CAB to become part of .NET Framework ?
I was looking recently at the Patterns & Practices roadmap when I noticed that there would be no new version of the Composite Application Block because ... it will be included in a future version of the Framework! Now that is great news!
For people who don't know what CAB is, it's a framework similar to Struts or JSF for building smart client (i.e. desktop) applications. It implements a variation of the MVC pattern, the MVP (Model-View-Presenter) with the ingenious addition of use cases in the form of WorkItems. CAB allows applications to be composed of different application modules. Each module can represent a completely different application scenario, e.g front office or analytics and it may implement different use cases as WorkItems and include its own UI elements (views). The main application acts as a shell that provides common functionality and composes the UI elements of the modules. It also routes UI commands and events to the proper modules, handles offline operation and configuration.
Configuration plays an important role in CAB. It specifies which modules should be loaded by the application. This means that an application can provide different functionality to different users just by modifying a configuration file. Or, that a new module can be added just by deploying its assembly and modifying the configuration. The main application doesn't need to know about the new modules at compile time. And, once you store the configuration in the database, you can have dynamic, per user configuration without deploying the configuration to the clients. That's nice!
Until recently, if anyone wanted to create a baseline application platform he would have to invent a lot. How to define the application's entities, handling persistence, how to define the business processes and finally, how to present everything to the client and do it all dynamically. CAB now takes care of the client-side concerns and it looks that soon, .NET framework will do so as well.
I like it!