This document discusses how to create a basic WordPress plugin. It explains the anatomy of a plugin including the main PHP file, folders for JS, CSS and PHP files. It demonstrates how to add actions, filters and shortcodes to a plugin. Actions add functionality on certain WordPress hooks or actions. Filters modify content by filtering data through a function. Shortcodes allow inserting dynamic content via a shortcode tag. The document provides examples of adding an action, filter and shortcode to a plugin. It recommends further exploration of plugins, learning from others, and references for more information.

1. Creating Your First
WordPress Plugin
Colin Loretz

2. Why?

3. codex.wordpress.org
Know it
Breathe it
Live it

4. Anatomy of a Plugin
Plugin Folder Name
• main php file
• js folder
• css folder
• php folder

5. Anatomy of a Plugin
reno-wordcamp
• reno-wordcamp.php
• js
• css
• php

6. Main PHP File
<?php
/*
Plugin Name: Your Plugin Name Here
Plugin URI: Your Plugin URI
Version: Current Plugin Version
Author: You
Description: What does this do?
*/

7. reno-wordcamp.php
<?php
/*
Plugin Name: Reno WordCamp
Plugin URI: http://renotahoewordcamp.com
Version: v1.0
Author: <a href = “http://colinloretz.com”>Colin Loretz</a>
Description: A plugin for Reno WordCamp
*/

8. Adding an Action
function addHeaderCode() {
echo ʻHello from the clouds!ʼ;
}

9. Actions & Filters
//Actions
add_action(ʻwp_headʼ, ʻaddHeaderCodeʼ, 1);
?>

10. Adding a Filter
function addContent($content=ʼʼ) {
$content .= ʻ<p>Colin is at WordCamp.</p>ʼ;
return $content;
}

11. Actions & Filters
//Actions
add_action(ʻwp_headʼ, ʻaddHeaderCodeʼ, 1);
//Filters
add_filter(ʻthe_contentʼ, ʻaddContentʼ);
?>

12. Adding a Shortcode
[renowordcamp]

13. Adding a Shortcode
function renoShortcode($att) {
extract(shortcode_atts(array(
'foo' => 'no foo',
'bar' => 'default bar',
), $atts));
return quot;foo = {$foo}quot;;
}

14. Add the Shortcode
//Actions
add_action(ʻwp_headʼ, ʻaddHeaderCodeʼ, 1);
//Filters
add_filter(ʻthe_contentʼ, ʻaddContentʼ);
//Shortcodes
add_shortcode('renowordcamp', 'renoShortcode');

15. Going Further
Saving & Storing Explore Plugins
Learn from others
Options
Post Metadata
Database

16. Want More?
• Wordpress.org (and codex)
• WP-Hacker email list (google it)
• WordPress Planet

17. Find Me
@colinloretz
www.colinloretz.com