Question

If I don’t keep Service Contract, proxy and Service in separate assembly, Service contracts and Proxies resides in Client assembly, And service resides in Service assembly.

If I do not keep data contract in a separate assembly, where should it reside, Client side or Service side?

Can Data Contracts reside in both assemblies?

Answer 1

In a typical, service-oriented scenario, you have the DataContract in your server-side service library. Anyone who will be calling you will be adding a client proxy connection to your service, and thus will be in fact duplicating your DataContract.

So in the “normal” case, you have your “master” DataContract on the server side, and a separate class in each of the client proxies accessing your service. Those client copies are “identical on the wire”, e.g. they serialize into the same message format – which is really all there is between your client and your server – a serialized message being sent back and forth.

As a service developer, you definitely have to have your DataContract on the server side. But the same really also applies to the service contracts – those also have to be on the server side – otherwise you won’t be able to publish your service interface to the world to be used by anyone who might connect to your service.

I would suggest the following at least two projects for each server:

• a class library which contains the service contracts (IService interfaces), the data contracts, and possibly the fault contracts
• a class library or self-hosted EXE (console app) that contains the actual service implementation (the classes implementating the service interfaces)

Marc