Question

I have a WCF REST-service that is used by a mobile application used in different countries. It’s accepting and returning JSON, and I use StructureMap.

The idea is to create one service instance for all countries, but I need to know what country is calling the service and do some logic on that in the service (for example, determine the connection string to be used).

however, I want to avoid that country code has to be passed with each service request. What are my options here?

Can I, for example, have one endpoint for each country? But in that case, how can I know what endpoint/country code was used to call the service?

Maybe other possibilities?

Answer 1

Multiple endpoints could be a solution, but you need a reliant way of determining which endpoint was actually used. Given the “disconnected” nature of WCF REST services (by that I mean the usage of non WCF types to do the communication and just using the WCF attributes), this would require you to write a WebHostFactory that specifies the country on creation of the service for a given endpoint. What you could to is inspect the WebOperationCurrent.Current instance to get access to information hidden from your method signature. For example:

Uri requestRoot = WebOperationContext.Current.IncomingRequest.UriTemplateMatch.BaseUri;
if (requestRoot.PathAndQuery.Contains("en-us")) {
    // use english locale
}
else if (requestRoot.PathAndQuery.Contains("de-de")) {
    // use german locale
}

You would need a better strategy to determine the actual country/language, but the basic idea is to re-host the same service under multiple paths and inspect those paths within the request using the current WebOperationContext instance.

Edit
From the comments above, I would like to add that you have access to the UserAgent string for the current request using the WebOperationContext. So you could also inspect those information looking for a clue about the requested language. But keep in mind that those “implicit” information are only clues but never clear indications about what the user wants.