Pushing Data to unknown webservices in .NET

Question

Hey guys, here's my requirement:

I have one central App which receives requests from other apps, does something, and then returns data to that App. In its simplest form this data would be an XML document.

Now, at design time, this central App doesn't know which other applications will be making requests.

Each time the Central App receives a request, it will also receive a URL, telling the central App its web service address (see below), so the Central App knows where to push the data to:

http://someapp1.com/UpdateData
http://someapp2.com/UpdateData

Now, I'd like to use either SOAP, or some kind of RESTful implementation, preferably not WCF.

My questions are these:

1. With SOAP can I dynamically, at run time, change the service URL, if the interfaces are all the same?
2. If I can, then how would I go about posting large amounts of XML in a RESTful way?

Answer 1

Is the work of the Central App some sort of very long-running process? Otherwise, why wouldn't Central App expose web methods that simply returned the results as a response, rather than initiating a new call?

someapp1 calls Central.GetMyData(param) ... Central processes ... someapp1 receives SOAP response from Central

This will also help to decouple your system, which is now set up so that lots of apps know Central's API and Central knows what it should send to each of these other apps.

Answer 2

Hi Andy

Point One) It is certainly possible to change the endpoint to which a web service proxy is talking at runtime. I believe it looks something like this...

ws.Endpoint.Address = new System.ServiceModel.EndpointAddress( newurl )

In you case obviously your 'Central App' is going to be invoking the proxy as it sends back the data to your 'requesters/recievers'.

When you requester/reciever is putting in a request, it will be using a proxy to invoke the central app but i guess in this case, it doesn't need to be dynamic (only one 'central app' right?)

Point 2) Not sure what the cleverest way of doing this is. by default of course, the messages you send/recieve from a WCF web service are always XML. If you want the service contract to remain the same, you are going to need a wrapper object to contain the data. I suppose you could try creating an object that has a 'payload' member that can hold your data.

Hope this helps

Michael