accessibilty issue with codeigniter session library

Question

I'm working on user login system in codeigniter. When user clicks on login button the username and password are verified and the data is store in $this->session->set_userdata($arr); session library and the page redirects to home.php. Till here works fine but when is try to access the session in home.php as print_r($this->session->userdata);. it give me this errors

Here is the Controller code : Login.php

function login_user(){
    $login_btn = $this->input->post('login_btn');

    if($login_btn == TRUE){
        $arr['login'] = array(
            'username'=>$this->input->post('username'),
            'password'=>$this->input->post('password')
        );

        $query = $this->Login_model->users_login($arr);

        if($query->num_rows() > 0 && $query->num_rows() == 1){
            $this->load->library('session');
            $this->session->set_userdata($arr);
            redirect('Login/redirec_To_home','refresh');    
        }
        else
        {
            $this->index();
        }
    }
    else
    {
        $this->index();
    }
}

function redirec_To_home(){
    $this->load->view('login/home');
}

Here is the view html file name : path views/login/home.php

<?php
    print_r($this->session->userdata); //ERRORS SHOWN IN THIS LINE NUMBER : 13
?>

THANKS IN ADVANCE

Answer 1

Please go to application/config/autoload.php in your project directory and search libraries, after that add session to this line which will look like this.

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

Answer 2

In the __construct area you need to reload the session library using get instance in libraries

https://www.codeigniter.com/user_guide/general/ancillary_classes.html

https://www.codeigniter.com/user_guide/general/creating_libraries.html#utilizing-codeigniter-resources-within-your-library

class Example {

    protected $CI;

    // We'll use a constructor, as you can't directly call a function
    // from a property definition.
    public function __construct()
    {
            // Assign the CodeIgniter super-object
            $this->CI =& get_instance();
            $this->CI->load->library('session');
            $this->CI->load->model('login_model');
    }

    public function somefunction()
    {
         $this->CI->input->post('username');
         $this->CI->input->post('password');

         $user_model = $this->CI->login_model->user_login();

         $sesstion_data = array('user_id' => '1');

         $this->CI->session->set_userdata($sesstion_data);
    }
}