Getting parameters for web service programmatically?

Question

Hi.

I have a web based system where users should be able to fetch data from a web service by entering the URL and the necessary parameter values.

My problem is, somehow I need to find out the structure of the parameters required in the soap body, which is not necessarily just one or two strings, but could be a whole object tree.

Transmission is not a problem, since it's just plain XML.

How do I do this? Do I need to read the entire WSDL Schema and try to figure this out or is there some easier way? I know .NET can generate code for it, but can I easily find out what classes would have been generated without actually generating it and use reflection to find out what it did?

Does anyone have an idea?

Answer 1

I've never done it, but I believe .net allows you to generate proxies dynamically. You should then be able to reflect the generated classes. I can't see this working well for anything but simple interfaces.

Answer 2

You can use the ServiceDescription Class, which gives you an object model representing your wsdl file.

If you want to try a useful wrapper, chick this post.

Answer 3

Hi,

I see 3 options:

a) Contact the publisher of the web service and ask for documentation and code samples.

b) Use Visual Studio to generate the proxy classes. Then study the generated code to figure out how you could do it yourself without the generated code. You will need to understand how the XMLSerializer class works because this the class that is used to convert generated types to XML.

c) Read the WSDL description to understand the expected parameters and their format.

Hope this helps,

Sly

Answer 4

Try using ChannelFactory. That will let you dynamically call a webservice at run time and create the proxy client. I saw your comment about loading and unloading assemblies. Use the client proxy with reflection and when your done just dispose it.

Answer 5

This problem is difficult to solve for the general case. What if one of the "parameters" of the service is an XML document? What if it's a complex type? How will you generate a UI to permit entry of such things?

You might also look into soapUI.

BTW, creating a new AppDomain to load assemblies into is not difficult. In fact, it's pretty easy.