CodeIgniter 2: How to extend CI_Controller multiple times?

Question

I have successfully extended the CI_Controller class by creating a MY_Controller.php which I have placed in the application/core directory.

core/My_Controlle

Answer 1

All files in the folder application/core

---

MY is subclass CI
MY have 2 subclasses Public and Dashboard

class MY_Controller extends CI_Controller
{
    public function __construct()
    {
        parent::__construct();

        echo "This is " . __CLASS__ . "
";
    }
}

Public

class Public_Controller extends My_Controller
{
    public function __construct()
    {
        parent::__construct();

        echo "This is " . __CLASS__ . "
";
    }
}

Dashboard have 2 subclasses, Admin and User

class Dashboard_Controller extends My_Controller
{
    public function __construct()
    {
        parent::__construct();

        echo "This is " . __CLASS__ . "
";
    }
}

Admin

class Admin_Controller extends Dashboard_Controller
{
    public function __construct()
    {
        parent::__construct();

        echo "This is " . __CLASS__ . "
";
    }
}

User

class User_Controller extends Dashboard_Controller
{
    public function __construct()
    {
        parent::__construct();

        echo "This is " . __CLASS__ . "
";
    }
}

in config/config.php

/* load class in core folder */
function my_load($class) {        
    if (strpos($class, 'CI_') !== 0) {            
        if (is_readable(APPPATH . 'core' . DIRECTORY_SEPARATOR . $class . '.php' )) {                
            require_once (APPPATH . 'core' . DIRECTORY_SEPARATOR . $class . '.php');                
        }
    }        
}

spl_autoload_register('my_load');

in controller/Home.php

//class Home extends MY_Controller {
//class Home extends Dashboard_Controller {
class Home extends Admin_Controller {

    public function index()
    {
        echo "This is " . __CLASS__ . "
";
        //$this->load->view('home');
    }
}