See Model-View-Controller
See Scripting
See Document Architecture
See Undo and Redo
Three of the more recent features of the Yellow Box frameworks--scripting, the document architecture, and undo support--have a great deal in common conceptually. This document explains their shared conceptual underpinnings. It does not go into great detail about the specifics of the classes implementing these features or how to use them. Instead it concentrates on the recommended structure of an application and how that structure supports these new features.
This document uses Objective-C to describe specific APIs. However, all scripting, document, and undo APIs are also available in Java. Special issues related to Java are discussed where appropriate, and if Java isn't mentioned specifically, it is because there is nothing special to say about it.
This document begins by describing the Model-View-Controller (MVC) pattern because this pattern informs application design that is most supportive of scripting, document-based applications, and undo. It does not fully describe the MVC design pattern in any formal way, since that's not really its purpose, but it does discuss the pattern enough to give some background for the remaining discussion.