I'm trying to do something when a category is added to post and saved. I thought that using the
save_post hook would have registered when a category is added to a post, but it doesn't appear to.
When I edit a post and do nothing but change the categories for the post, I don't get the
save_post hook fired (editing the title, body, etc fires the
save_post hook successfully). Is there another way to use
add_filter to detect when a category is added to a post?