Réponses:
le crochet est le même, save_post
assurez-vous simplement que votre type de message est ex:
add_action('save_post','save_post_callback');
function save_post_callback($post_id){
global $post;
if ($post->post_type != 'MY_CUSTOM_POST_TYPE_NAME'){
return;
}
//if you get here then it's your post type so do your thing....
}
Nouvelle solution, à partir de WP 3.7: save_post_{$post_type}
add_action( 'save_post_my_post_type', 'wpse63478_save' );
function wpse63478_save() {
//save stuff
}