How to create custom helper in CodeIgniter

Last updated on November 18, 2022

In this tutorial, I would like to show creating a custom helper in your CodeIgniter application. Helper functions are used to avoid repeated code in your controllers and views, it encourages you to follow a good practice called DRY. You can call the helper methods in your views as well as in your controllers.

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Let’s see how we can create and use a custom helper in CodeIgniter.

Create Custom Helper

In application/helpers folder create a new PHP file app_helper.php.

if (! defined('BASEPATH')) exit('No direct script access allowed');

if (! function_exists('demo')) {
    function demo()
    {
        // get main CodeIgniter object
        $ci = get_instance();
       
        // Write your logic as per requirement
        
    }
}

NOTE: In helper functions, you can not use the $this keyword to access the CI’s object, so you have to call get_instance() function, this method will give access to the CI’s object. Using this object you load other helpers, libraries ..etc.

How to use the custom helper

You can load a custom helper in two ways, globally or within the controller, or within the controller method. Below are two approaches

How to load custom helper globally:
Open your application/config.php file and search for the helper array and add your custom helper name to the array.

/*
| -------------------------------------------------------------------
|  Auto-load Helper Files
| -------------------------------------------------------------------
| Prototype:
|
|	$autoload['helper'] = array('url', 'file');
*/
$autoload['helper'] = array('app');

How to load custom helper within the controller:
Just like any other build-in helpers, you can load your custom helper

//load custom helper 
$this->load->helper('app');

How to use the custom helper

After loading the helper with any of the above methods you can use the helper function in your controller and views.

// just call the function name
demo();