CodeIgniter Basic Introduction With Important Features 2022

CodeIgniter Basic Introduction

What is CodeIgniter?

For building a web application you spend tons of your time writing an equivalent code again and again. Frameworks provide you with a block and minimize the number of codes needed to create a website.

CodeIgniter is an open-source web framework for PHP. It is an Open Source framework, licensed under MIT License and its source code is maintained at GitHub. It has a really rich set of functionality, which can increase the speed of website development work.

If you are well familiar with PHP, then CodeIgniter will make your task easier. It’s a very rich set of libraries and helpers. By using CodeIgniter, you’ll save tons of your time, if you’re developing a website from scratch. Not only that, a website inbuilt CodeIgniter is secure too because it has the power to stop various attacks that happen through websites.


There is a large demand for the CodeIgniter framework among PHP developers because of its versatile features and advantages. A web application developed on CodeIgniter performs productively and quickly. It provides a sophisticated set of aspects to write down from scratch to create a dynamic web application.


Important Features

  • Free to use

It is licensed under the MIT license, so it’s liberal to use.

  • Follows MVC Pattern

It uses Model-View-Controller architectural design which basically separates logic and presentation parts. The request involves the controller, database action is performed through the model, and output is displayed through views.

But in PHP scripting, every page represents MVC which increases complexity.

  • Lightweight

It is extremely light-weighted. CodeIgniter core system requires a very small library and other libraries could also be added upon dynamic request based on your needs. That’s why it’s quite fast and lightweight weighted.

  • Generate SEO friendly URLs

URLs generated by CodeIgniter are search-engine friendly and very clean. It uses a segment-based approach instead of a standard query-based approach.

  • Built-in libraries

It comes with full packet libraries that enable all the online needed tasks like database, form validation, sending email, manipulating images, sending emails, etc.

  • Blazing fast

Users tend to favor applications that load in no time. If you’ve got worked with a number of the fashionable frameworks, then you’ll realize that they take less than one second to load just after installation. CodeIgniter, you’ll load on average around less than 50ms. The additional time spent optimizing is that the case in another framework is freed up once you are working with the CodeIgniter framework.

  • Loosely coupled

The built-in features are designed to work independently without relying an excessive amount on other components. This makes it easy to take care of and make better.

  • Excellent documentation

The framework is well documented, and there are good books, tutorials, and answer forum questions on CodeIgniter. This suggests whatever challenge that you simply have, chances are someone has already encountered the matter, solved it and therefore the solution is out there for you.

  • Extendable

It comes with some libraries and helpers out of the box. If what you want is not there otherwise you would like to implement an existing feature your way. Then you’ll be able to do so easily by creating your libraries, helpers, packages, etc. you’ll also create REST API in CodeIgniter.

  • Short learning curve

CodeIgniter is straightforward to master for anyone who is already familiar with PHP. Within a very short time, the scholar can learn it and begin developing professional applications using it.

Some other Features

    • Security and XSS Filtering
    • File uploading, session management, pagination, data enciphering
    • Flexible URI Routing
    • Zip encoding class
    • Error logging
    • Full-page caching
    • Localization

CodeIgniter Architecture

CodeIgniter is created to deliver maximum performance in less time within a clean environment. To achieve this, each developing process is created in a very simplified way.

From the technical point of view, it’s dynamically instantiation (libraries are loaded for the asking which makes it light-weighted), loose coupling. (Components rely very less on each other) and component singularity (each class and its functions are closely focused only on their purpose).


In the above snapshot, this flow chart displays data flow in CodeIgniter.

      • File index.php is the default file of CodeIgniter. It initializes the base resources.
      • The Router decides what should be done with the knowledge.
      • If a requested cache file exists, then the knowledge is passed directly to the browser ignoring the further processes.
      • Before loading Application Controller, the HTTP request and submitted data are passed under the Security check.
      • The application Controller loads Models, Libraries, Helpers, Plugins, and Scripts needed consistent with the request.
      • The final page will come to view and then be sent to the web browser. If the View page isn’t cached then it’ll be cached first for future requests.

Who is CodeIgniter For?

CodeIgniter is true for you if:

    1. You need a framework with a little footprint.
    2. You need exceptional performance.
    3. You need broad compatibility with standard hosting accounts that run a spread of PHP versions and configurations.
    4. You need a framework that needs nearly zero configuration.
    5. You need a framework that does not require you to use the instruction.
    6. You need a framework that does not require you to stick to restrictive coding rules.
    7. You aren’t curious about large-scale monolithic libraries like PEAR.
    8. You don’t want to be forced to find out a templating language (although a template parser is optionally available if you desire one).
    9. You eschew complexity, favoring simple solutions.
    10. You need clear, thorough documentation.

Following are the top 5 Websites using CodeIgniter in India

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  • CodeIgniter is a PHP framework for developing applications quickly
  • The entire source code for CodeIgniter is near to This makes it easy to master CodeIgniter and therefore the way it works
  • The built-in features of CodeIgniter are designed to figure independently without relying an excessive amount on other components
  • The framework uses the Model-View-Controller design architecture.
  • The framework is well documented, and they are good books, tutorials, and answer forum questions on CodeIgniter
  • It comes with some libraries, a simple interface, a logical structure, and helpers users of the box
  • CodeIgniter is simple to master for anyone who is already aware of PHP
  • In CodeIgniter user requests a resource and first, the controller gives the response. The controller understands the user request then requests the required data if it’s important
  • CodeIgniter version 4 was released On February 24, 2020, the birthday of Jim Parry, who was the project lead of CodeIgniter version 4 and died on January 15, 2020.