protected function _initialize(){

    parent::_initialize();    //修改这里

    define('USER_ID', Session::get('user_id'));

}

  protected function isLogin()

  {

  if(empty(USER_ID)){

  $this->error('用户未登录，无权访问',url('user/login'));

  }

  }

  protected function alreadyLogin()

  {

  if(empty(USER_ID)){

  $this->error('用户已经登录，请勿重复登录',url('index/index'));

  }

  }

index.html:1 Error in event handler for (unknown): TypeError: Cannot read property 'parentNode' of undefined出现这个报错信息，谢谢帮忙