Text of Intro to Plugin Development, Miami WordCamp, 2015
1. Intro To Plugin Development Emptying out functions.php Intro
To Plugin Development Topher DeRosia @topher1kenobe
2. Hi, my name is Topher Im a WordPress developer from Grand
Rapids MI @topher1kenobe Intro To Plugin Development Topher DeRosia
@topher1kenobe
3. Just put this code in your themes functions.php file JUST
SAY NO Intro To Plugin Development Topher DeRosia
@topher1kenobe
4. Plugins are packages of code that affect your sites
functionality. Themes are packages of code that affect your sites
design. DO NOT MIX. Intro To Plugin Development Topher DeRosia
@topher1kenobe
5. Plugins are either single files or folders in
/wp-content/plugins Intro To Plugin Development Topher DeRosia
@topher1kenobe
6. Typically inside each plugin folder is a file with the same
name as the folder, plus any other files it needs. Intro To Plugin
Development Topher DeRosia @topher1kenobe
7. In the top of every main plugin file is a header block with
information about the plugin. Intro To Plugin Development Topher
DeRosia @topher1kenobe
8. The only option absolutely required is the Plugin Name. The
others are merely strongly recommended. VERY strongly recommended:
License: GNU General Public License v2 or later License URI:
http://www.gnu.org/licenses/gpl-2.0.html Tags: custom-header,
custom-menu, editor-style, featured-images (etc) Intro To Plugin
Development Topher DeRosia @topher1kenobe
9. The Secret Sauce: Any code you might have put into
functions.php in your theme could go into a plugin.* *with a few
exceptions Intro To Plugin Development Topher DeRosia
@topher1kenobe
10. Example: Intro To Plugin Development Topher DeRosia
@topher1kenobe
11. Longer Example: Intro To Plugin Development Topher DeRosia
@topher1kenobe
12. Explanation: function phlog_scripts() { wp_enqueue_style(
'phlog_styles', plugins_url( '/css/phlog.css' , __FILE__ ) ); }
add_action( 'wp_enqueue_scripts', 'phlog_scripts' ); I made a
function called `phlog_scripts()` Inside it is a function that
properly enqueues a CSS file. wp_enqueue_style takes 2 arguments, a
name I made up and the path to the CSS file. The path to the CSS
file is determined with the WordPress function plugins_url(). Intro
To Plugin Development Topher DeRosia @topher1kenobe
13. Releasing a Plugin A plugin built for release on
WordPress.org must meet a list of requirements. The requirements
are listed at
https://developer.wordpress.org/plugins/wordpress-org/ Best
practices are found in the WordPress Plugin Handbook
https://developer.wordpress.org/plugins/ Intro To Plugin
Development Topher DeRosia @topher1kenobe
14. mu-plugins: mu == must use Plugins that are stored in
mu-plugins are automatically activated, and cannot be deactivated.
The main file of a plugin must be stored directly in the
/mu-plugins/ directory, OR be included. Intro To Plugin Development
Topher DeRosia @topher1kenobe
15. mu-plugins Intro To Plugin Development Topher DeRosia
@topher1kenobe
16. mu-plugins To convert a regular plugin to mu-plugins, put
it in the /mu-plugins directory and then make a new, single-file
plugin that looks like this: Intro To Plugin Development Topher
DeRosia @topher1kenobe
17. Extra Credit: WP-CLI WP-CLI is the command line tool for
WordPress. It can create an empty plugin with the proper header in
place: wp scaffold plugin --prompt This will ask questions like
this: 1/4 : topher-test 2/4 [--plugin_name=]: Topher's Test 3/4
[--skip-tests] (Y/n): Y 4/4 [--activate] (Y/n): Y Success: Created
/home/topher1/topher1kenobe.com/wp-content/plugins/topher-test 1/1
: topher-test Success: Created test files. Intro To Plugin
Development Topher DeRosia @topher1kenobe
18. Real World Example Easy Digital Downloads - Customer
Contact Intro To Plugin Development Topher DeRosia
@topher1kenobe
