Is there a way I can display all categories in the categories widget that comes with wordpress. I do not want to have to edit the core files and I want to stay away from rewriting the widget, but if need be I will. Is there anyway to hook into the widget just to get this functionality.
Not sure what you mean by 'display all categories', i thought it does that by default?
Anyways...you can hook into it, using the following filter hooks:
Both hooks pass the query args to get the categories as an array.
The default is
The dropdown version gets another value:
You'll can hook the same callback to both filters, so that the result is the same no matter if
BTW: The widgets that come with WP out of the box are defined in