How can I use proper object-oriented models in CodeIgniter with constructors?

Question

The way I create CodeIgniter models at the moment is (i.e. no constructor, having to pass userID all the time and limited to one object):

$this->load->model('User');
$this->user->set_password($userID, $password);

But I would like to do it like this:

$this->load->model('User');
$User = new User($userID);
$User->set_password($password);

UPDATE: Perhaps just a user model was a poor example.

For instance, if I have a shopping list that has various items I would like to use PHP in this way:

$this->load->model('List');
$this->load->model('Item');

$List = new List();
$items[] = new Item($itemName1, $itemPrice1);
$items[] = new Item($itemName2, $itemPrice2);

$List->add_items($items);

CodeIgniter feels fundamentally broken in handling PHP OO in this way. Does anyone have any solutions that can still use the superobject within every model?

Answer 1

You can do it like you normally would:

require_once(APPPATH.'models/User.php');
$User = new User($userID);

Or, you can rely on a table-level model to return a record-level model:

$this->load->model('users_model'); // users (plural) is the table-level model
$User = $this->users_model->get_user($userID);

Meanwhile, in users_model

require_once(APPPATH.'models/User.php');

public function get_user($userID)
{
  // get a record from the db
  // map record to model
  // return model
}