Could someone please provide an example of this?
The way to adapt to the behaviour of the ValueModel used in the ModelViewController (and ModelViewPresenter in DolphinSmalltalk). Say, you have a Person class with two accessors:
Person>>name
^ name.
Person>>name: aString
name := aString.
The pair of accessors (name/name:) is called an aspect. You can treat an aspect as a ValueModel, passing it to UI elements expecting ValueModel. In MVP:
|person adaptor|
person := Person new.
adaptor := person aspectValue: #name.
adaptor value: 'Mister One'.
TextPresenter showOn: adaptor.