登录后单击“后退”按钮，将登录的用户重定向到主页

Question

I'm currently learning the basics of MVC using codeigniter as my framework and I created a login page. Now I already redirected a user after he logged in and stored a session data but the problem is after I log in (where in I redirected into another page) then pressed the back button the login page still displays unless I highlight the URL in the address bar and pressed enter wherein I go back again to the redirected page. Well I'm aware that this is because of the session check I've made but I need a solution on how I can solve it for the user to not go back again to login page unless he logged out. Same thing for logged out user not to go back to a certain page unless he/she logs in again.

To give a more details what exactly I wanted to happen is just like in facebook login wherein after you logged in and clicked the back button on browser the facebook will still redirect you to your homepage and not on the login page. samething goes to logout.

Well here's my controller so far I think this explains it all. Please do correct me if I made some redundancies in my code and understand that I'm a newbie on this. :)

public function index()
{
    $data['error'] = null;
    $username = $this->input->post('username');
    $password = $this->input->post('password');
    $data['login'] = $this->login_model->get_login_credentials($username,$password);
    $data['session'] = $this->login_model->get_session($username);


    //CHECK IF THE $PAGE VIEW IS EXISTING
    if ( ! file_exists('application/views/pages/login.php'))
    {
        // IF PAGE DOESN'T EXISTS SHOW 404 ERROR
        show_404();
    }

    if(($this->input->post('login')=='Login'&&$data['login']==1)||($username==$data['session']['username'])){
        //SUCCESS LOGIN
        $this->load->helper('url');  
        redirect('news');
    }

    if($this->input->post('login')=='Login'&&$data['login']!=1){
        //LOGIN FAILED
        $data['error'] = "Invalid login credentials.";
    }


    //FOR THE TITLE PART
    $data['title'] = ucfirst('login'); 

    $this->load->view('pages/login/login', $data);
    $this->load->view('templates/footer', $data);

}

Answer 1

First for checking session data you can use :

$this->session->userdata('item');

here

$username==$data['session']['username'])

And perhaps you can SET 1 check at the start of your index as :

if($this->session->userdata('username'))
redirect('news');

Dont forget to load all helpers and libs required before callign those functions..

For sessions check http://codeigniter.com/user_guide/libraries/sessions.html

Answer 2

If you don't want to to go to login page after successful login, you can test the session in login page and redirect into some other page if session is set. Try this code.

if ($data['session']['username']) != NULL) {
    redirect('home_page','refresh');
}

Answer 3

这个问题已经在这里解决： 按下后清除缓存，以防止 Hashem Qolami 注销后返回登录页面或上一页相同的问题，但观点不同。