The slides from my presentation to the Las Vegas Developers meetup group

1. An Introduction To
WordPress Development
by John Hawkins
Monday, October 15, 12

2. I’m John
I run 9seeds.com / WordPress development
I speak at WordCamps nationally
I started the Vegas WordPress group (260+)
I’ve got 1 wife, 2 kids, 1 cat, 3 dogs, self-
diagnosed ADD and OCD. SQUIRREL!
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3. The Misconception
About WordPress
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4. WordPress is
Just For Blogging
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5. That is...
Wrong
Not true
Complete BS
Erroneous
False
All of the above
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6. What is WordPress
A content management system
An open source project
Created by and for the community
Free to use for anything from a personal
blog to a Fortune 500 web site
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7. .com vs .org
.com is a service .org is downloadable
provided by a For software you can use
Profit company on any server
.com doesn’t allow .org allows unlimited
install of your own freedom to do as you
plugins / themes wish
.com is updated for .org requires you
you automatically update the software
yourself
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8. Why I Use WordPress
70,000,000+ sites = big pool of clients
Easy to use for end users
Helpful community / access to support
Can be made to do most anything
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9. Let’s Get Started
But first, a couple rules
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10. The First Rule of
WordPress Development
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11. The First Rule of
WordPress Development
You do not edit core files
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The reason for this is that WordPress typically releases 3 major updates per year along with a handful of security
releases. Any core files you edit will be overwritten with the standard WP upgrade process

12. The Second Rule of
WordPress Development
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13. The Second Rule of
WordPress Development
You DO NOT edit core files
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Please see slide 11...

14. Standard
WordPress
Structure
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Unless you are making a change to submit as a patch to the core team, you should most likely only be messing
with files in the plugins or themes folders

15. Let’s Build a Plugin
Plugins can be a
single file or multiple
directories of files
Create a folder and a
php file with matching
name inside the
plugins folder
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16. my-plugin.php
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This information is all you need in order to tell WordPress that this file is a plugin.

17. Monday, October 15, 12
With that little bit of info, our plugin is ready to be activated. Although it won’t do anything yet.

18. Add a Filter
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Added a filter which is going to edit the content and run our function in a specified order

19. Create a CSS
Folder & File
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20. Add an Action
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We’ve told WordPress that when it enqueues the rest of the scripts, enqueue ours, too.

21. The End Result
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22. Some Plugin Resources
Don’t write code that WordPress already handles
http://codex.wordpress.org/Function_Reference
Know your hooks and filters
http://adambrown.info/p/wp_hooks
Check out the WordPress coding Standards
http://codex.wordpress.org/WordPress_Coding_Standards
Monday, October 15, 12
- Don’t reinvent the wheel
- 1600 hooks and filters
- Hooks are actions that fire at specific spots in the code.
- Filters typically modify content before displaying it on screen or writing to the database.

23. Let’s Build a Theme
Like plugins, a theme
can be one or many
files
Themes add design to
your site
Themes can also add
functionality
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24. style.css
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This is the only info you need to tell WordPress about our theme

25. Monday, October 15, 12
With that little bit of info, our theme is ready to be activated
what happens if we activate now?

26. Monday, October 15, 12
D’oh! We didn’t add anything to our index file yet...

27. index.php
Get started by adding
the header/footer
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28. Post Layout, part 1
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have_posts() checks page for available content
while have_posts will loop through each post
the_title() / the_content()

29. Post Layout, part 2
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This is displayed if no posts were on the page
_e() allows for translations

30. Hey, We Have a Page!
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It may be ugly, but you can see the beginnings of our site.

31. Add Some Style
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Adding the most basic amount of style, and activating our plugin

32. http://codex.wordpress.org/Template_Hierarchy
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Knowing what template is being used is VERY important.

33. Some Theme Resources
The WordPress theme community
http://make.wordpress.org/themes/
WordPress CSS Coding Standards
http://make.wordpress.org/core/handbook/coding-standards/css/
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34. Save Some Time,
Create a Child Theme
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Creating a child theme only needs the Template tag
Importing the style sheet is a huge shortcut

35. Monday, October 15, 12
the original twentyten theme with our plugin activated

36. Monday, October 15, 12
The Child theme changes colors, moves menu location, moves sidebar, made it 3 column
doesn’t affect the parent theme at all

37. Questions?
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38. Want to Learn More?
http://vegasgeek.com/skillshare-schedule
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39. Thank You!
Email: john@vegasgeek.com
Twitter: @vegasgeek
Facebook: /vegasgeek
I’m sensing a pattern...
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