1. Creating
and
Mark Jaquith
“JAKE-with”
Maintaining
WordPress
@markjaquith Plugins
mark@jaquith.me
markjaquith.com

2. Why?
Pa erns!
Repo…
Sanity.

3. Why make
plugins

4. functions.php
is not the new
my-hacks.php

5. Plugins separate
functionality from
core and themes

6. Plugins
comparmentalize
your code

7. Plugins
[comparmentalize]
your code

8. Plugins
[compart][mentalize]
your code

9. Pa erns

10. <?php
/*
Plugin Name: NAME
*/

11. Encapsulate
with CLASS

12. function your_initials_long_plugin_name_do_thing()
vs.
function do_thing()

13. <?php
/*
Plugin Name: NAME
*/
class CWS_ATL_Plugin {
static $instance;
function __construct() {
self::$instance = $this;
add_action( 'plugins_loaded', array( $this, 'plugins_loaded' ) );
}
function plugins_loaded() {
// Add actions and hooks here
}
}
new CWS_ATL_Plugin;

14. function plugins_loaded() {
add_filter( 'the_title', array( $this, 'the_title' ), 10, 2 );
add_action( 'init', array( $this, 'init' ), 5 );
add_action( 'omg', array( $this, 'is_really_tedious' ), 11, 3 );
}

15. if(!class_exists('CWS_Plugin_v2'))
{class CWS_Plugin_v2{function
hook($h){$p=10;$m=$this-
>sanitize_method($h);
$b=func_get_args();unset($b[0]);fo
reach((array)$b as $a)
{if(is_int($a))$p=$a;else $m=$a;}
return add_action($h,array($this,
$m),$p,999);}private function
sanitize_method($m){return
str_replace(array('.','-'),array('
_DOT_','_DASH_'),$m);}}}

16. <?php
/*
Plugin Name: NAME
*/
if(!class_exists('CWS_Plugin_v2')){class CWS_Plugin_v2{function hook($h){$p=10;$m=$this-
>sanitize_method($h);$b=func_get_args();unset($b[0]);foreach((array)$b as $a){if(is_int($a))$p=$a;else
$m=$a;}return add_action($h,array($this,$m),$p,999);}private function sanitize_method($m){return
str_replace(array('.','-'),array('_DOT_','_DASH_'),$m);}}}
class CWS_ATL_Plugin extends CWS_Plugin_v2 {
static $instance;
function __construct() {
self::$instance = $this;
$this->hook( 'plugins_loaded' );
}
function plugins_loaded() {
// Add actions and hooks here
}
}
new CWS_ATL_Plugin;

17. // BEFORE
function plugins_loaded() {
add_filter( 'the_title', array( $this, 'the_title' ), 10, 2 );
add_action( 'init', array( $this, 'init' ), 5 );
add_action( 'omg', array( $this, 'is_really_tedious' ), 11, 3 );
}
// AFTER
function plugins_loaded() {
$this->hook( 'the_title' );
$this->hook( 'init', 5 );
$this->hook( 'omg', 'is_really_tedious', 3 );
}

19. Defer actions

20. Options in
an array

21. const OPTIONS = 'my_plugin_option_name';
function get_option( $key ) {
$options = get_option( self::OPTIONS );
if ( isset( $options[$key] ) )
return $options[$key];
}
function set_option( $key, $value ) {
$options = get_option( self::OPTIONS );
$options[$key] = $value;
update_option( self::OPTIONS, $options );
}

22. Plugins Repo

23. Community
Karma

24. Professional
Credibility

25. Easy reuse
for you

26. SVN

27. svn checkout h p://plugins.svn.wordpress.org/{plugin-name}
Plugin dev loop
{
svn up
{hackity hack hack}
svn add {new-files}
svn commit -m '{Message about your changes}'

28. /trunk/ for development
Tag your releases

29. /trunk/readme.txt
specifies the stable tag
Stable tag: 2.3

30. === Your Plugin ===
Contributors: markjaquith, nacinbot
Donate link: h p://example.com/paypal
Tags: foo, bar
Requires at least: 3.2
Tested up to: 3.3.1
Stable tag: 2.3
Here is a short description of the plugin. This should be no more
than 150 characters. No markup here.

31. 1. Tag in SVN
2. “Repoint” /trunk/readme.txt

32. Support
forums
wordpress.org/support/view/plugin-commi er/USERNAME

33. assets/banner-772x250.(jpg|png)

34. Sanity

35. Slow down
on the options
cowboyand/or-girl

36. Say hello to my
li le friend:

37. Say hello to my
li le friend:
“no”

38. Encourage
good
behavior

39. Encourage
g o o d
behavior

40. Q&A
Mark Jaquith
“JAKE-with”
@markjaquith
mark@jaquith.me
markjaquith.com