WCF RIA Services - switching to Local Store

I have a Silverlight application that uses WCF RIA Services. I'd like to be able to switch the datasource to a local store (for example, SQLite) for demo or UI testing purposes.

At which l开发者_StackOverflow社区ayer should I refactor my code to allow to do this? Is there a way to do this without repeating functionality already present in WCF RIA Services classes (DomainClient, Entity, etc.), or should I create the switch much higher in the abstraction and bypass all of these classes altogether?

Thanks.

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The DomainClient is the hook the framework provided for implementing this kind of switch. However, I don't think I've heard of anybody taking that approach. Instead, the split is often made at the Service layer of applications designed using the MVVM pattern (discussed in this video http://channel9.msdn.com/Series/Silverlight-Firestarter/Silverlight-Firestarter-2010-Session-4-MVVM-Why-and-How-Tips-and-Patterns-using-MVVM-and-Service-Pat).

Also, you might find this thread interesting as it discusses some existing patterns that have been used to persist data to the Silverlight isolated store.

http://forums.silverlight.net/forums/p/219768/524983.aspx#524983