How to apply all session in all controller in codeigniter?

Question

I have problem when creation session
login to system done with no error and I can print session data but my problem is

First, when I move from page to page no session data found and I can open any function by writing URL of my protect without transferring me in login page

Second: I want to apply all session in all controller

This is my code: controller

class Users extends CI_Controller
{
    public function __construct()
    {
        parent::__construct();
        $this->load->library('session');
    //  print_r($this->session->userdata);

    }

    public function Login()
    {
        if($this->input->post("login"))
        {
            $this->load->library('form_validation');
            $this->form_validation->set_rules("username","UserName",'required|min_length[3]|max_length[30]|alpha');
            $this->form_validation->set_rules("password","password",'required|min_length[3]|max_length[30]');
            if ($this->form_validation->run())
            {
                $username=$this->input->post("username");
                $password=$this->input->post("password");
                $encpassword=md5($password);
                $this->load->model("DatabaseModel");

                if($info=$this->DatabaseModel->mainlogin($username,$encpassword))
                {
                    if(is_object($info)){

                            $session_data=array(
                                'username' => $info->username,
                                'id'       =>$info->id,
                                'email' => $info->email,
                                'image' => $info->image

                            );
                        $this->session->set_userdata($session_data);
                    }
                    $this->session->set_userdata($session_data);
                    redirect(site_url("Dashboard/index"));

                }else{
                    $this->session->set_flashdata('error', 'Error With Login ');
                    redirect(site_url("Users/login"));
                }

            }else{
                //error for validation
            }
        }

        $data['pagetitle']="IStore | Login";
        $this->load->view("users/login",$data);
        //$this->load->view("users/login");
    }

    public function logout()
    {
        $this->session->unset_userdata('username');
        $this->session->unset_userdata('id');
        $this->session->unset_userdata('email');
        $this->session->unset_userdata('image');
        redirect(site_url("Users/login"));
    }
}

This is my databasemodel

public function mainlogin($username,$password)
{
    $this->db->select('*');
    $this->db->from("users");
    $this->db->where('username',$username);
    $this->db->where('password',$password);
    $sql=$this->db->get();
    return $sql->row();
}

Answer 1

autoload.php

you should set your session library in autoload.php file of config folder

/*
| -------------------------------------------------------------------
|  Auto-load Libraries
| -------------------------------------------------------------------
| These are the classes located in the system/libraries folder
| or in your application/libraries folder.
|
| Prototype:
|
|   $autoload['libraries'] = array('database', 'session', 'xmlrpc');
*/


$autoload['libraries'] = array('session');

After set session in autoload.php you can get session data in all contoller ,and then you can check your session that this is destroy or not if your session has destroyed than you can redirect user from that page

This is answer to how prevent user to access pages without login

codeigniter check for user session in every controller

I hope this will help you