003-ci using CodeIgniter resources in your class library

Use the get_instance () function in your class library to access the native resources of CodeIgniter, which returns the CodeIgniter super object.

Typically, in your controller method you will use the $this to invoke all available CodeIgniter methods:

$this->load->helper (' url '), $this->load->library (' Session '), $this->config->item (' Base_url '); /etc.

But $this can only be used directly in your controller, model, or view, if you want to use the CodeIgniter class in your own class, you can do the following:

First, assign the CodeIgniter object to a variable:

$CI =& get_instance ();

Once you have assigned the CodeIgniter object to a variable, you can use this variable to Replace $this

$CI =& get_instance (); $CI->load->helper (' url '); $CI->load->library (' Session '); $CI->config-> Item (' Base_url ');//etc.

Annotations:

You will see that the get_instance () function above is passed by reference:

$CI =& get_instance ();

It is very important that the reference assignment allows you to use the original CodeIgniter object instead of creating a copy.

If the class library is a class, then we'd better use the OOP principle, so, in order for all methods in the class to use the CodeIgniter Super object, it is recommended to assign it to a property:

Class Example_library {    protected $CI;    We'll use a constructor, as can ' t directly call a function    //from a property definition.    Public function __construct ()    {        //Assign the CodeIgniter super-object        $this->ci =& get_instance ();    }    Public Function foo ()    {        $this->ci->load->helper (' url ');        redirect ();    }    Public Function bar ()    {        echo $this->ci->config->item (' Base_url ');}    }