The document discusses best practices for WordPress plugin development. It recommends starting with documentation, pairing with others during development, turning on debugging, using standard WordPress hooks and APIs, validating input for security, publishing plugins to the WordPress repository, and keeping plugins updated for new WordPress versions. The goal is to build well-designed, secure plugins that integrate smoothly with WordPress.

1. WordPress Plugin Development
WordCamp NL
03/24/2012

2. Luc De Brouwer
Webdeveloper who loves WordPress, Magento,
PHP, MySQL, HTML, CSS, jQuery, good food and
Nine Inch Nails.
• lucdebrouwer.nl
• hello@lucdebrouwer.nl
• linkedin.com/in/lucdebrouwer
• twitter.com/ldebrouwer

4. Developing for WordPress is awesome!

6. The basics

7. Always start with the read me /
documentation!

8. Pair with others
( Designers, developers, translators, ux specialists, etc. )

9. Turn debugging on
Your users will thank you for it.
Tip: Use Debug Bar and Debug Bar Console. It’s like Firebug for WordPress!

10. The nitty-gritty
a.k.a. the fun stuff

11. Standard plugin information

12. Time to get hooked!

13. Set some actions

14. Possible hooks
Filter functions Action functions
has_filter() has_action()
add_filter() add_action()
apply_filters() do_action()
current_filter() do_action_ref_array()
merge_filters() did_action()
remove_filter() remove_action()
remove_all_filters() remove_all_actions()

15. And some more..
Hooks for installation, activation, deactivation etc.

16. Set up your functions

17. Magic!

18. Do not reinvent the wheel!
WordPress has an API for almost anything. Built-in will most likely run better than bolted-on.

19. Storing preferences
You’ve got plenty of options!
add_option( ‘WordCampNL’, ‘FTW’ );
get_option( ‘WordCampNL’);
update_option( ‘WordCampNL’, ’#WCNL12 is awesome’ );

20. But of course you can use
custom tables tables too!

21. There’s an API for that!
Making HTTP requests, performing filesystem tasks, unzipping files, etc..

22. Namespace your stuff to avoid f*ck ups

23. Give your classes and functions a clear prefix

24. Security!
Validate input, check user rights. We don’t any CSRF, XSS attacks etc.

25. The Codex is your friend
http://codex.wordpress.org/

26. Publish your plugin to the
WordPress plugin repository
Free feedback and a bigger platform for your work!

27. Afterwards

28. Set up a support plan!
Will you give support? If so, when? Will you offer paid support?

29. Keep everything up-to-date
Check if it works with every WordPress update etc.

30. Embrace forks and feedback
Open source matters!

31. Consult the code
By reading the core I learned more in 2 hours then I could have learned in a 2 day course.

32. Thank you for your attention!

33. Questions?

34. Want to contact me or ask questions?
• lucdebrouwer.nl
• hello@lucdebrouwer.nl
• linkedin.com/in/lucdebrouwer
• twitter.com/ldebrouwer