CodeIgniter库:访问CodeIgniter SuperObject的访问导致PHP严重性错误:注意

Question

我有一个代码签名库。当我从控制器访问它时，严重性的PHP错误：引起了通知。但是，调试器表明超级对象存在于库中，是CI超级对象。

这是库类：

    class Auth_lib {
    protected $CI;
    public function __construct()
    {
        $this->$CI =& get_instance();
        $this->$CI->load->model('auth_model');
        $this->$CI->load->library('session');
    }
    /**
     * checks if the current user is logged into a session
     * @param 
     * @return boolean 
     */
     public function is_logged_in(){
        $result = $this->$CI->session->userdata('is_logged_in');
        return $result;
    }
}

这就是我的控制器调用库的方式：

        public function __construct()
        {
            parent::__construct();
            $this->load->helper('url_helper');
            $this->load->library('auth_lib');
            // test if user is logged in and authorised, if not redirect to login controller
            if($this->auth_lib->is_logged_in() != null){
                // check if is admin
                }
            } else {
                // not logged in, redirect to login controller
            }
        }

所以，为什么我会遇到此错误：

遇到了PHP错误 严重性：注意 消息：未定义的变量：CI 文件名：库/auth_lib.php 行号：20

Answer 1

1. 使用$this->CI代替$this->$CI。

2. return isset($result)?TRUE:FALSE;来自库的is_logged_in()函数。

   libraries/auth_lib.php

   class Auth_lib {
     protected $CI;
     public function __construct()
     {
       $this->CI =& get_instance();
       $this->CI->load->model('auth_model');
       $this->CI->load->library('session');
     }
   /**
    * checks if the current user is logged into a session
    * @param 
    * @return boolean 
    */
      public function is_logged_in(){
        $result = $this->CI->session->userdata('is_logged_in');
        return isset($result)?TRUE:FALSE;//make sure that you have set  session or not
      }
   }
   

   控制器

   public function __construct()
       {
           parent::__construct();
           $this->load->helper('url_helper');
           $this->load->library('auth_lib');
           // test if user is logged in and authorised, if not redirect to login controller
           if($this->auth_lib->is_logged_in()){
               // check if is admin
               }
           else {
               // not logged in, redirect to login controller
           }
       }