<?php
    require_once(FUEL_PATH.'/libraries/Fuel_base_controller.php');

    error_reporting(-1);
    ini_set('display_errors', 1);
    class Testas extends CI_controller {

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

        public function index()
        {
            $this->load->module_language('fuel', 'fuel');
            $this->load->library('form_builder');
            $this->load->library('validator');

            $fields['email'] = array('type' => 'email', 'label'=>'Email', 'required' => TRUE);
            $fields['name'] = array('type' => '','label'=>'Your name');
            $this->form_builder->set_fields($fields);

            $validator = $this->form_builder->get_validator();

            //var_dump($validator);exit; //If I uncomment it, it echoes NULL

            $validator->add_rule('name', 'required', "This is required", array($this->input->post('name')));

            if (!empty($_POST))
            {
                if ($validator->is_valid())
                {
                    echo "validation succeeded";

                }
                else
                {
                    echo "validation failed";
                }
            }
        }
    }