Extensible WordPress Plugins

Some hints and tips about how to make your plugins and themes more extensible to other developers so they can build on them or modify them safely.

1. markwilkinson.me | @wpmark Extensible WordPress Plugins WordPress Cumbria – 14th October 2014 #wpcumbria
2. mark wilkinson?
3. markwilkinson.me | @wpmark father
4. markwilkinson.me | @wpmark teacher
5. markwilkinson.me | @wpmark WordPress developer
6. markwilkinson.me | @wpmark
7. markwilkinson.me | @wpmark this talk will cover what is extensibility? why should you be making extensible plugins? how to make your plugin extensible? examples of good practice
8. markwilkinson.me | @wpmark this talk will cover what is extensibility? why should you be making extensible plugins? how to make your plugin extensible? examples of good practice
9. markwilkinson.me | @wpmark this talk will cover what is extensibility? why should you be making extensible plugins? how to make your plugin extensible? examples of good practice
10. markwilkinson.me | @wpmark this talk will cover what is extensibility? why should you be making extensible plugins? how to make your plugin extensible? examples of good practice
11. markwilkinson.me | @wpmark Plugin and / or Theme
12. markwilkinson.me | @wpmark Extensible Plugins
13. markwilkinson.me | @wpmark “one that can be modified or extended without changing the plugin code itself ”
14. markwilkinson.me | @wpmark why?
15. markwilkinson.me | @wpmark https://www.flickr.com/photos/damndirty/10166197684
16. markwilkinson.me | @wpmark preserve future updatability
17. markwilkinson.me | @wpmark how?
18. markwilkinson.me | @wpmark actions & filters
19. markwilkinson.me | @wpmark do_action()
20. markwilkinson.me | @wpmark do_action( $tag, $args );
21. markwilkinson.me | @wpmark add_action()
22. markwilkinson.me | @wpmark add_action( $hook, $function, $priority, $accepted_args );
23. markwilkinson.me | @wpmark example
24. markwilkinson.me | @wpmark $q = new WP_Query( $q_args ); while( $q->have_posts() ) : $->the_post(); ?> <!-- // post output here --> <?php endwhile;
25. markwilkinson.me | @wpmark $q = new WP_Query( $q_args ); while( $q->have_posts() ) : $->the_post(); do_action( ‘wpmark_before_post’, get_the_ID() ); ?> <!-- // post output here --> <?php endwhile;
26. markwilkinson.me | @wpmark $q = new WP_Query( $q_args ); while( $q->have_posts() ) : $->the_post(); do_action( ‘wpmark_before_post’, get_the_ID() ); ?> <!-- // post output here --> <?php do_action( ‘wpmark_after_post’, get_the_ID() ); endwhile;
27. markwilkinson.me | @wpmark function wpmark_add_before_post( $post_id ) { $meta = get_post_meta( $post_id, ‘key’, true ); /* do something with $meta */ } add_action( ‘wpmark_before_post’, ‘wpmark_add_before_post’, 10, 1 );
28. markwilkinson.me | @wpmark apply_filters()
29. markwilkinson.me | @wpmark apply_filters( $tag, $value, $var );
30. markwilkinson.me | @wpmark add_filter()
31. markwilkinson.me | @wpmark add_filter( $hook, $function, $priority, $accepted_args );
32. markwilkinson.me | @wpmark example
33. markwilkinson.me | @wpmark $q_args = array( 'post_type' => ’post', 'cat' => 1 );
34. markwilkinson.me | @wpmark $q_args = apply_filters( ‘wpmark_q_args’, array( ‘post_type’ => ‘post’, ‘cat’ => 1 ) );
35. markwilkinson.me | @wpmark function wpmark_edit_q_args( $args ) { $args[ ‘year’ ] = ‘2014’; return $args; } add_filter( ‘wpmark_q_args’, ‘wpmark_edit_q_args’ 10, 1 );
36. markwilkinson.me | @wpmark conclusion
37. markwilkinson.me | @wpmark when making plugins & themes, remember to…
38. markwilkinson.me | @wpmark do_action() & apply_filters()
39. markwilkinson.me | @wpmark Thank you! Questions: @wpmark (or now!) Slides: markwilkinson.me (soon!)