public function renderDataTableJson()
    {
        $res = array();
        $render = $this->getTable()->getRow()->renderRows('array');
        $res['sEcho'] = $render;
        $res['iTotalDisplayRecords'] = $this->getTable()->getSource()->getPaginator()->getTotalItemCount();
        $res['aaData'] = $render;

        return json_encode($res);
    }