Upgrade Sessions

Documentation

• Session Library Documentation CodeIgniter 3.x
• Session Library Documentation CodeIgniter 4.x

What has been changed

• Only small things like the method names and the loading of the library have changed.
• The definition of the session table in Database Driver has changed.

Upgrade Guide

1. Wherever you use the Session Library, replace $this->load->library('session'); with $session = session();.
2. From then on, you have to replace $this->session with $session, followed by the new method name, in every line starting with it.
   • To access session data, use the syntax $session->item or $session->get('item') instead of the CI3 syntax $this->session->name.
   • To set data, use $session->set($array); instead of $this->session->set_userdata($array);.
   • To remove data, use unset($_SESSION['some_name']); or $session->remove('some_name'); instead of $this->session->unset_userdata('some_name');.
   • To mark session data as flashdata, which will only be available for the next request, use $session->markAsFlashdata('item'); instead of $this->session->mark_as_flash('item');
3. If you use Database Driver, you need to recreate the session table. See DatabaseHandler Driver.

Code Example

CodeIgniter Version 3.x

<?php

$this->load->library('session');

$_SESSION['item'];
$this->session->item;
$this->session->userdata('item');

CodeIgniter Version 4.x

<?php

$session = session();

$_SESSION['item'];  // But we do not recommend to use superglobal directly.
$session->get('item');
$session->item;
session('item');