Changing the category permalink structure

Question

Hopefully another simple one, I have some nested categories, like this:

- category-a
    - category-b
         -category-c

The permalink for category-c is as follows:

http://<domain>/category/category-a/category-b/category-c/

What I'd really like is for the permalink to not include any parent categories, instead it would become this:

http://<domain>/category/category-c/

Is there a way this can be achieved? I have some categories that do nothing but group sub-categories together, thus I don't really want them displaying to my users.

Many thanks!

Answer 1

The following code changes all links to category archives so they don't include the parent category:

add_filter( 'category_link', 'wpse7807_category_link', 10, 2 );
function wpse7807_category_link( $catlink, $category_id )
{
    global $wp_rewrite;
    $catlink = $wp_rewrite->get_category_permastruct();

    if ( empty( $catlink ) ) {
        $catlink = home_url('?cat=' . $category_id);
    } else {
        $category = &get_category( $category_id );
        $category_nicename = $category->slug;

        $catlink = str_replace( '%category%', $category_nicename, $catlink );
        $catlink = home_url( user_trailingslashit( $catlink, 'category' ) );
    }
    return $catlink;
}

Answer 2

Alas that won't work, although I did briefly look at this advanced permalinks wordpress plugin.

http://bit.ly/d9WWr

Does seem to mention more control over category level permalinks, maybe something to check out.

Answer 3

Damn, so Toby Howarth just found this link for me, a bit of a hack but it does what I need it to.

http://wordpress.org/support/topic/remove-parent-category-from-permalink#post-1038484

It involves changing part of wp-includes/category-template.php, not that I'm keen on using hacks but I really don't want the parent categories appearing in the category permalink structure.