CodeIgniter 3 - Extending Form Validation not working

First, fix the constructor for MY_Form_validation:

PHP Code:

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

class MY_Form_validation extends CI_Form_validation 
{
    public function __construct($rules = array())
    {
        // Pass the $rules to the parent constructor.
        parent::__construct($rules);
        // $this->CI is assigned in the parent constructor, no need to do it here.
    }

    public function is_required($str)
    {
        if (empty($str))
        {
            $this->CI->form_validation->set_message('is_required', 'The %s is required');
            return FALSE;
        }

        return TRUE;
    }
} 


and the User controller:

PHP Code:

<?php
class User extends MY_Controller {

    public function __construct()
    {
        parent::__construct();
        // No need to use get_instance() in a controller 
        // which extends a child of CI_Controller.
    }

    public function login()
    {
        if ($this->input->post('submit'))
        {
            $this->form_validation->set_rules('username', 'Username', 'is_required');
            $this->form_validation->set_rules('password', 'Password', 'is_required');
            if ($this->form_validation->run() === FALSE)
            {
                echo " Failed <br/>";
            }
            else
            {
                echo " Success <br/>";
            }
        }
    }
} 


However, the problem may simply be in your is_required() method's logic, as empty() isn't necessarily going to give you the expected result. This is why CI's Form_validation->required() method looks like this:

PHP Code:

    public function required($str)
    {
        return is_array($str) ? (bool) count($str) : (trim($str) !== '');
    } 


Bonfire

Practical CodeIgniter 3
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