An Introduction to Plugin Development - WCBNE 19

Have you ever wanted to build your own plugin? Or maybe you’re just curious as to how plugins work? We’ll take a look at some popular plugins, learn the WordPress hook system, then walk through building your first custom WordPress plugin from scratch.

Transcript

1. An Introduction to Plugin Development Cameron Jones
2. @cameronjonesweb An Introduction to Plugin Development What We’re Gonna Build We will be building a plugin to customise the WordPress login screen with our own logo
3. @cameronjonesweb An Introduction to Plugin Development About Me Cameron Jones Freelance WordPress developer Founder of Mongoose Marketplace @cameronjonesweb on all the things • Made my first website in 2006 with Microsoft Publisher • Started programming in 2008 with Flash Actionscript 2.0 to make flash games • Fell in love with WordPress in 2014 • Released my first plugin on WordPress.org in 2015 • Released my first premium plugin in 2019
4. @cameronjonesweb An Introduction to Plugin Development What You Need To Know • What a plugin is • Where plugins are installed • A little bit of PHP
5. @cameronjonesweb An Introduction to Plugin Development What You Need To Build A Plugin • A local development environment • A text editor
6. @cameronjonesweb An Introduction to Plugin Development Local Development Environments
7. @cameronjonesweb An Introduction to Plugin Development Text Editors
8. @cameronjonesweb An Introduction to Plugin Development That’s All We Need To Get Started
9. @cameronjonesweb An Introduction to Plugin Development WordPress Hook System The WordPress hook system is how WordPress knows when to run your code There are two types of hooks • Actions • Filters
10. @cameronjonesweb An Introduction to Plugin Development WordPress Hooks - Syntax & Parameters • Hook name • Callback • Priority • Arguments
11. @cameronjonesweb An Introduction to Plugin Development WordPress Hooks - Actions Actions are like an event, allowing you to run your code when something specific occurs
12. @cameronjonesweb An Introduction to Plugin Development WordPress Hooks - Filters Filters are like a sieve, allowing you to change data before it gets used
13. @cameronjonesweb An Introduction to Plugin Development WordPress Hooks - Actions
14. @cameronjonesweb An Introduction to Plugin Development WordPress Hooks - Filters
15. @cameronjonesweb An Introduction to Plugin Development WordPress Hook System Pro Tips! • Add your own hooks to allow other developers to extend your plugin developer.wordpress.org/plugins/hooks/ custom-hooks
16. @cameronjonesweb An Introduction to Plugin Development Can We Build Our Plugin Yet?
17. @cameronjonesweb An Introduction to Plugin Development Building Our Plugin • Set up the file structure • Add the plugin file header • Write our code!
18. @cameronjonesweb An Introduction to Plugin Development Set Up Our File Structure • Create a folder inside wp-content/plugins for our plugin • Create a PHP file in our folder • Create a CSS file in our folder • Copy our logo into the folder
19. @cameronjonesweb An Introduction to Plugin Development Set Up Our File Structure Pro Tips! • Make the folder name as unique as possible to avoid conflicts with plugins on WordPress.org • Use the same name for the folder and the PHP file
20. @cameronjonesweb An Introduction to Plugin Development Add The Plugin File Header The Plugin File Header provides WordPress with important information about our plugin. It is added to the main PHP file for the plugin.
21. @cameronjonesweb An Introduction to Plugin Development Plugin File Header
22. @cameronjonesweb An Introduction to Plugin Development Plugin File Header Pro Tips! • Your plugin will need to be licensed under the GPL v2 (or later) if you wish to distribute it
23. @cameronjonesweb An Introduction to Plugin Development Prevent Direct File Access
24. @cameronjonesweb An Introduction to Plugin Development Load Our Custom Styles On The Login Page
25. @cameronjonesweb An Introduction to Plugin Development Load Our Custom Styles On The Login Page Pro Tips! • Make your function and variable names as unique as possible to avoid conflicts with other plugins and themes
26. @cameronjonesweb An Introduction to Plugin Development Replace The Logo On The Login Page
27. @cameronjonesweb An Introduction to Plugin Development Change The Link The Logo Goes To
28. @cameronjonesweb An Introduction to Plugin Development Change The Logo Link Text
29. @cameronjonesweb An Introduction to Plugin Development Tada
30. @cameronjonesweb An Introduction to Plugin Development Can I Release This On WordPress.org?
31. @cameronjonesweb An Introduction to Plugin Development Can I Release This On WordPress.org? Pro Tips! • Your plugin should adhere to the plugin guidelines developer.wordpress.org/plugins/ wordpress-org/detailed-plugin- guidelines • You will need to learn how to use SVN developer.wordpress.org/plugins/ wordpress-org/how-to-use-subversion
32. @cameronjonesweb An Introduction to Plugin Development Can I Release This On WordPress.org? Pro Tips! • Adhere to the WordPress coding standards make.wordpress.org/core/handbook/best -practices/coding-standards • Make sure your plugin is translatable developer.wordpress.org/plugins/ internationalization/localization
33. @cameronjonesweb An Introduction to Plugin Development Can I Release This On WordPress.org? Pro Tips! • Use nonces and capability checks when processing forms • Always escape and sanitise user input developer.wordpress.org/plugins/security
34. @cameronjonesweb An Introduction to Plugin Development WordPress Plugin Development For Beginners skl.sh/2IrEvrA
35. @cameronjonesweb An Introduction to Plugin Development Links For demo code and slides visit: mongoosemarketplace.com/wcbne19