WordPress Hooks

From WordCamp Philly 2015 - Learn to get comfortable working with Action and Filter Hooks in WordPress

1. WordPress Hooks Zac Gordon @zgordon
2. 2000+ Hooks in WordPress
3. http://hookr.io/4.1.1/#index=a
4. 200+ Hooks Actually Use
5. “Anything, Anywhere, Anytime”
6. “Anything, Anywhere, Anytime”
7. “Anything, Anywhere, Anytime”
8. “Anything, Anywhere, Anytime”
9. “Anything, Anywhere, Anytime” Filters }
10. “Anything, Anywhere, Anytime” Actions }
11. Filters vs Actions
12. Filters modify something
13. Actions do something
14. Filters in Core
15. $admin_title = apply_filters( 'admin_title', $admin_title ); … <title><?php echo $admin_title; ?></title> wp-admin/admin-header.php
16. Actions in Core
17. <title><?php echo $admin_title; ?></title> … <?php do_action( 'admin_head' ); ?> … wp-admin/admin-header.php
18. What Is Possible?
19. Read the Codex
20. http://codex.wordpress.org/Plugin_API/Filter_Reference http://codex.wordpress.org/Plugin_API/Action_Reference
21. http://codex.wordpress.org/Plugin_API/Filter_Reference Filters
22. http://codex.wordpress.org/Plugin_API/Action_Reference Actions
23. http://codex.wordpress.org/Plugin_API/Action_Reference Runtime
24. http://codex.wordpress.org/Plugin_API/Action_Reference/init Reference Pages
25. http://hookr.io http://wpseek.com
26. $wp_filter
27. <?php echo "<pre>"; var_export( $wp_filter ); echo “</pre>”;? ?> theme/functions.php
28. $wp_filter
29. $wp_filter http://www.rarst.net/wordpress/debug-wordpress-hooks/
30. Helpful Plugins
31. Simply Show Hooks https://wordpress.org/plugins/simply-show-hooks/
32. WP Query https://wordpress.org/plugins/query-monitor/
33. Back to the Code
34. Power of Search
35. SublimeText Ctrl + Shift + F
36. Okay, Let’s Do Something
37. Deactivate something
39. <?php remove_action( 'wp_enqueue_scripts', 'wptreehouse_badges_frontend_scripts_and_styles' ); ?> theme/functions.php
41. Order Matters
43. .plugin-override { color: #fff !important } theme/style.css
44. theme/functions.php <?php remove_action( 'wp_enqueue_scripts', 'wptreehouse_badges_frontend_scripts_and_styles' ); add_action( 'wp_enqueue_scripts', ‘wptreehouse_badges_frontend_scripts_and_styles’, 9 ); ?>
46. Quick Review
47. remove_action( ‘hook’, ‘function’ )
48. remove_action( ‘hook’, ‘function’ ) add_action( ‘hook’, ‘function’, 10 )
49. Hooks Open WordPress to Your Needs
50. A Few Examples
51. function excerpt_length_example( $length ) { return 15; } add_filter( 'excerpt_length', 'excerpt_length_example' );
52. function body_class_example( $classes ) { if( is_single() ) { foreach( get_the_category( get_the_ID() ) as $cat ) $classes[] = 'cat-' . $cat->category_nicename; } return $classes; } add_filter( 'body_class', 'body_class_example' );
53. function register_my_menus() { register_nav_menus( array( 'footer_menu' => __( 'Footer Menu', 'mytheme' ) ) ); } add_action( 'init', 'register_my_menus' );
54. function my_plugin_page() { add_options_page( 'Page Title', ‘Menu Title', 'manage_options', ‘plugin-slug', ‘my_plugin_page_init’ ); } add_action( 'admin_menu' , 'my_plugin_page' );
55. function publish_post_to_slack( ) { // Connect to Slack API } add_action( 'save_post', ‘publish_post_to_slack’ );
56. https://teamtreehouse.com/
57. Zac Gordon wp.zacgordon.com @zgordon https://teamtreehouse.com/learn/wordpress