Using session data within a model

Since you have the $session object in your controller you could also pass it to the model when the model is constructed.

Passing objects to a class constructor as a way of supplying the object's dependencies is a very good habit to have. It's actually considered a best practice, especially if you're going to do unit testing of a class - and you really, really should unit test. Then passing dependencies to an object is pretty much a must.

So, one approach is to define a model like this.

PHP Code:

<?php namespace App\Models;

use CodeIgniter\Database\ConnectionInterface;
use CodeIgniter\Session\SessionInterface;

class UserModel
{
    protected $db;
    protected $session;

    public function __construct(ConnectionInterface &$db, SessionInterface &$session)
    {
        $this->db =& $db;
        $this->session =& $session; 
    }
} 


Use the model like this in a controller

PHP Code:

// other controller code

$session = Services::session();
$db = \Config\Database::connect();

$users = new UserModel($db, $session);

// other code 


If your model is extending /CodeIgniter/Model then there are a few minor changes, but I bet you get the idea.

Hi Dave, final question (honestly!)

I've taken your route and am injecting the database and session object references into the model constructor, as you have shown. I am extending the the COdeIgniter model and consequently, my database methods are now failing quietly. Obviously I'm missing a crucial step.

At the moment I'm following the CI4 tutorial from the official documentation, so for example, there is a method 'getNews'  which returns all rows in a db table with $this->findAll().

This is failing. I have also tried $this->db->findAll() with similar results.

Any advice is much appreciated.

Replying to my own post! I've finally fixed this. I realised that in my constructor method I also needed to place a call to the parent constructor method. All working now!