Symfony\Component\HttpFoundation\Request::getSession PHP Method

    public function getSession()
    {
        return $this->session;
    }

 /**
  * @Route("/taches/edition/{slug}")
  * @Template()
  */
 public function editAction($slug, Request $request)
 {
     if (!empty($slug)) {
         $session = $request->getSession();
         //0 valeur par defaut si vide
         $id_user = $session->get('user', 0);
         if ($id_user == 0) {
             $request->getSession()->getFlashBag()->add('error', 'OULAH ! Il s\'est passé un truc pas net O.o. Tu t\'es déco ?');
             return $this->redirect($this->generateUrl('corvee_taches_homepage', array()));
         }
         $em = $this->getDoctrine()->getManager();
         $tache = $em->getRepository('Corvees\\TachesBundle\\Entity\\Tache')->findOneBySlug($slug);
         if (!empty($tache)) {
             $user = $em->getRepository('Corvees\\TachesBundle\\Entity\\User')->find($id_user);
             $tache->setFkIntervenant($user);
             $tache->setDateEffectue(new \Datetime());
             $form = $this->get('form.factory')->create(new TacheEditType(), $tache);
             if ($form->handleRequest($request)->isValid()) {
                 $difference = $tache->getDateCreation()->diff($tache->getDateEffectue());
                 $difference = $difference->format("%Y-%m-%d %H:%i:%s");
                 $difference = new \DateTime($difference);
                 $tache->setTemps($difference);
                 $em = $this->getDoctrine()->getManager();
                 $em->persist($tache);
                 $em->flush();
                 $request->getSession()->getFlashBag()->add('notice', 'Tache bien enregistrée.');
                 return $this->redirect($this->generateUrl('corvee_taches_homepage', array()));
             }
             return array('form' => $form->createView(), 'tache' => $tache, 'route' => 'formulaire_tache_edit');
         }
     }
 }