Question

I have a web service that will be consumed by some application (web site currently).

The calls are almost all specific to a certain client but still the same. So one call might be getAllFoo() but I would need some parameter to say from which client the Foo is.

It would become bothersome quickly if I just add a standard parameter to all calls so I was hoping to do it a little bit DRY and automatic. Something that would be included in all service calls.

Is IDispatchMessageInspector the right thing for me here? What kind of info could that include and can I access that info inside the methods?

Should I create some sort of attribute perhaps for the calls?

If anyone could point me towards a solution for this it would be great.

Edit

Another solution I’m thinking off.

Where the service call to a specific client happens on the consumer side, it will be known at instanceCreation so I could instance the ServiceClient with a known client.

Could I use this solution for the ClientBase<> extender somehow.

Let’s say I’m serving Domain1 (let’s call the client Domain to not confuse it with a serviceclient/consumer) I create a InformationProvider consumer side that has a ClientBase<IInformationService> field. I ensure that the DomainName (domain1) is set at construction so I could parhaps do the same thing when instancing the ClientBase<IInformationService> so It somehow let’s the service know what domain I’m calling for.

I’m just still learning about WCF so I’m not sure how one would do this.

Answer 1

I can understand that you want to keep you solution simple and tidy, but ultimately – as you say yourself –

… I would need some parameter to say from which client…

The obvious and simplest solution is to include a client parameter on all your service calls where it is required. Surely there’ll be service calls that don’t require the client parameter, and in those cases you don’t need to include the parameter.

You may be able to do something clever where a client identifier is passed discreetly under the covers, but beware of doing unnecessarily clever things. I would pass the client as a simple parameter because it is being used as a parameter. Two reasons come to mind:

1. if someone maintains your code they quickly understand what’s going on.
2. if someone needs to use the service it is obvious how to use it.