This document discusses plugins for WordPress Multisite installations. There are two types of plugins: "gotta-have" plugins that are frequently used or goal-oriented, and "must-use" plugins that are always activated on the entire network. Must-use plugins are placed in the /mu-plugins/ directory and activated for all sites by the super admin, while gotta-have plugins can be activated on individual sites. The document provides examples of plugins that have network-wide impacts and considerations for updating and supporting plugins at scale in a Multisite environment.

1. “Gotta-have”
vs.
“Must-Use”
Plugins for Multisite

2. Hi!
Russell Fair
Developer / consultant
@rfair
r@q21.co

3. Multisite Admins
Multisite allows multiple blogs
or sites to run on a single
install. This presents some fun
new opportunities with
WordPress.

4. Facts
Plugins in Multisite aren't that
much different than in a
single WordPress install.
Within Multisite installations
plugins can extend
WordPress on a site-by-site
basis or across the entire
network.

5. Gotta Haves
Frequently used
Content specific
Goal Oriented
Custom
Other...

6. Network Activation
Only super admin can Install /
Update plugins
User control questionable
Scope on network

7. User Controlled
Can activate / deactivate
User control questionable
Use system for use / feedback

8. WordPress action order
muplugins_loaded After must-use plugins
are loaded
registered_taxonomy For category,
post_tag, etc.
registered_post_typeFor post, page, etc.
plugins_loaded After active plugins and
pluggable functions are loaded

9. /mu-plugins/
# mkdir mu-plugins
.php loader vs.
/* Plugin Name: here*/

10. Network Impact
Domain Mapping
Default Blog
Global Search
Batch Create
Multisite Widgets

11. Keeping up
Impact of plugin update sitewide
Impact of new plugins sitewide
Changes to custom plugins
Future integration / updates

12. Gotchas!
Scaling
Security
Support
Removal of /mu-plugins/

13. Questions

14. Refs
http://codex.wordpress.org/Plugin_API/Action_Reference
http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/
http://wordpress.org/extend/plugins/multisite-global-search/
http://premium.wpmudev.org/project/batch-create
r@q21.co