Creating and managing Controllers

1. Create a New Controller:

1. Navigate to the application/controllers directory in your CodeIgniter project.
2. Create a new PHP file for your controller. The file name should match the controller class name.
3. Define your controller class, which should extend CI_Controller.
4. Implement methods within the controller class to handle different actions or pages in your application.

Example:

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

class Welcome extends CI_Controller {

    public function index() {
        // Controller method logic for the index page
    }

    public function about() {
        // Controller method logic for the about page
    }

    // Add more methods as needed
}
?>

2. Routing Requests to Controllers:

• By default, CodeIgniter routes requests to controllers based on the URI segment after the base URL.
• For example, if your base URL is http://localhost/myapp/, a request to http://localhost/myapp/welcome/about will route to the about() method in the Welcome controller.
• You can customize routing in the application/config/routes.php file if needed.

3. Loading Models and Views:

• Within your controller methods, you can load models and views as needed to interact with the database and render HTML output.
• Use $this->load->model() to load models and $this->load->view() to load views.
• Pass data to views using the second parameter of the load->view() method as an associative array.

Example:

<?
public function index() {
    // Load model
    $this->load->model('welcome_model');
    
    // Call model method to retrieve data
    $data['message'] = $this->welcome_model->get_message();
    
    // Load view with data
    $this->load->view('welcome_message', $data);
}
?>

4. Managing Controllers:

• Organize your controllers logically based on the functionality they provide.
• Avoid creating overly large controllers by separating related functionality into different controllers.
• Reuse code by creating base controllers or using CodeIgniter's modular structure.
• Ensure proper access control and security measures within your controllers to protect sensitive data and prevent unauthorized access.

5. Testing:

• Test your controllers by accessing the corresponding URLs in your browser or through API clients like Postman.
• Verify that the expected data is retrieved from models and passed to views correctly.
• Debug any errors or issues encountered during testing and refine your controller logic as needed.