In this chapter, we've combined the concepts from Chapter 1 with many of the technologies from the last chapter to implement about half of the framework that we designed in Chapter 2. At this point, we have enough functionality for a business developer to build object-oriented systems that support useful concepts such as the following:
n-Level undo
Business rule tracking
Data binding
Change tracking
Strongly typed collections
Editable and read-only objects
Root and child objects
In Chapter 5, we'll finish the business framework by implementing a DataPortal and then enhancing the classes we created in this chapter to understand the DataPortal and data access concepts. From Chapter 6 on, we'll focus on designing and building a simple business application that illustrates how the classes in our framework can be used to build distributed, object-oriented systems.