One of the neat things you can do in BizTalk is to create a map that takes one kind of XML message and transforms it into another. They basically are a wrapper over XSLT and its extension infrastructure. The tool you use to create maps is the BizTalk mapper. In this tool you load in a source and destination schema - which get displayed in treeviews and then you drag elements from the source to the destination to describe how to build the destination message.

Now, in WF - especially when using Silver (the WF/WCF integration layer introduced in .NET 3.5) - you tend to spend alot of time taking data from one object and putting it into another as different objects are used to serialize and deserialize messages received and sent via WCF. This sounds alot like what the BizTalk Mapper does, but with objects rather than XML messages.

I was recently teaching Guerrilla Connected Systems (which has now been renamed Guerrilla Enterprise.NET) and Christian Weyer was doing a guest talk on REST and BizTalk Services. Afterwards, Christian and me were bemoaning the amount of mundane code you get forced to write in Silver and how sad it was that WF doesn't have a mapper. So we decided to build one. Unfortunately neither myself nor Christian are particularly talented when it comes to UI - but we knew someone who was: Jörg Neumann. So with Jörg doing the UI, myself writing the engine and Christian acting as our user/tester we set to work.

The result is the MapperActivity. The MapperActivity requires you to specify the SourceType and DestinationType - we used the Type Browser from CodeProject for this. Then you can edit the Mappings which brings up the mapping tool

You drag members (properties or fields) from the left hand side and drop them on type compatible members (properties or fields) on the right hand side.

Finally you need to databind the SourceObject and DestinationObject to tell the mapper where the data comes from and where the data is going. You can optionally get the MapperActivity to create the destination object tree if it doesn't exist using the CanCreateDestination property. Here's the full property grid:

And thanks to Jon Flanders for letting me crib his custom PropertyDescriptor implementation (why on earth don't we have a public one in the framework?). You need one of these when creating extender properties (the SourceObject and DestinationObject properties change type based on the SourceType and DestinationType respectively).

Here is the activity - I'll clean up the code before posting that.

MapperActivity.zip (37.78 KB)

Feedback always appreciated