Custom data source provider

I have some data that comes through a Web Service and it is cached locally using the isolated storage. For me it seems like a good scenario for implementing a custom data source provider: look for the data in the cache, if the data is stale get it from the web service.

My questions are:
1. How is the error mechanism working For example, if an exception is raised during the connection to the web service, how do I notify about this error I have thought that Error property will automatically have a reference to the exception raised during BeginQuery (something like asynchronous web service error mechanism).
2. How about asynchronous retrieval The base class DataSourceProvider doesn't have built-in support for asyncronous data retrieval like Object/XmlDataProvider have so it seems that I have to implement it myself.

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Custom data source provider

Freakie

I think you've asked a similar question.

1) In your subclass, provide an error in the OnQueryFinished override.

2) You have to implement async yourself...you can snif the implementation using Reflector to see how we do it for XML/Object Data provider.
Custom data source provider

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