public function getLocationsUrlsMetaAction()
    {
        $qb = $this->getQueryBuilder();
        $qb->select('l.url');
        $qb->from('CampaignChain\CoreBundle\Entity\Channel', 'c');
        $qb->from('CampaignChain\CoreBundle\Entity\Location', 'l');
        $qb->where('c.id = l.channel');
        $qb->andWhere('l.operation IS NULL');
        $qb->groupBy(('l.url'));
        $query = $qb->getQuery();

        $urls = $query->getResult(\Doctrine\ORM\Query::HYDRATE_ARRAY);

        return $this->response(
            VariableUtil::arrayFlatten($urls)
        );
    }