function perform()
 {
     // we can proceed to update the config
     foreach ($this->_newConfigOpts as $key => $value) {
         $this->_config->setValue($key, $value);
     }
     // and finally save everything
     $res = $this->_config->save();
     // depending on the result, we shall show one thing or another...
     if ($res) {
         $this->_view = new AdminGlobalSettingsListView($this->_blogInfo);
         $this->_view->setSuccessMessage($this->_locale->tr("site_config_saved_ok"));
         $this->setCommonData();
         // clear the contents of all the caches
         CacheControl::resetAllCaches();
     } else {
         $this->_view = new AdminGlobalSettingsListView($this->_blogInfo);
         $this->_view->setErrorMessage($this->_locale->tr("error_saving_site_config"));
         $this->setCommonData();
     }
     return $res;
 }