How do I load a session in Codeigniter 4 Constructor

Question

Just like in Codeigniter 3 where I can restrict users from a particular Controller if not on session by setting the below code in the Constructor

if(! session()->get('username'))
    {
        return redirect()->to('/login');
    }

When I try the same in Codeigniter 4 it will not work, until I load this in each method before it works

Answer 1

You need to initialize your session before calling session()->get('yourvar').
This should work :

$session = session();
$session()->get('username');

However, as your post says, if you need to check on every Controller if they're in need of a session or not, you should definitely give a look at Filters and create a custom one that check if there's a session or not. https://codeigniter.com/user_guide/incoming/filters.html

It would probably look like this in app/Filters :

<?php

namespace App\Filters;

use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\ResponseInterface;
use CodeIgniter\Filters\FilterInterface;

class LoginFilter implements FilterInterface {

    public function before(RequestInterface $request) {
        $session = session();
        if($session->has('username')) {
            return redirect()->to('/login'); 
        }
    }
    //--------------------------------------------------------------------

    public function after(RequestInterface $request, ResponseInterface $response) {
        // Do something here
        }

}

And if you want to implement a filter, don't forget to declare it in Config/Filters.php

// Makes reading things below nicer,
    // and simpler to change out script that's used.
    public $aliases = [
        'csrf'       => \CodeIgniter\Filters\CSRF::class,
        'toolbar'    => \CodeIgniter\Filters\DebugToolbar::class,
        'honeypot'   => \CodeIgniter\Filters\Honeypot::class,
        'login'      => \App\Filters\LoginFilter::class,
    ];

    // Always applied before every request
    public $globals = [
        'before' => [
            'login',
            //'honeypot'
        ],
        'after'  => [
            'toolbar',
            //'honeypot'
        ],
    ];