Category Parent/Child Tree

[iacas]

Short of building my own recursive function, I'd like WordPress to support a method to get a parent/child category ID tree. One function (get_category_parents) already does this except with the names of the categories. Another function, cat_is_ancestor_of in category.php appears to be usable, but I've been unable to get it to work.

In short, I'm trying to solve the problem of figuring out what top-most parent category a blog entry belongs to so that I can do some various things with CSS, sidebars, etc.

​http://nslog.com/2007/09/09/wordpress_category_parents

No Patch. Moved to 2.7

isn't this what child_of does in get_terms() et al?

Use this:

$tree = get_terms( 'category', array( 
   'get'      => 'all', 
   'orderby'  => 'id', 
   'fields'   => 'id=>parent' 
) );

You can pass 'slug' => 'my-slug' for context