Saw Jesse Liberty (Microsoft Silverlight Evangelist) speaking at a joint UK Silverlight User Group/London .Net User Group event this week. The topic was “Silverlight 4, MVVM and TDD: A Brave New World”.
Jesse was a very engaging speaker and not at all phased by the large audience of over 200. His jokes about “us Americans” and comments about driving in London went down well and showed he’s good at connecting with his audience as well as that he’s enjoying his trip around Ireland and the UK.
MVVM is looking like a good fit for Silverlight or WPF applications. Jesse’s emphasis in the talk was
1. The View is entirely in Xaml and can be “blended” or styled in Expression Blend by a designer.
2. The ViewModel extracts the logic that might have been in the code-behind allowing it to be written with full test-first red-green-refactor TDD instead of being cobbled together to suit the order in which the UI is designed.
With Silverlight 4 being released earlier in the week the audience was mostly developers with some experience in .NET seeing how Silverlight can be used not just for a bit of sparkle of the Internet but for real applications. So the talk was a timely illustration that new design patterns can allow us to continue to use the agile techniques that have allowed us to write quality code as we move to building richer user experiences.