Comment #6 on issue 884 by benjamin...@gmail.com: The Roassal presentation should react to custom ports http://code.google.com/p/moose-technology/issues/detail?id=884
I had been considering something like a #andSelect: operation similiar to #andShow:, but your first example "on: #customPort do: [ :view :customValue | ... ]" would work better, tying it more closely to a particular view.
Your example in Comment 5 works fine here and will do for now to integrate into my application. thanks.