Create & Extend Reusable Base Controller in CodeIgniter

In CodeIgniter, you can create a base controller and then extend it to other controllers as a Reusable Base Controller. This approach is useful for sharing common functionality, like loading models, setting common properties, or including utility methods.

Here’s how you can do it:

Step 1: Create the Base Controller

Create a new PHP file for your base controller in the application/core directory. Let’s name it MY_Controller.php.
Define the base controller class. This class should extend CI_Controller.

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class MY_Controller extends CI_Controller {

    public function __construct() {
        parent::__construct();
        // Load common models, libraries, helpers, etc.
        $this->load->model('User_model');
        // Additional common setup
    }

    // Add any common methods you want to use in all controllers
    protected function render($view, $data = array()) {
        $this->load->view('header', $data);
        $this->load->view($view, $data);
        $this->load->view('footer', $data);
    }
}

Step 2: Extend the Base Controller in Your Controllers

Modify your existing controllers to extend MY_Controller instead of CI_Controller.

User Controller Example

Create or modify the controller in the application/controllers directory. Let’s use User.php as an example.

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class User extends MY_Controller {

    public function __construct() {
        parent::__construct();
        // User-specific setup
    }

    public function show($id) {
        $data['user'] = $this->User_model->get_user_by_id($id);
        $this->render('user_view', $data);
    }

    public function index() {
        $data['users'] = $this->User_model->get_all_users();
        $this->render('users_view', $data);
    }
}

Step 3: Create Views (If Necessary)

Ensure your view files are set up correctly in the application/views directory.

Example View Files

user_view.php

<!DOCTYPE html>
<html>
<head>
    <title>User Details</title>
</head>
<body>
    <h1>User Details</h1>
    <?php if ($user): ?>
        <p>ID: <?php echo $user['id']; ?></p>
        <p>Name: <?php echo $user['name']; ?></p>
        <p>Email: <?php echo $user['email']; ?></p>
    <?php else: ?>
        <p>User not found.</p>
    <?php endif; ?>
</body>
</html>

users_view.php

<!DOCTYPE html>
<html>
<head>
    <title>All Users</title>
</head>
<body>
    <h1>All Users</h1>
    <?php if ($users): ?>
        <ul>
            <?php foreach ($users as $user): ?>
                <li><?php echo $user['name']; ?> (<?php echo $user['email']; ?>)</li>
            <?php endforeach; ?>
        </ul>
    <?php else: ?>
        <p>No users found.</p>
    <?php endif; ?>
</body>
</html>

header.php

<!DOCTYPE html>
<html>
<head>
    <title>My Application</title>
</head>
<body>

footer.php

</body>
</html>

Summary

Create a base controller (MY_Controller.php) in application/core.
Extend the base controller in your specific controllers (User.php).
Use common methods defined in the base controller in your specific controllers.

By following these steps, you can create a base controller in CodeIgniter and extend it in other controllers, allowing for code reuse and better organization of common functionality.

CodeIgniter Tech