is there an update_post_meta action

Question

Are there any actions I can hook into for update_post_meta()? I don't see anything obvious in the source. Woocommerce lets you change the featured status of items via ajax from the edit screen. I am using a transient to store the featured items in lieu of querying them every time and I'm deleting that transient on the save_post hook, but it isn't getting fired because of the ajax function that directly updates the post meta. Worst case I can unhook woo's action and recreate it myself with the delete transient call, but I'm wondering if there is another hook i could use.

Answer 1

(See codex) update_post_meta() calls

update_metadata('post', $post_id, $meta_key, $meta_value, $prev_value);

This function is here. And there are plenty of hooks/filters:

(In example of 'post', $meta_type='post')

Before metadata is updated:

update_{$meta_type}_metadata (here) Filter

-If this returns anything other than 'null', the metadata won't save

update_{$meta_type}_meta (here) Action

After metadata is updated:

updated_{$meta_type}_meta (here) Action

updated_post_meta (here) Action

-For posts only

All the actions take ($meta_id, $object_id, $meta_key, $meta_value) as arguments. The filter filters a $check and takes the above as additional arguments.