The document discusses the importance of using core functionality plugins in WordPress development to enhance theme capabilities while minimizing user issues when switching themes. It introduces the TGM Plugin Activation library for requiring and recommending plugins within themes, ensuring easier installation and management for users. Additionally, it covers the use of wp_filesystem for secure file writing methods to mitigate security risks associated with local file changes.

1. GOT AWESOME
THEME
FUNCTIONALITY?!
IT PROBABLY
NEEDS A PLUGIN
Core Functionality Plugin + TGM Plugin Activation + WP_Filesystem
By: Thomas Griffin / @jthomasgriffin / thomasgriffinmedia.com

2. A LITTLE BIT!
ABOUT ME
I DEVELOP WORDPRESS FOR A LIVING
I hold a degree in Business Management and
Administration from the best college in the
world – Appalachian State University.
I officially started September 2010, but have
been at this whole developing thing for around
two years.
Fun fact: I am a scratch golfer.

3. THE DOWN!
AND DIRTY
WHERE ARE WE GOING TODAY?
1. Core Functionality plugin
1. Anatomy of a plugin
2. What is a core functionality plugin and
why is it important?
2. TGM Plugin Activation class
1. Leveraging plugins for your users
2. Requiring/recommending plugins with
your themes
3. Practical examples
3. WP_Filesystem (if we have time)
1. Brief tutorial and how-to’s
4. Q and A

4. PLUGINS, PLUGINS,! PROTECT YOURSELF
PLUGINS
!
A core functionality plugin contains
(what should be) theme
CORE
independent elements of a site.
FUNCTIONALITY
PLUGINS
This can be a range of things, but
generally this includes shortcodes,
PROTECT
metaboxes and CPT’s/CT’s.
YOU
FROM
Why? Users expect these things to
ANGRY, SNARKY, UPSET, RUDE, INSENSITIVE
remain when switching themes. At
IRATE, IRRITATED, ANNOYED & PEEVED
worst, this saves you hours of
support calls.
USERS AND CLIENTS
Themes shouldn’t be the end-all-
be-all for your projects. Ever.

5. BECAUSE IF YOU DON’T, THIS HAPPENS…

6. BUILDING A PLUGIN
PLUGIN REQUIREMENTS
• Plugin Name
• Plugin URI
• Description
• Author
• Author URI
• (optional) License
• (optional) License URI

7. BUILDING A PLUGIN (CONT)

8. BUILDING A PLUGIN (CONT)

9. BUILDING A PLUGIN (CONT)
A COUPLE OF USEFUL FUNCTIONS
• plugin_dir_path( __FILE__ )
• __FILE__ is a PHP constant that gets the full path and filename
of the current file
• plugins_url( $path, $plugin )
• $path is the path to whatever you are calling (e.g. an image or
script)
• $plugin is the path to the plugin (we can use __FILE__ here)
• Both are documented in the Codex – look them up

10. BUT WAIT
I KNOW YOU ARE THINKING…
How can I include plugins within a theme?
How will users know how to install them?
How can I give users a way to install them?
What about private plugins?
Can I pull plugins from WordPress repo?
What about pre-packaged plugins?
ENTER TGM PLUGIN ACTIVATION

11. TGM PLUGIN!
ACTIVATION
TGM PLUGIN ACTIVATION is a PHP
library that allows you to easily require or
recommend plugins for your WordPress
themes (and plugins). It allows your users
to install and even automatically activate
plugins in singular or bulk fashion using
native WordPress classes, functions and
interfaces. You can reference pre-
packaged plugins, plugins from the
WordPress Plugin Repository or even
plugins hosted elsewhere on the internet.
http://tgmpluginactivation.com

13. WHY !
USE IT?
SIMPLE: IT IS SILLY NOT TO
The library uses all of WordPress’ own
classes and methods in the installation
process.
It even works for those users who have
strict permissions.
And it works for MultiSite, too.

14. WHY !
USE IT? (CONT)
The are a number of benefits to using a
plugin for your functionality vs. including it
directly in the theme:
1. To reiterate, it saves you from having to
deal with “urgent” messes later
2. Easy updating and management (WP
repo or even your own private repo)
3. If the project allows, you can share your
code with others
4. Users can’t mess their own site up (no
WSOD if they edit it incorrectly)
Let’s dive into the library, shall we?

15. WP_FILESYSTEM
WP_Filesystem is a function used to call various WP_Filesystem_*
classes depending on a user’s server setup.
There are 4 different “methods” that WP_Filesystem uses:
1. Direct
2. FTP
3. FTP Sockets
4. SSH2
WP_Filesystem will automatically choose the best method based
on the server setup.

16. WHY WP_FILESYSTEM?
Writing local files, if not done correctly (err, not done with
WP_Filesystem), poses security risks.
Why? It is highly unlikely that your webserver user and your user
account are one in the same. Consider shared hosting – it has a
webserver user and lots of other users (like you on it). Give the
webserver user ownership of your files and now everyone has
access to them – no bueno.
In effect, WP_Filesystem makes sure that you in fact are the one
making changes to your files.

17. USING WP_FILESYSTEM?
Due to a lack of time, we’ll dive into the TGM Plugin Activation
library to see how WP_Filesystem is setup to process plugin
installations.
There is one important function you need to know, though:
request_filesystem_credentials( $form_post, $type, $error = false,
$context, $extra_fields )
And once setup, you can call the WP_Filesystem object:
global $wp_filesystem

18. WRAPPING UP
1. Use a core functionality plugin when working on projects
2. Don’t include functionality in a theme that should be in a plugin
3. Require/recommend plugins within your distributed/
commercial themes with the TGM Plugin Activation library
4. Use WP_Filesystem to do any local file writing within your
plugins or themes

19. THANKS!
FOR !
LISTENING!
QUESTIONS?
http://thomasgriffinmedia.com
http://twitter.com/jthomasgriffin
http://facebook.com/thomasgriffinmedia