public function getNextPosition($parentId)
    {
        $query = $this->getEntityManager()->createQuery('SELECT MAX(p.position) FROM FulgurioLightCMSBundle:Page p WHERE p.parent=:parentId AND p.page_type=:pageType');
        $query->setParameter('pageType', 'page');
        $query->setParameter('parentId', $parentId);
        return $query->getSingleScalarResult() + 1;
    }