Chapter 29, “Controllers,” describes the roles of Coordinating Controllers and Mediating Controllers within Model View Controller design pattern that permeates Cocoa. Coordinating Controllers initialize, load, and save the Model and View subsystems. Mediating Controllers manage the flow of data between view objects and model objects to minimize coupling between the subsystems. Cocoa supplies the
NSViewController classes among others to provide reusable implementations of most common coordinating tasks. Cocoa also includes
NSUserDefaultsController, which provide reusable implementations ...