public function processRequest($function = null)
    {
        if ($function) {
            $this->$function();
            $this->dispatchEvent(new AfterRequestProcessedEvent);
        } else {
            $sQAdd = $this->_getQuery();

            // formatting SQL queries
            $sQ = $this->_getDataQuery($sQAdd);
            $sCountQ = $this->_getCountQuery($sQAdd);

            $this->_outputResponse($this->_getData($sCountQ, $sQ));
        }
    }