CodeIgniter 101 By: Chris Schmitz 

An open source PHP application framework Provides a lot of pre built functionality and conventions for code organization that let you focus on building out the logic for your applications. What is CodeIgniter? 

Why should I use it? ● Lightweight CodeIgniter: ~ 4MB CakePHP: ~ 7MB Zend: > 15MB Symfony: ~ 13MB 

Why should I use it? ● Lightweight ● Fast 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers ● SEO/User-friendly URLs 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers ● SEO/User-friendly URLs ● Flexible URI Routing 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers ● SEO/User-friendly URLs ● Flexible URI Routing ● A Command Line Interface (CLI) 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers ● SEO/User-friendly URLs ● Flexible URI Routing ● A Command Line Interface (CLI) ● Great documentation 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers ● SEO/User-friendly URLs ● Flexible URI Routing ● A Command Line Interface (CLI) ● Great documentation ● A very active/helpful community 

Why should I use it? ● Lightweight ● Fast ● Backwards compatible ● Infinitely extensible (Sparks) ● Comes with a lot of libraries and helpers ● SEO/User-friendly URLs ● Flexible URI Routing ● A Command Line Interface (CLI) ● Great documentation ● A very active/helpful community ● It is being actively developed 

What can it do? ● Libraries for almost anything you need to build web apps: ○ Database abstraction ○ Session management ○ Encryption ○ File uploads ○ Form validation ○ Shopping cart ○ Caching ○ Security ○ Benchmarking ○ and more! 

What can it do? ● Helpers to make your life easier: ○ Arrays ○ CAPTCHA ○ Cookie ○ Dates ○ Downloads ○ Email ○ Files ○ HTML ○ Language ○ Smilies ○ URL ○ and more! 

MVC ● Model: Represents your data structures. Handles interaction with the database. ● View: The information being presented to the user. ● Controller: An intermediary between the Model and the View, and any other resources needed to process the HTTP request. This provides a separation of concerns and gives you a logical place to put all of your code for different parts of your application. 

A Sample Request 

CodeIgniter associates URI strings with controller classes and methods. http://example.com/users/show/1 Gets routed to the show method of the users controller and passes a parameter with a value of 1 to the method. class Users extends CI_Controller { public function show($id) { // grab the user from the database or something... } } Routing 

Extensibility Sparks is a package management system just for CodeIgniter. Composer and Packagist are starting to pick up traction as a standardized way to share libraries across all PHP applications. In addition to integrating third-party code, you can also extend CI's core classes with ease. 

See it in action Live coding! 

The Future ● Test coverage ● Not a lot of new feature development ● Many long-time CI developers are changing frameworks The Bottom Line: It's a very dependable, backwards compatible, and easy to learn framework and is well-suited for lightweight web applications. However, if you want to play with the latest and greatest, there are other options you will probably be happier with. 

Self-Promotion Perm: A simple, flexible access control system Decorator: Allows you to create decorators (aka presenters) to prep data before returning it to the view These repos are pull request-friendly! 

Thanks! I'm Chris Schmitz. Hit me up on Twitter (@ccschmitz) with any CodeIgniter questions! Demo app can be fount on GitHub at: https: //github.com/foxcitiesphp/ci-demo-app