Since the beginning, there was in getCategoryChildItemList Renderer API the possibility to pass a parameter 'current_category'. The idea was to allow displaying a category which is not part of what the item list will return (typically, if you expire a category, and if you check permission, the category will not be in item list any more).
But the way it was implemented was too inconvenient and it looks never used. So improve several things:
- possibility to pass multiple categories for multi value cases
- reuse renderer to render current categories instead of just reinjecting the url (which is not user friendly)
- implement handling of current_category_list in getCategoryChildItemList to allow caching the result of the Renderer. The only part which is not cached is the rendering of current categories.