The ViewModel Distilled

A MVVM starter project for your consumption.

For the past few weeks, I have spending my evenings learning Silverlight 3.  It has been fun & insightful.  I had experience developing in Adobe Flex, so aside from the syntax it was a smooth transition.  One of the goals I had when I started was understanding how to leverage the ViewModel pattern in my applications.  ViewModel architecturally structures your code in a manner similar to the Model-View-Controller & Model-View-Presenter patterns.  The benefit of using ViewModel is that it capitalizes on the context (client applications) and features (data binding) of rich internet applications.  However learning the pattern was a bit frustrating.  There was a shortage of programmatic examples for implementing the ViewModel pattern in Silverlight.  I found a few for Silverlight 2, and fewer for version 3.

There were a few excellent & helpful resources:

Model-View-ViewModel In Silverlight 2 Apps

ViewModel Pattern in Silverlight using Behaviors

Using Model – View – ViewModel with Silverlight

These sources greatly helped my conceptual understanding & implementation of the ViewModel pattern.  However, each implemented the pattern in slightly different ways using different requirements.  Without a standardized implementation, the learning curve was longer than I expected.

I got through it though (yay!).  I managed to create a couple different applications using ViewModel.  After writing the third application though I was getting tired of recreating the same classes and directory structures.  What I needed was a template.  Something I could open when I needed it and start coding.  Most of the online sources I reviewed were very rich solutions so they did not lend themselves as ‘starter’ projects.  Others did not provide a complete project I could reuse.  So I opted to create my own ‘distilled’ version of the ViewModel pattern in Silverlight 3 using Microsoft’s Visual Web Developer 2008 Express Edition.  The application itself is very basic (it only displays an employee’s name).  But using this project as a template allows me to shave a few minutes of writing whenever I create a new ViewModel-based Silverlight application.

Feel free to download it and tweak it to your desires:

  http://cid-a537fc3c292692a7.skydrive.live.com/embedrow.aspx/.Public/MVVM|_Simple.zip

Some time after I created the template project, I stumbled upon the Silverlight Model-View-ViewModel Toolkit.  It is an open source project designed to solve the problems I was facing when I was learning ViewModel.  The toolkit is in its infancy, but worth the look if you are interested in learning about implementing ViewModel in Silverlight.