Extending and extended class in CodeIgniter 3

Question

I have a controller "MY_Controller.php" in "application/core" that extends "CI_Controller":

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class MY_Controller extends CI_Controller
{

    function __construct()
    {
        parent::__construct();

        $this->load->helper('form');
        $this->load->helper('url');
        $this->load->helper('security');
        $this->load->helper('language');

        // Load language file
        $this->lang->load('en_admin', 'english');

    }

}

I created another controller called "Auth.php" in "application/controllers" that extends "MY_Controller":

class Auth extends MY_Controller
{

    function __construct()
    {
        parent::__construct();

        $this->load->library('ion_auth');

        if ($this->ion_auth->logged_in() === FALSE) {

            redirect('user/login');

        }
    }
}

I created a third controller "Dashboard.php" that should extend "Auth", but throws an error:

class Dashboard extends Auth
{
    public function index()
    {
        echo 'Hello from the dashboard';
    }
}

Fatal error: Class 'Auth' not found in /home/user/www/forum/application/controllers/Dashboard.php on line 5

Would appreciate your advice to solve this problem.

Try adding the Auth controller to the controllers auto load. I think the issue you're having is that CodeIgniter expects the class to be loaded so it knows about it — gabe3886
It has to do with the way CI looks for controllers. It leads to problems with extending them beyond the first MY_Controller. Multiple solutions can be found here. — DFriend

DFriend DFriend · Accepted Answer · 2016-10-28T22:11:51

The link in my comment has multiple ways to solve your problem. I prefer to use the #3 method - "Using an autoload function with hooks". Here's what works for me.

application/config/config.php

$config['enable_hooks'] = TRUE;

application/config/hooks.php

$hook['pre_system'][] = array(
  'class' => '',
  'function' => 'register_autoloader',
  'filename' => 'Auto_load.php',
  'filepath' => 'hooks'
);

application/hooks/Auto_load.php

<?php
    defined('BASEPATH') OR exit('No direct script access allowed');

    function register_autoloader()
    {
      spl_autoload_register('site_autoloader');
    }

    /*
     * Custom autoloader.
     * This piece of code will allow controllers and other classes 
     * that do not start with "CI_" to be loaded when  
     * extending controllers, models, and libraries.
     */
    function site_autoloader($class)
    {
        if(strpos($class, 'CI_') !== 0)
        {
            if(file_exists($file = APPPATH.'core/'.$class.'.php'))
            {
                require_once $file;
            }
            elseif(file_exists($file = APPPATH.'libraries/'.$class.'.php'))
            {
                require_once $file;
            }
            elseif(file_exists($file = APPPATH.'models/'.$class.'.php'))
            {
                require_once $file;
            }
        }
    }

Your first extend of CI_Controller - class MY_Controller extends CI_Controller - should probably be in application/core/MY_Controller.php. Any classes that extend MY_Controller should be in application/libraries/.

The linked page labels the "hook" method as "the slow and right way" but the profiling I did comparing it to "2. Using an autoload function (the fast and dirty way)" showed a time difference of slightly over a microsecond. That's not worth worrying about.

I used the "fast and dirty way" for many years but kept forgetting about it when upgrading CI and I'd overwrite the config file resulting in a lost autoloader routine. Don't have that problem using the hook method other than remembering to set $config['enable_hooks'] to TRUE.

Extending and extended class in CodeIgniter 3

3 Answers