I'm refactoring a tkinter GUI along a MVC design pattern. The Controller module imports a View class, and the View class makes requests to the Controller. I have a few ways of registering a change to an entry widget (StringVar trace, binding, etc.), but what if the widget is deeply nested and the callback is at a much higher level? What is the best way to have a request propagate upwards? For example, what if the View has a Frame that has a Frame that has a Widget that changes status?
The two solutions that occur to me are:
Russian Doll approach: Every inner layer is instantiated with either a reference to the View or the Controller, so the widget can directly make a request (e.g. to ViewReference.call_controller(input), or ControllerAlias.request(input). This leaves a trail of breadcrumbs from View to widget.
Family Tree approach: recursively call the parents and ask if they have an "ask controller to do thing" method. If not, ask their parents. This seems more fragile and awkward.