Course Content
Introduction to CodeIgniter
CodeIgniter is a powerful PHP framework built for developers who need a simple and elegant toolkit to create full-featured web applications.
MVC (Model-View-Controller)
MVC stands for Model-View-Controller. MVC is an application design model consisting of three interconnected parts. They include the model (data), the view (user interface), and the controller (processes that handle input).
The Session class allows you to maintain a user’s "state" and track their activity while they browse your site.
URI Routing
There is a one-to-one relationship between a URL string and its corresponding controller class/method. The segments in a URI normally follow this pattern:
Forms and Input
Forms provide a way for users to interact with the application and submit data.
Composer is dependency manager in PHP. it allows you to declare the libraries your project depends on and it will manage (install/update) them for you.
You can enable CSRF protection by modifying your application/config/config.php file
Working with Database
Like any other framework, we need to interact with the database very often and CodeIgniter makes this job easy for us. It provides a rich set of functionalities to interact with the database.
DataTables is a table enhancing plug-in for the jQuery Javascript library that helps in adding sorting, paging, and filtering abilities to plain HTML tables with minimal effort. The main goal is to enhance the accessibility of data in normal HTML tables.
PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Importing Excel and CSV into MySQL help to save the user time and avoid repetitive work.
Payment Gateway
Razorpay and PayTM Payment Gateway
WhatsApp Chatbot and Telegram Chatbot
CodeIgniter 3
About Lesson

A session is used to store information (in variables) and used throughout the application.

Session Initialization

To store data in session first of all we need to initialize the session.

In PHP we initialize the session by simply writing the session_start(); function.

But in CodeIgniter, We can do that by executing the following line in the constructor.


Add data to the session

set_userdata() method is used to add value to the session. It takes two arguments as a parameter first is session name and the second is session value.

$this->session->set_userdata(‘session name', ‘any_value’);

We can also use the set_userdata() function to pass an array to store values as shown below.

$data = array(
	'username' => 'junaidsshaikh',
	'email' => ‘',
	'logged_in' => TRUE

Remove data from Session

We can use unset_userdata() function that will remove data from the session.


If you want to remove more than one value and an array of data then you can use the same function unset_userdata().


Fetch data from Session

A userdata() function is used to get data from the session. It takes the session key name as an argument. For example:

$name = $this->session->userdata('name');


While building a web application, we need to store some data for only one time, and later, we want to remove that data. For example, to display some error message or information message. In CodeIgniter, flashdata will only be available until the next request, and it will get deleted automatically.

Add Flashdata


Retrieve a Flashdata