Writing web applications with CodeIgniter – Part 2

Last week, we covered the basic structure of a CodeIgniter application. Let’s now jump right into developing a simple todo list application using CodeIgniter. We will be keeping the actual functionality of the application itself simple here, as the goal here is to give a good overview on what it takes to build a CI application from scratch.

Okay, the first thing you have to do is to download and extract the latest build of CodeIgniter. Next, download the controllers, models and views that I have used in this sample todo list application. You should refer to these files as you read the tutorial. Here is the demo of the sample application (use “demo” as username and password).

Directory structure

All the files related to our application will be placed in the "system/application" folder:

As you can see, we have to place our controllers, views and models in their correspondng /controllers, /views and /models directories. Initially, we will have a sample controller (Welcome) in the /controllers directory, and its corresponding Welcome view in the /views directory. The model directory will be empty.

The /config directory consists of various files which will help us…