RefreshUi: reload whole control?

Hey guys, I feel like there must be a simple way to do this, but I can't come up with it at the moment.  I have a widget that is built from a listview.  In my designer.js, I would like to be able to refresh the whole control when somebody makes new selections in the designer.  The only way I can think of to do this is to make an ajax call to a method which generates the new html and returns it, but it seems like I'd be breaking the "Don't Repeat Yourself" rule of programming.  Any more elegant or simpler suggestions would be appreciated.

I'm new to sitefinitiy so it just may be a lack of understanding of the basics.

Like you want the widget in the background behind the modal window to update?