Upgrade Models

Documentations

What has been changed

  • The CI4 model has much more functionality, including automatic database connection, basic CRUD, in-model validation, and automatic pagination.

  • Since namespaces has been added to CodeIgniter 4, the models must be changed to support namespaces.

Upgrade Guide

  1. First, move all model files to the folder app/Models.

  2. Add this line just after the opening php tag: namespace App\Models;.

  3. Below the namespace App\Models; line add this line: use CodeIgniter\Model;.

  4. Replace extends CI_Model with extends Model.

  5. Instead of CI3’s $this->load->model('x');, you would now use $this->x = new X();, following namespaced conventions for your component. Alternatively, you can use the model() function: $this->x = model('X');.

If you use sub-directories in your model structure you have to change the namespace according to that. Example: You have a version 3 model located in application/models/users/user_contact.php the namespace has to be namespace App\Models\Users; and the model path in the version 4 should look like this: app/Models/Users/UserContact.php

The new Model in CI4 has a lot of built-in methods. For example, the find($id) method. With this you can find data where the primary key is equal to $id. Inserting data is also easier than before. In CI4 there is an insert($data) method. You can optionally make use of all those built-in methods and migrate your code to the new methods.

You can find more information to those methods in Using CodeIgniter’s Model.

Code Example

CodeIgniter Version 3.x

Path: application/models:

<?php

class User_contact extends CI_Model
{
    public function insert($name, $address, $email)
    {
        $this->db->insert('user_contacts', array(
            'name'    => $name,
            'address' => $address,
            'email'   => $email,
        ));
    }
}

CodeIgniter Version 4.x

Path: app/Models:

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserContact extends Model
{
    // insert() method already implemented in parent
}

To insert data you can just directly call the $model->insert() method because this method is built-in since CI4.