A presentation from Iowa Code Camp 2010 by Kenny Younger (@kenny) and Andy Brudtkuhl (@abrudtkuhl)

1. Intro To WordPress Development Kenny Younger (@kenny) & Andy Brudtkuhl (@abrudtkuhl)

2. What does WordPress look like to the users? Let’s take a look!

3. Database

4. Database Schema Source: SchemaBank.com

5. File Structure

6. / wp-admin/ wp-content/ plugins/ Each plugin usually has its own directory themes/ Each theme has its own directory uploads/ Created on first upload (default location) wp-includes/ wp-config.php

7. wp-config.php define('WP_ALLOW_MULTISITE', true);

8. Debugging made easy Debugging flags added to wp-config.php: define( 'WP_DEBUG', true ); define( 'SCRIPT_DEBUG', true ); define( 'SAVEQUERIES', true ); $wpdb->queries “All” hook: add_action( 'all', create_function( '', 'var_dump( current_filter() );' ) ); Core Control Plugin: http://wordpress.org/extend/plugins/core-control/ Dump Environment Plugin: http://wordpress.org/extend/plugins/dump_env/ Source: http://www.andrewnacin.com/2010/04/23/5-ways-to-debug-wordpress/

9. WordPress Themes What are themes? A way to skin WordPress

10. What’s In A WordPress Theme? WordPress themes are a combination of PHP, CSS, and image files Requirements: HTML CSS Some PHP

11. Anatomy Of A WordPress Theme

12. Theme Structure Index.php includes header.php Includes sidebar.php Includes footer.php

14. tag.php

15. Search Results

16. search.php

17. 404

19. The Stylesheet – style.css The comment headers in the style.css provide meta info to WP are are REQUIRED Thisstylesheet also controls the layout and design elements of your theme…

20. Functions.php Contains theme related functions and commonly is used to generate dynamic sidebars

21. The Loop If (havePosts) show post stuff Else nothing here! End if

23. the_permalink()

24. the_content()

25. the_excerpt()

27. What Is A WordPress Plugin? Plugins are used to add or enhance functionalities of your WordPress site

28. The Plugin Directory http://wordpress.org/extend/plugins/

29. The Plugin API The API provides “Hooks” into WordPress No more hacking the core Made up of Actions and Filters Actions = functions triggered by events ie: Call function on user log in Filters = functions that modify information ie: Add facebook share button before post

30. Plugin Data Sometimes it’s necessary to store data… For large amounts, create a new database table For small amounts, use WordPress “Options” – a table with key/value pairs

31. Admin Menus Custom option panels for users to update settings for your plugin Adds options in WordPress Admin Dashboard

32. Users & Roles & Capabilities WordPress is designed to handle multiple users – from admin and editors to subscribers 5 Pre-Defined Roles Administrator Editor Author Contributor Subscriber http://codex.wordpress.org/Roles_and_Capabilities

33. Custom Fields Allow attaching meta-data to posts. http://www.smashingmagazine.com/2010/04/29/extend-wordpress-with-custom-fields/

34. Custom Post Types Used for: Real Estate Listing Event Calendar Movie Database Issue Management / Ticket System Etc.

35. Custom Post Type Options label singular_label description public – query-able from public? menu_position menu_icon hierarchical query_var capability_type – permissions supports rewrite taxonomies register_meta_box_cb permalink_epmask

36. Custom Post Types – Integration with the loop <?php $loop = new WP_Query( array( 'post_type' => my_custom_post_type', 'posts_per_page' => 10 ) ); ?> <?php while ( $loop->have_posts() ) : $loop->the_post(); ?> <?phpthe_title( '<h2 class="entry-title"><a href="' . get_permalink() . '" title="' . the_title_attribute( 'echo=0' ) . '" rel="bookmark">', '</a></h2>' ); ?> <div class="entry-content"> <?phpthe_content(); ?> </div> <?phpendwhile; ?>

37. Taxonomies What are taxonomies? register_taxonomy() Shows up in menu system Demo register_taxonomy( 'actor', 'post', array( 'hierarchical' => false, 'label' => __('Actors', 'series'), 'query_var' => 'actor', 'rewrite' => array( 'slug' => 'actors' ) ) );

38. Core Development Versioning 0.1 increments Based on time, not features Generally every 5-6 months 0.0.1 – usually security fixes, other small bug fixes Always update!! Mailing lists: http://codex.wordpress.org/Mailing_Lists Trac: http://core.trac.wordpress.org

39. Resources Planet - planet.wordpress.org WordPress Codex – codex.wordpress.org WordPress Forums – wordpress.org/support All Things WordPress- wordpress.alltop.com Core Development Blog – devel.wordpress.org

40. August 7th, Downtown Des Moines Public Library

41. Thanks!!! Kenny Younger (@kenny) & Andy Brudtkuhl (@abrudtkuhl)