Codeigniter & HMVC Callback shows first - codeigniter

Question

On my codeigniter Version 3.1.4 / hmvc login if the form validation password input is empty for some reason the callback function shows first rather than the required message?
https://bitbucket.org/wiredesignz/codeigniter-modular-extensions-hmvc
As shown on message it should show the password required message first rather than callback
Question how can I make sure it shows the correct validation messages
first.
Autoloaded form_validation
$autoload['libraries'] = array('database', 'form_validation');
Controller
<?php
class Login extends MX_Controller {
public $CI;
public function __construct() {
parent::__construct();
$this->load->model('catalog/user/user_model');
$this->form_validation->CI =& $this;
}
public function index() {
$data['type'] = $this->input->post('type');
$data['password'] = $this->input->post('password');
$this->form_validation->set_rules('type', 'Username Or Email', 'trim|required');
$this->form_validation->set_rules('password', 'password', 'required|callback_validatePassword[password]');
if ($this->form_validation->run() == false) {
$data['header'] = Modules::run('catalog/common/header/index');
$data['footer'] = Modules::run('catalog/common/footer/index');
$this->load->view('template/account/login', $data);
} else {
$user_info = $this->user_model->get_user($user_id = '', $this->input->post('type', true));
if ($user_info) {
$remember = $this->input->post('remember') ? TRUE : FALSE;
$this->user->login($user_info['user_id'], $remember);
redirect(base_url("users") .'/'. $user_info['user_id'] .'/'. $user_info['username']);
}
}
}
public function validatePassword($str) {
if ($this->user_model->validate_password($str, $this->input->post('type', true))) {
return TRUE;
} else {
$this->form_validation->set_message('validatePassword', 'Opp\'s somthing wrong with login!');
return FALSE;
}
}
}
application > libraries > MY_Form_validation.php
<?php
class MY_Form_validation extends CI_Form_validation {
public $CI;
}

Answer 1

Instead of this -
$this->form_validation->set_rules('password', 'password', 'required|callback_validatePassword[password]');
kindly use the callback function like this -
$this->form_validation->set_rules('password', 'password', 'required', 'callback_validatePassword');

Answer 2

just keep the callback validation separate
$this->form_validation->set_rules('password', 'password', 'trim|required');
// check for post values is empty or not?
if(!empty($data['password'])) {
$this->form_validation->set_rules('password', 'password', 'callback_validatePassword[password]');
}