Getting Started with the Cron API

WordCamp Saratoga 2014

Transcript

1. @jrtashjian
2. WordPress Cron API
3. WordPress Cron API
4. What’s Cron?
5. * * * * * /path/to/command
6. * * * * * /path/to/command day of the week
7. * * * * * /path/to/command day of the week month
8. * * * * * /path/to/command day of the week month day of the month
9. * * * * * /path/to/command day of the week month day of the month hour
10. * * * * * /path/to/command day of the week month day of the month hour minute
11. # run once a year 0 0 1 1 * /path/to/command
12. # run once a year @yearly /path/to/command @annually /path/to/command
13. @monthly /path/to/command @weekly /path/to/command @daily /path/to/command @hourly /path/to/command
14. Asynchronous Jobs
15. Database Job System Clients Enqueue Workers Dequeue
17. WordPress Cron API
18. Database Job System Clients Enqueue Workers Dequeue
19. Database WP Cron API Plugin Enqueue Site Visits Dequeue
20. WordPress Cron API
21. Using the API
22. 2 Main Functions • wp_schedule_event( $timestamp, $recurrence, $hook, $args ) • wp_schedule_single_event( $timestamp, $hook, $args )
23. 2 Main Functions • wp_schedule_event( $timestamp, $recurrence, $hook, $args ) • wp_schedule_single_event( $timestamp, $hook, $args )
24. 2 Main Functions • wp_schedule_event( $timestamp, $recurrence, $hook, $args ) • wp_schedule_single_event( $timestamp, $hook, $args )
25. 2 Main Functions • wp_schedule_event( $timestamp, $recurrence, $hook, $args ) • wp_schedule_single_event( $timestamp, $hook, $args )
26. 2 Main Functions • wp_schedule_event( $timestamp, $recurrence, $hook, $args ) • wp_schedule_single_event( $timestamp, $hook, $args )
27. Custom Schedule
28. Get Schedules <?php wp_get_schedules(); ?> Array ( [hourly] => Array ( [interval] => 3600 [display] => Once Hourly ) [twicedaily] => Array ( [interval] => 43200 [display] => Twice Daily ) [daily] => Array … )
29. Create a Schedule <?php add_filter( 'cron_schedules', 'cron_add_weekly' ); function cron_add_weekly( $schedules ) { $schedules['weekly'] = array( 'interval' => 60 * 60 * 24 * 7, // 604800 'display' => __( 'Once Weekly' ) ); }
30. Create a Schedule <?php add_filter( 'cron_schedules', 'cron_add_weekly' ); function cron_add_weekly( $schedules ) { $schedules['weekly'] = array( 'interval' => 60 * 60 * 24 * 7, // 604800 'display' => __( 'Once Weekly' ) ); }
31. Create a Schedule <?php add_filter( 'cron_schedules', 'cron_add_weekly' ); function cron_add_weekly( $schedules ) { $schedules['weekly'] = array( 'interval' => 60 * 60 * 24 * 7, // 604800 'display' => __( 'Once Weekly' ) ); }
32. Recurring Event
33. Recurring Event <?php register_activation_hook( __FILE__, 'prefix_activation' ); function prefix_activation() { wp_schedule_event( time(), 'hourly', 'prefix_hourly_event_hook' ); } add_action( 'prefix_hourly_event_hook', 'prefix_do_this_hourly' ); function prefix_do_this_hourly() { // do something. }
34. Recurring Event <?php register_activation_hook( __FILE__, 'prefix_activation' ); function prefix_activation() { wp_schedule_event( time(), 'hourly', 'prefix_hourly_event_hook' ); } add_action( 'prefix_hourly_event_hook', 'prefix_do_this_hourly' ); function prefix_do_this_hourly() { // do something. }
35. Recurring Event <?php register_activation_hook( __FILE__, 'prefix_activation' ); function prefix_activation() { wp_schedule_event( time(), 'hourly', 'prefix_hourly_event_hook' ); } add_action( 'prefix_hourly_event_hook', 'prefix_do_this_hourly' ); function prefix_do_this_hourly() { // do something. }
36. Single Event
37. Single Event <?php add_action( 'prefix_single_event', 'prefix_single_event ); function prefix_single_event() { // do something } wp_schedule_single_event( time() + 3600, 'prefix_single_event' );
38. Single Event <?php add_action( 'prefix_single_event', 'prefix_single_event ); function prefix_single_event() { // do something } wp_schedule_single_event( time() + 3600, 'prefix_single_event' );
39. Single Event with arguments <?php add_action( 'prefix_single_event', 'prefix_single_event, 10, 3 ); function prefix_single_event( $arg1, $arg2, $arg3 ) { // do something } wp_schedule_single_event( time() + 3600, 'prefix_single_event', array( $arg1, $arg2, $arg3 ) );
40. How it works 1. A visitor requests a page on your site. 2. wp_cron() is called 3. spawn_cron() is called 4. One event processed, then removed from queue
41. Strengths
42. Weaknesses
43. When to use it
44. Getting More Accurate
45. define( 'DISABLE_WP_CRON', true );
46. 0 * * * * wget http://yourwebsite.com/wp- cron.php >& /dev/null
47. WP-CLI http://wp-cli.org
48. wp cron command • event list • event delete • event schedule • event run • schedule list
49. wp cron event list >> wp cron event list +----------------------+---------------------+--------------------+------------+ | hook | next_run_gmt | next_run_relative | recurrence | +----------------------+---------------------+--------------------+------------+ | wp_version_check | 2014-10-11 17:50:37 | 2 hours 13 minutes | 12 hours | | wp_update_plugins | 2014-10-11 17:50:37 | 2 hours 13 minutes | 12 hours | | wp_update_themes | 2014-10-11 17:50:37 | 2 hours 13 minutes | 12 hours | | wp_scheduled_delete | 2014-10-11 18:42:25 | 3 hours 5 minutes | 1 day | | wp_maybe_auto_update | 2014-10-11 19:50:00 | 4 hours 12 minutes | 12 hours | +----------------------+---------------------+--------------------+------------+
50. wp shell >> wp shell wp> prefix_do_this_hourly(); wp> $arg1 = "first value"; wp> $arg2 = "second value"; wp> $arg3 = "third value"; wp> prefix_single_event( $arg1, $arg2, $arg3 );
51. Contributing https://make.wordpress.org/core/components/cron-api/
52. Questions? @jrtashjian jrtashjian.com