DNDataArchive::get_mode_map PHP Method

    public static function get_mode_map()
    {
        return array('all' => 'Database and Assets', 'db' => 'Database only', 'assets' => 'Assets only');
    }

 /**
  * @return Form
  */
 public function getDataTransferForm($request)
 {
     // Performs canView permission check by limiting visible projects
     $envs = $this->getCurrentProject()->DNEnvironmentList()->filterByCallback(function ($item) {
         return $item->canBackup();
     });
     if (!$envs) {
         return new SS_HTTPResponse("Environment '" . Convert::raw2xml($request->latestParam('Environment')) . "' not found.", 404);
     }
     $form = new Form($this, 'DataTransferForm', new FieldList(new HiddenField('Direction', false, 'get'), new DropdownField('EnvironmentID', 'Environment', $envs->map()), new DropdownField('Mode', 'Transfer', DNDataArchive::get_mode_map())), new FieldList(FormAction::create('doDataTransfer', 'Create')->addExtraClass('btn')));
     $form->setFormAction($request->getURL() . '/DataTransferForm');
     return $form;
 }