In WordPress with the `publish_{post_type}` (<http://codex.wordpress.org/Post_Status_Transitions>) you can hook into the loop if a post with custom type is published. But `publish_{post_type}` is also triggers if a a post is updated. 

I am basically looking for a way to check the old and new status, within the `publish_post_type` hook. Does anyone have a nifty idea as to how to accomplish that?

I am doing this:

```
function doStuff( $post_ID ) {
    // do stuff
    return $post_ID;
}
add_action( 'publish_ttplaned', 'doStuff' );

```

So basically I need to check the old and new status of the post within the fuction doStuff().