Ahh, sorry I wasn't clear. I was referring to the mix-in in general.

I think in the context-as-an-object case specifically, the view close handler should definitely not destroy the context. In memory management, generally the party responsible for creating the object should also be the one to clean it up.

(In the context-as-a-constructor function, bindContext is the one constructing the context, so should also take care of the cleanup).