Consider that you have some graphical interface that represents some data structure. For example a text field:
This field is connected to the data structure through events. I tried to make diagram of this:
Of course, there may be many GUI element and the structure can be complex. What happens is, that when GUI values are changed by user, the structure is updated. When the structure is changed from other source, it notifies GUI of the change.
What do I do to prevent this connections from looping? I thought of having some "silent" setter functions, but this looks dirty. What should the model correctly look like?