/**
  * Return url for iframe source
  *
  * @return string
  */
 public function getIframeSourceUrl()
 {
     if (!Mage_AdminNotification_Model_Survey::isSurveyUrlValid() || Mage::getSingleton('install/installer')->getHideIframe()) {
         return null;
     }
     return Mage_AdminNotification_Model_Survey::getSurveyUrl();
 }

 /**
  * Index Action
  *
  */
 public function indexAction()
 {
     if ($this->getRequest()->getParam('isAjax', false)) {
         Mage_AdminNotification_Model_Survey::saveSurveyViewed(true);
     }
     $this->getResponse()->setBody(Zend_Json::encode(array('survey_decision_saved' => 1)));
 }

 /**
  * Return survey url
  *
  * @return string
  */
 public function getSurveyUrl()
 {
     return Mage_AdminNotification_Model_Survey::getSurveyUrl();
 }

 /**
  * End installation
  */
 public function endAction()
 {
     $this->_checkIfInstalled();
     $date = (string) Mage::getConfig()->getNode('global/install/date');
     if ($date !== Mage_Install_Model_Installer_Config::TMP_INSTALL_DATE_VALUE) {
         $this->_redirect('*/*');
         return;
     }
     $this->_getInstaller()->finish();
     Mage_AdminNotification_Model_Survey::saveSurveyViewed(true);
     $this->_prepareLayout();
     $this->_initLayoutMessages('install/session');
     $this->getLayout()->getBlock('content')->append($this->getLayout()->createBlock('install/end', 'install.end'));
     $this->renderLayout();
     Mage::getSingleton('install/session')->clear();
 }

 /**
  * Return core flag model
  *
  * @return Mage_Core_Model_Flag
  */
 protected static function _getFlagModel()
 {
     if (self::$_flagModel === null) {
         self::$_flagModel = Mage::getModel('core/flag', array('flag_code' => self::$_flagCode))->loadSelf();
     }
     return self::$_flagModel;
 }