt(); // retorna un \DateTime
    }
}
?>

## doctrine_extensions.yml
services:
  extension.listener:
    class: Acme\DemoBundle\Listener\DoctrineExtensionListener
      calls:
        - [ setContainer, [ @service_container ] ]
      tags:
        - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }

  gedmo.listener.softdeleteable:
    class: Gedmo\SoftDeleteable\SoftDeleteableListener
      calls:
        - [ setAnnotationReader, [ @annotation_reader ] ]
      tags:
        - { name: doctrine.event_subscriber, connection: default }

## DoctrineExtensionListener.php
<?php
namespace Acme\DemoBundle\Listener;

use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\DependencyInjection\ContainerAwareInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

class DoctrineExtensionListener implements ContainerAwareInterface
{
    /**
     * @var ContainerInterface
     */
    protected $container;

    public function setContainer(ContainerInterface $container = null)
    {
        $this->container = $container;
    }

    public function onKernelRequest(GetResponseEvent $event)
    {
        $doctrine = $this->container->get('doctrine');
        $doctrine->getEntityManager()->getConfiguration()->addFilter(
            'soft-deleteable',
            'Gedmo\SoftDeleteable\Filter\SoftDeleteableFilter'
        );

        $em = $doctrine->getEntityManager();
        $em->getFilters()->enable('soft-deleteable');
    }
}
?>

## Entity.php
<?php

namespace Acme\DemoBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Gedmo\Mapping\Annotation as Gedmo;

/**
 * Entidad
 *
 * @ORM\Table()
 * @ORM\Entity()
 * @Gedmo\SoftDeleteable(fieldName="deletedAt")
 */
class Entidad
{
    // ...

    /**
     * @ORM\Column(name="deletedAt", type="datetime", nullable=true)
     */
    private $deletedAt;

    // ...
}
?>