public function exportAction()
    {
        $em = $this->getDoctrine()->getManager();
        $chillSecurityHelper = $this->get('chill.main.security.authorization.helper');
        $user = $this->get('security.context')->getToken()->getUser();

        $reachableCenters = $chillSecurityHelper->getReachableCenters($user,
            new Role('CHILL_PERSON_SEE'));

        $personRepository = $em->getRepository('ChillPersonBundle:Person');
        $qb = $personRepository->createQueryBuilder('p');
        $qb->where($qb->expr()->in('p.center', ':centers'))
            ->setParameter('centers', $reachableCenters);
        $persons = $qb->getQuery()->getResult();

        $response = $this->render('ChillPersonBundle:Person:export.csv.twig',
            array(
                'persons' => $persons,
                'cf_group' => $this->getCFGroup()));
        $response->headers->set('Content-Type', 'text/csv; charset=utf-8');
        $response->headers->set('Content-Disposition', 'attachment; filename="export_person.csv"');

        return $response;
    }