A session by Eng.Ibrahim Abdel Fattah Mohamed in WordCamp Egypt 2009, discussing how you can start with coding your own WordPress Plugins.

1. Write your first WordPress Plugin
Ibrahim Abdel Fattah Mohamed, aka bingorabbit
www.bingorabbit.com
Twitter: @bingorabbit
.. and I HEART WordPress

2. Agenda
● What is a WordPress Plugin?
● Why do I need to write a WordPress Plugin?
● Plugin files structure and headers.
● How to add my plugin to my WordPress Blog.
● How to contribute to WordPress Development?
● Questions..

3. What is a WordPress Plugin?
A piece of code, written to solve a problem or to
add a specific functionality that is not there.

4. Why do I need to write a WordPress Plugin?
● Solving a problem.
● Add new functionality
● You love it, but have a better implementation?
● Modify it, extend it
● Want to make money?

5. How can I write a plugin?
● Find a problem you need to solve, or
something new to add.
● Warm your hands.
● Choose a descriptive name.
● Document every little thing.
● Think about the license.
● Then start coding it..

6. Structure
Wordpress/
|- wp-content/
|- plugins/
|- YourPlugin/
|- mainfile.php
|- js/
|- css/
|- php/

7. Headers
<?php
/*
Plugin Name: Your desired name
Plugin URI: http://path.to/plugin/
Description: What does it actually do?
Version: x.Y
Author: This should be you
Author URI: http://path.to/you/
*/
?>

8. Hooks
● Hooks are just..hooks..
● Used to attach your plugin to a working system.
● Two types of Hook; Actions and Filters

9. Actions
● Actions, are just actions..
● Actions triggers an event or a function.
● When a post is published (action), send an email
to the administrator (function, event or reaction).
add_action('hook_name',
'your_function_name', [priority],
[accepted_args]);

10. Filters
Database/User <----> Filters <----> Data
● Filters are also just..Filters..
● Example, add some text just after every post.
add_filter('hook_name',
'your_function_name', [priority],
[accepted_args]);

11. Sample Plugin:
Email Friends on New Post

12. Important Links
● Writing a Plugin (
http://codex.wordpress.org/Writing_a_Plugin)
● Plugin API (http://codex.wordpress.org/Plugin_API)
● Actions Reference (
http://codex.wordpress.org/Plugin_API/Action_Reference)
● Filters Reference (
http://codex.wordpress.org/Plugin_API/Filter_Reference)
● WordPress Coding Standards (
http://codex.wordpress.org/WordPress_Coding_Standards)

13. Contributing to WordPress..

14. Why?
● Improve the software you use..
● Being a part of the community, learning and
experience.

15. Where?
● Documentation, aka Codex (
http://codex.wordpress.org/Codex:Contributing)
● Translation (
http://codex.wordpress.org/Translating_WordPress)
● Support Forum (http://www.wordpress.org/support)
● IRC Channel (#WordPress-dev on Freenode)
● Development (Next Slide?)

16. How?
● Trac (http://trac.wordpress.org/)
● Code it, refine it, or just test it..
● Got a bug? Go and report it..
http://wordpress.org/development/2009/03/contributing-to-wordpress-part-i-development/

17. Any Questions?..

18. Thanks!..
Ibrahim Abdel Fattah Mohamed
www.bingorabbit.com
www.catreloaded.net