This simple snippet of code either added as a plugin or in your themes functions.php script will do the following:
(1) Always show a category on the widget even if no posts in that category
(2) If child categories exist only displays on the widget the category of the current selected parent category.
Note: To make it easier to flow and to improve search engines, might also be worth adding breadcrumb navigation too.
function dunnies_wp_list_categories($cat_args){
$this_cat = (get_query_var('cat')) ? get_query_var('cat') : 0;
$cat_args['child_of']=$this_cat;
$cat_args['depth']=1;
$cat_args['hide_empty']=0;
return $cat_args;
}
add_filter('widget_categories_args', 'dunnies_wp_list_categories', 10, 2);
Hope this helps someone.
