Sample Application: ModularityWithMef.zip (4.95 mb)
Although I have been a hard-core Unity (Dependency Injection) cronie since its conception I have to admit I was very pleased with MEF extensions to PRISM. However, it did force me to rethink some design strategies that I've used since the Smart Client Software Factory - such as using generics to quickly wire-up base classes (you can't use generics with attributes).
Somewhat reluctant at first I scraped my earlier prototype/design and moved forward with a new design that is centered around MEF and PRISM V4 Drop 2. I'll have to build an infrastructure that will minimize refactoring when PRISM V4 is released; particularly since PRISM, MEF and Unity will serve as the main tools.
The sample that is provided in the PRISM V4 Drop 2 looks as follows with the exception of the View on the right. I added a new new "Hello World" view utilizing the MVPVM pattern; I use PRISM/MEF to wire-up the infrastructure.
Note: Module F Imports two Business Logic Layers (DoctorBLL/PatientBLL) which in turn Import their respective Data Access Layers. It then uses these, within its presenter, to populate the view model properties that the two ComboxBoxes are bound to.
The end result after refactoring the sample is as follows:
- The Model instantiates the Presenter
- The Presenter instantiates the View and wires up the view model as applicable
After wire-up the Presenter handles all business logic (you'll find no code in the code-behind files). Below is all of the code required to wire-up the module A view with A)dd, E)dit, D)elete and P)rint buttons. Modules A and E both use the same CRUDControl and each have their own CRUD View Models (derived from CRUDViewModelBase) which permit base functionality to be overridden, i.e., notice that Module E does not have a P)rint button. The only wire-up required for the CRUDControl is shown on line 23 below where the DoctoCRUDViewModel.ParentViewModel is set with a reference.
The only issue I ran into, which will result in a message in the user forum is I couldn't figure out how to [Import] parts in the Bootstrapper - so currently there is some code in the MainWindow code-behind but as soon as I work this out I'll move what little code remains there into the Presenter.
Sample Application: ModularityWithMef.zip (4.95 mb)
Tags:
Categories:
MEF |
MVPVM |
Prototype