Manager Classes, Passive and Active Objects, and Two-Layered Frameworks

This paper presents a new design strategy, which treats relations between classes as objects. This concept has a profound effect on the entire software architecture: Instead of having many active objects that are busy communicating with each other, the architecture is based on active objects which manage less actively sometimes totally passive objects. This arrangement brings system and order into the chaos of uncontrolled object interaction. When applying this concept to framework design, we get frameworks composed of two layers: A layer of classes that carry framework relevant data and pointers, plus a layer of classes that have no data, but manage the relations. Application classes inherit only the data, not the framework methods. Experience from numerous commercial projects indicates that the new approach is effective for rapid generation of production-grade code; it also improves code modularity and maintenance by reducing dependency cycles among application classes.