Upgrade Models¶

Documentation¶

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 have been added to CodeIgniter 4, the models must be changed to support namespaces.

Upgrade Guide¶

First, move all model files to the folder app/Models.
Add this line just after the opening php tag: namespace App\Models;.
Below the namespace App\Models; line add this line: use CodeIgniter\Model;.
Replace extends CI_Model with extends Model.
Add the protected $table property and set the table name.
Add the protected $allowedFields property and set the array of field names to allow to insert/update.
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 accordingly. For example, if 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 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 on those methods in Using CodeIgniter's Model.

Code Example¶

CodeIgniter Version 3.x¶

Path: application/models:

<?php

class News_model extends CI_Model
{
    public function set_news($title, $slug, $text)
    {
        $data = array(
            'title' => $title,
            'slug'  => $slug,
            'text'  => $text,
        );

        return $this->db->insert('news', $data);
    }
}

CodeIgniter Version 4.x¶

Path: app/Models:

<?php

namespace App\Models;

use CodeIgniter\Model;

class NewsModel extends Model
{
    // Sets the table name.
    protected $table = 'news';

    public function setNews($title, $slug, $text)
    {
        $data = [
            'title' => $title,
            'slug'  => $slug,
            'text'  => $text,
        ];

        // Gets the Query Builder for the table, and calls `insert()`.
        return $this->builder()->insert($data);
    }
}

The above code is a direct translation from CI3 to CI4. It uses Query Builder directly in the model. Note that when you use Query Builder directly, you cannot use features in CodeIgniter's Model.

If you want to use CodeIgniter's Model features, the code will be:

<?php

namespace App\Models;

use CodeIgniter\Model;

class NewsModel extends Model
{
    // Sets the table name.
    protected $table = 'news';

    // Sets the field names to allow to insert/update.
    protected $allowedFields = ['title', 'slug', 'text'];

    public function setNews($title, $slug, $text)
    {
        $data = [
            'title' => $title,
            'slug'  => $slug,
            'text'  => $text,
        ];

        // Uses Model's`insert()` method.
        return $this->insert($data);
    }
}