Home Segments Index Top Previous Next

817: Mainline

Now, suppose that you attach the aspect adapter to an instance of the ViewSubclass class, noting that the ViewSubclass class has an update: method defined in Segment 810.

V := ViewSubclass new. 
V model: A. 

Now, if you change the value of the fCalories variable in the food, via an fCalories: message, the view is notified by way of the attached aspect adapter, and the view obtains the current value of the fCalories instance variable through that same aspect adapter:

F fCalories: 27. 
Sample viewer receiving #value update message 
Value, determined in viewer, is 27 

Thus, fCalories: sends changed: to the food instance, which sends update: to the aspect adapter, which sends update: to the viewer, which sends value back to the aspect adapter, which sends fCalories to the food instance.