How to writing extensible WordPress code

Our Co-founder and WordPress developer, Mark Wilkinson spoke to the WordPress Cheltenham meetup group about writing extensible WordPress code. This is code that others can extend and modify in a safe way.

Before viewing this slide deck, it is worth making sure you understand how WordPress hooks work. This is a blog post we previously wrote which may be of use.

https://highrise.digital/blog/wordpress-hooks-action-filters/

Transcript

1. How to write extensible WordPress code Mark Wilkinson Co-founder and developer at Highrise Digital https://highrise.digital @wpmark
2. What is extensible WordPress code?
3. “ capable of being extended - dictionary.com
4. “ Code which can be modified or extended, without changing the code itself. - Mark Wilkinson
5. Why write extensibly?
6. So, how do I write extensible WordPress code?
7. Use the force core
8. Use the force core How does WordPress core do extensibility?
9. Hooks
10. Hooks Actions & Filters
11. https://highrise.digital/blog/wordpress-hooks-action-filters /
12. Actions do_action()
13. do_action( ‘my_action_name’ );
14. Filters apply_filters()
15. apply_filters( ‘my_filter_name’, $filterable_thing );
17. apply_filters( 'enter_title_here', __( 'Enter title here' ), $post );
18. function hd_title_here( $title, $post ) { if ( 'post' === get_post_type( $post ) ) { $title = 'Article Title'; } return $title; } add_filter( 'enter_title_here', 'hd_title_here', 10, 2 );
19. Implementing this in your own code
20. Arrays of data HTML Output Function returns
21. Arrays of data HTML Output Function returns
22. $job_posts = new WP_Query( array( ‘posts_per_page => 6, ‘post_type => ‘hd_job’, ) );
23. $job_posts = new WP_Query( apply_filters( ‘hd_job_post_query_args’, array( ‘posts_per_page => 6, ‘post_type => ‘hd_job’, ) ) );
24. Arrays of data HTML Output Function returns
25. while ( $job_posts->have_posts() ) : $job_posts->the_post(); ?> <h1><?php the_title(); ?></h1> <?php endwhile;
26. while ( $job_posts->have_posts() ) : $job_posts->the_post(); do_action( ‘hd_before_job_post’ ); ?> <h1><?php the_title(); ?></h1> <?php do_action( ‘hd_after_job_post’ ); endwhile;
27. while ( $job_posts->have_posts() ) : $job_posts->the_post(); do_action( ‘hd_job_post’, $post ); endwhile;
28. function hd_job_post_content( $post ) { ?> <h1><?php the_title(); ?></h1> <?php } add_action( ‘hd_job_post’, ‘hd_job_post_content’, 10, 1 );
29. remove_action( ‘hd_job_post’, ‘hd_job_post_content’, 10, 1 );
30. Arrays of data HTML Output Function returns
31. function hd_sub_title( $post_id = 0 ) { return get_post_meta( $post_id, ‘subtitle’, true ); }
32. function hd_sub_title( $post_id = 0 ) { return apply_filters( ‘hd_sub_title’, get_post_meta( $post_id, ‘subtitle’, true ), $post_id ); }
33. Template overrides
34. Template overrides https://github.com/GaryJones/Gamajo-Template-Loader
35. Pluggable Functions
36. if ( ! function_exists( ‘hd_function’ ) ) { function hd_function() { // awesome functions stuff here! } }
37. Mark Wilkinson Co-founder & developer at Highrise Digital T: @wpmark & @highrisedigital W: markwilkinson.me & highrise.digital