/**
  * Display list of all users in json format
  *
  * @param string $search - username
  * @return mixed
  */
 public function actionUserList($search = null, $id = null)
 {
     $out = ['more' => false];
     if (!is_null($search)) {
         $query = new Query();
         $query->select('id, username AS text')->from(User::tableName())->where(['like', 'username', $search])->limit(20);
         $command = $query->createCommand();
         $data = $command->queryAll();
         $out['results'] = array_values($data);
     } elseif ($id > 0) {
         $out['results'] = ['id' => $id, 'text' => $this->findModel($id)->username];
     } else {
         $out['results'] = ['id' => 0, 'text' => 'No matching records found'];
     }
     echo Json::encode($out);
 }