Top 10 CodeIgniter interview questions with answer part -4

How do you handle database transactions in CodeIgniter?

Database transactions in CodeIgniter are handled using the $this->db->trans_start() and $this->db->trans_complete() methods. You can wrap database operations within these methods to ensure they are executed atomically. Here's an example:

$this->db->trans_start();
// Perform database operations
$this->db->trans_complete();

Explain how to implement internationalization (i18n) and localization (l10n) in CodeIgniter.

Internationalization (i18n) and localization (l10n) in CodeIgniter can be implemented using language files and the Language class. You can create language files for different languages and load them based on the user's locale. Here's an example:

$this->lang->load('filename', 'language');
echo $this->lang->line('key');

What are hooks in CodeIgniter, and how do you use them?

Hooks in CodeIgniter allow you to execute custom code at specific points during the request lifecycle. You can use hooks to modify the behavior of CodeIgniter without modifying its core files. Hooks are defined in the hooks.php file located in the config directory.

Explain the role of routes in CodeIgniter.

Routes in CodeIgniter allow you to map URLs to controller methods. You can define custom routes in the routes.php file located in the config directory. Routes provide a way to create user-friendly URLs and customize the routing structure of your application.

How do you implement authentication and authorization in CodeIgniter?

Authentication and authorization in CodeIgniter can be implemented using libraries like Ion Auth or by writing custom authentication logic. Libraries like Ion Auth provide pre-built authentication functionality, including user registration, login, logout, and password reset.

Explain the purpose of the config.php file in CodeIgniter.

The config.php file in CodeIgniter contains configuration settings for various aspects of the application, such as base URL, index page, session settings, and error handling. You can customize these settings to fit the requirements of your application.

How do you implement role-based access control (RBAC) in CodeIgniter?

Role-based access control (RBAC) in CodeIgniter can be implemented by associating users with roles and defining permissions for each role. You can create middleware or helper functions to check if a user has the required permissions to access certain resources.

Explain the purpose of the autoload.php file in CodeIgniter.

The autoload.php file in CodeIgniter allows you to specify which libraries, helpers, models, and other resources should be loaded automatically when the application starts. You can add or remove items from the autoload array to control what gets loaded.

How do you implement RESTful APIs in CodeIgniter?

RESTful APIs in CodeIgniter can be implemented using the REST_Controller library. You can create controller methods to handle different HTTP methods (GET, POST, PUT, DELETE) and return JSON or XML responses. The REST_Controller library provides helper methods for parsing request data and formatting responses.

Explain the purpose of the routes.php file in CodeIgniter.

The routes.php file in CodeIgniter allows you to define custom URL routes for your application. You can map URLs to controller methods, specify default controllers, and create custom routes for different URI patterns. Routes provide flexibility in defining the routing structure of your application.