public function exportAction() {
        $mem = new Garp_Util_Memory();
        $mem->useHighMemory();

        $params = new Garp_Util_Configuration($this->getRequest()->getParams());
        // make sure some required parameters are in place
        $params->obligate('exporttype')
            ->obligate('model')
            ->obligate('selection')
            ->setDefault('fields', Zend_Db_Select::SQL_WILDCARD);

        // fetch exporter
        $exporter = Garp_Content_Export_Factory::getExporter($params['exporttype']);
        $bytes = $exporter->getOutput($params);
        $filename = $exporter->getFilename($params);

        $download = Zend_Controller_Action_HelperBroker::getStaticHelper('download');
        $download->force($bytes, $filename, $this->_response);
        $this->_helper->viewRenderer->setNoRender();
    }