codeigniter check for user session in every controller

Another option is to create a base controller. Place the function in the base controller and then inherit from this.

To achieve this in CodeIgniter, create a file called MY_Controller.php in the libraries folder of your application.

class MY_Controller extends Controller{    public function __construct()    {        parent::__construct();    }    public function is_logged_in()    {        $user = $this->session->userdata('user_data');        return isset($user);    }}

Then make your controller inherit from this base controller.

class X extends MY_Controller{    public function __construct()    {        parent::__construct();    }    public function do_something()    {        if ($this->is_logged_in())        {            // User is logged in.  Do something.        }    }}

Put it in a helper and autoload it.

helpers/login_helper.php:

function is_logged_in() {    // Get current CodeIgniter instance    $CI =& get_instance();    // We need to use $CI->session instead of $this->session    $user = $CI->session->userdata('user_data');    if (!isset($user)) { return false; } else { return true; }}

config/autoload.php:

$autoload['helper'] = array('login');

Then in your controller you can call:

is_logged_in();

You can achieve this using helper and CodeIgniter constructor.

1. You can create custom helper my_helper.php in that write your function

   function is_logged_in() {  $user = $this->session->userdata('user_data');  if (!isset($user)) {    return false;   }  else {    return true; }} 

2. In controller if its login.php

   class Login extends CI_Controller {    public function __construct()    {        parent::__construct();        if(!is_logged_in())  // if you add in constructor no need write each function in above controller.         {         //redirect you login view        }    }