[wataru]

I just went through the Cocoa bindings Currency Converter tutorial, and there's one thing I don't understand.

The tutorial has you make a MyController-style custom object named Controller, which keeps the instance variables and the method used to do the conversion. You instantiate this in Interface Builder, and then add an NSObjectController to manage it. You bind the text fields to the NSObjectController and everything works fine.

But everything also works perfectly fine if you bind the fields to the directly to the instantiated Controller object, bypassing NSObjectController altogether. What's the point of NSObjectController then?