CodeIgniter login across all pages

Question

I'm am very new to CI the MVC model.

I have a simple page which is made of up 3 views. Header, Content and Footer. The content will be unique across the site but header and footer will be the same, no matter what page.

In my header I have a login form. So there will be a login form across the whole site. since it appears on every page which has diff models:

how will or where will I write the script for logging in a user as I don't fancy writing a login script on every model the header is used on...

Maybe another example:

If that's not clear, I try another example. Suppose I have a site. In that I load a view which is a footer in all my pages. and the footer contains a form. Now when I post data using that form, where should that data it go?

Show it go to a dedicated PHP file which handles all the posts from that form, or should it go to the current page' controller?

I hope I was clear. Again I Just started using CI and MVC a day ago. It would be nice if you could guide me.

Answer 1

When i post data using that form, where should that data it go?

You shouldn't write the logic on every page (controller). What you should do is creating a distinct controller (like Accounts) for managing user logging.

The login form should post the data to accounts/login URL. but to get back to the previous page, we should store current URL in session as referer.

To do that, just store uri_string(); in the session on each page you need.

$this->session->set_userdata(array(
    'referer' => $this->uri->uri_string()
));

If you don't need to redirect the user to the previous page, ignore it.

The example below indicates how to achieve the goal:

class Accounts extends CI_Controller {

    public function login()
    {
        $config = array(
            // Write your validation rules here
        );

        $this->load->library('form_validation');
        $this->form_validation->set_rules($config);

        // Check whether form is submitted
        if (isset($_POST['submit'])) {

            if ($this->form_validation->run() == FALSE) {
                $data['login_errors'] = validation_errors();
                // Store validation errors in session
                // to display on every page needed
                $this->session->set_userdata($data);
            } else {

                // Login process
                // Set user detail in session

                // Redirect to previous page after login
                if ($referer = $this->session->userdata('referer')) {
                    $this->session->unset_userdata('referer');
                } else {
                    $referer='';
                }

                redirect(base_url().$referer);  
            }

        }
    }

    public function logout()
    {
        // Destroy the session
        $this->session->sess_destroy();
        redirect(base_url());
    }
}