How to Build a Basic Web Application with CodeIgniter 3 - Web applications are becoming increasingly popular as businesses and individuals seek to leverage the power of the internet to reach their audiences. CodeIgniter 3 is a popular PHP framework that makes it easy for developers to build web applications quickly and efficiently. In this article, we will explore how to build a basic web application with CodeIgniter 3.

Table of Contents

1. Introduction
2. Getting Started with CodeIgniter 3
3. Setting up the Development Environment
4. Understanding CodeIgniter MVC Architecture
5. Creating the Basic Web Application Structure
6. Setting up the Database
7. Creating Models
8. Creating Views
9. Creating Controllers
10. Implementing CRUD Operations
11. Validating Forms
12. Creating User Authentication
13. Deploying the Web Application
14. Testing the Web Application
15. Conclusion

Introduction

CodeIgniter 3 is a lightweight PHP framework that follows the Model-View-Controller (MVC) architectural pattern. The framework provides developers with a set of tools and libraries that simplify the development process, allowing them to create web applications quickly and efficiently.

In this article, we will walk you through the process of building a basic web application using CodeIgniter 3. We will cover everything from setting up the development environment to deploying and testing the web application.

Getting Started with CodeIgniter 3

Before we start building our web application, we need to install CodeIgniter 3. You can download the framework from the official website (https://codeigniter.com/). Once you have downloaded the framework, extract the files and place them in your web server's document root.

Setting up the Development Environment

To set up the development environment, you will need a web server (such as Apache) and a database server (such as MySQL). You can install these on your local machine or use a remote server.

Understanding CodeIgniter MVC Architecture

CodeIgniter follows the Model-View-Controller (MVC) architectural pattern. This pattern separates the application into three parts: the Model (which handles data), the View (which handles presentation), and the Controller (which handles the user input).

Creating the Basic Web Application Structure

To create the basic web application structure, we need to create the following directories and files:

• application/controllers
• application/models
• application/views
• application/config/database.php
• index.php

The controllers directory will contain the PHP files that handle user input, the models directory will contain the PHP files that handle data, and the views directory will contain the HTML files that handle presentation.

Setting up the Database

To set up the database, we need to create a database and a table. You can use any database management tool (such as phpMyAdmin) to create the database and table. Once the database and table are created, we need to configure the database settings in the application/config/database.php file.

Creating Models

Models are PHP classes that handle data. In CodeIgniter, models are placed in the application/models directory. To create a model, we need to create a PHP file with a class that extends the CodeIgniter Model class.

Creating Views

Views are HTML files that handle presentation. In CodeIgniter, views are placed in the application/views directory. To create a view, we need to create an HTML file with the desired presentation.

Creating Controllers

Controllers are PHP classes that handle user input. In CodeIgniter, controllers are placed in the application/controllers directory. To create a controller, we need to create a PHP file with a class that extends the CodeIgniter Controller class.

Implementing CRUD Operations

CRUD stands for Create,

Update, and Delete. These are basic database operations that are required in almost every web application. To implement these operations, we need to create functions in our controller that interact with the database through our model.

Validating Forms

Forms are a crucial component of web applications. It is essential to validate user input to ensure that the data is correct and safe to use. CodeIgniter provides built-in form validation libraries that make it easy to validate user input.

Creating User Authentication

User authentication is another critical component of web applications. We need to ensure that only authorized users can access certain parts of the application. CodeIgniter provides built-in user authentication libraries that make it easy to implement user authentication.

Deploying the Web Application

Once our web application is complete, we need to deploy it to a web server. This involves transferring the files to the web server and configuring the server settings to run the application.

Testing the Web Application

Testing is a crucial part of the development process. We need to ensure that our web application works as expected and is free of bugs. CodeIgniter provides built-in testing libraries that make it easy to test our web application.

Conclusion

CodeIgniter 3 is a powerful PHP framework that makes it easy to build web applications quickly and efficiently. In this article, we covered the basics of building a web application with CodeIgniter 3, including setting up the development environment, creating the basic application structure, implementing CRUD operations, validating forms, creating user authentication, deploying the web application, and testing the web application.

FAQs

1. What is CodeIgniter 3? CodeIgniter 3 is a PHP framework that follows the Model-View-Controller (MVC) architectural pattern. The framework provides developers with a set of tools and libraries that simplify the development process, allowing them to create web applications quickly and efficiently.
2. What is MVC architecture? MVC stands for Model-View-Controller, which is a software architectural pattern for implementing user interfaces. It separates the application into three parts: the Model (which handles data), the View (which handles presentation), and the Controller (which handles the user input).
3. What is user authentication? User authentication is the process of verifying the identity of a user who is trying to access a web application. It ensures that only authorized users can access certain parts of the application.
4. How do I deploy a CodeIgniter 3 web application? To deploy a CodeIgniter 3 web application, you need to transfer the files to a web server and configure the server settings to run the application.
5. How do I test my CodeIgniter 3 web application? CodeIgniter provides built-in testing libraries that make it easy to test your web application. You can write test cases to ensure that your application works as expected and is free of bugs.