/**
  * save template of checklist along with some information to db
  * @return json content checklist
  */
 public function actionSavecontent()
 {
     $post = Yii::$app->request->post();
     $id = $post['id'];
     $content = $post['content'];
     if ($id && $content) {
         $checklistCow = ChecklistsCow::findOne($id);
         $checklistCow->content = $content;
         // save whole change to db
         if ($checklistCow->save()) {
             Yii::$app->response->format = 'json';
             return ['errors' => '', 'data' => ''];
         }
     }
     return;
 }