file login.php

<?php if(!defined('BASEPATH')) exit('Hacking Attempt : Keluar dari sistem..!!');
    class Login extends CI_Controller {

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

            $this->load->model('m_login');
            $this->load->library(array('form_validation','session'));
            $this->load->helper('url');

        }

        public function index() {
            $session = $this->session->userdata('isLogin');

            if($session == FALSE) {
                redirect('login/login_form');
            } else {
                redirect('home');
            }
        }

        public function login_form() {
            $this->form_validation->set_rules('username', 'username', 'required|trim|xss_clean');
            $this->form_validation->set_rules('password', 'Password', 'required|trim|xss_clean');
            $this->form_validation->set_error_delimiters('<span class="error">', '</span>');

            if($this->form_validation->run()==FALSE) {
                $this->load->view('form_login');
            } else {
                $username = $this->input->post('username');
                $password = $this->input->post('password');

                $cek = $this->m_login->ambilPengguna($username, $password, 1);

                if($cek->num_rows() <> 0) {
                    $this->session->set_userdata('isLogin', TRUE);
                    $this->session->set_userdata('data_user',$cek->row());

                    redirect('home');
                } else {
                    echo " <script>
                        alert('Gagal Login: Kombinasi Username Salah Atau Akun Belum Di Verifikasi!');
                        history.go(-1);
                        </script>";
                }
            }
        }

        public function logout() {
            $this->session->sess_destroy();

            redirect('login/login_form');
        }
    }
?>