Question
- what hook can be used to add a custom button to the 'Publish' metabox on the 'Edit Post' admin page?
Use case
I have a hand-rolled custom post type called ash_newsletter. I want to add a button to the post.php?post={$post->ID}&action=edit admin page for this post type. The button will only appear after the post has been published. The button will only be clickable once. The button will be located in the "Publish" metabox.
My idea is that when the button is clicked, a script will check the current post status and will check that a post_meta, ash_already_ran==false. If both conditions pass, a function will be called that contacts another service. If the function returns true, 'ash_already_ran' will be updated to true.
