C# – Make a single WCF service support both SOAP, REST and WSDL

crestsoapwcfwsdl

I'm trying to build a C# service in .NET 3.5 that supports both SOAP – and shows the WSDL – and REST.

The SOAP service and WSDL generation was easy enough to do using the ServiceHost and a BasicHttpBinding classes. Got that working and the client was happy.

Because the SOAP calls all used simple parameters, the client developers requested a REST interface for some of the commands. So I changed the ServiceHost class to a WebServiceHost, added necessary WebInvoke and WebGet attributes, added a WebHttpBinding class, and bingo – REST and SOAP were both working out of one service. Way cool, change one interface and both REST and SOAP got the new stuff.

But one problem – the WSDL no longer gets generated. I couldn't browse to http://server/service?wsdl and get the WSDL file. Checking the MSDN docs, that appears to be behavior for a default WebServiceHost.

Question: can I override this behavior so that the WSDL could be obtained? Doesn't have to the same URL as before – it can change – but I just need to have some URL into service to get the WSDL for those SOAP developers.

Best Answer

When you say "added a WebHttpBinding class", it sounds like you are doing a lot of the configuration in code as opposed to in configuration files.

If this is the case, you could try moving the configuration to the configuration file. Then create 2 endpoints for the contract one REST and one SOAP, with 2 different addresses and bindings.

Related Solutions

REST / SOAP endpoints for a WCF service

You can expose the service in two different endpoints. the SOAP one can use the binding that support SOAP e.g. basicHttpBinding, the RESTful one can use the webHttpBinding. I assume your REST service will be in JSON, in that case, you need to configure the two endpoints with the following behaviour configuration

<endpointBehaviors>
  <behavior name="jsonBehavior">
    <enableWebScript/>
  </behavior>
</endpointBehaviors>

An example of endpoint configuration in your scenario is

<services>
  <service name="TestService">
    <endpoint address="soap" binding="basicHttpBinding" contract="ITestService"/>
    <endpoint address="json" binding="webHttpBinding"  behaviorConfiguration="jsonBehavior" contract="ITestService"/>
  </service>
</services>

so, the service will be available at

Apply [WebGet] to the operation contract to make it RESTful. e.g.

public interface ITestService
{
   [OperationContract]
   [WebGet]
   string HelloWorld(string text)
}

Note, if the REST service is not in JSON, parameters of the operations can not contain complex type.

Reply to the post for SOAP and RESTful POX(XML)

For plain old XML as return format, this is an example that would work both for SOAP and XML.

[ServiceContract(Namespace = "http://test")]
public interface ITestService
{
    [OperationContract]
    [WebGet(UriTemplate = "accounts/{id}")]
    Account[] GetAccount(string id);
}

POX behavior for REST Plain Old XML

<behavior name="poxBehavior">
  <webHttp/>
</behavior>

Endpoints

<services>
  <service name="TestService">
    <endpoint address="soap" binding="basicHttpBinding" contract="ITestService"/>
    <endpoint address="xml" binding="webHttpBinding"  behaviorConfiguration="poxBehavior" contract="ITestService"/>
  </service>
</services>

Service will be available at

REST request try it in browser,

http://www.example.com/xml/accounts/A123

SOAP request client endpoint configuration for SOAP service after adding the service reference,

  <client>
    <endpoint address="http://www.example.com/soap" binding="basicHttpBinding"
      contract="ITestService" name="BasicHttpBinding_ITestService" />
  </client>

in C#

TestServiceClient client = new TestServiceClient();
client.GetAccount("A123");

Another way of doing it is to expose two different service contract and each one with specific configuration. This may generate some duplicates at code level, however at the end of the day, you want to make it working.

Rest – Representational state transfer (REST) and Simple Object Access Protocol (SOAP)

Simple explanation about SOAP and REST

SOAP - "Simple Object Access Protocol"

SOAP is a method of transferring messages, or small amounts of information, over the Internet. SOAP messages are formatted in XML and are typically sent using HTTP (hypertext transfer protocol).

Rest - Representational state transfer

Rest is a simple way of sending and receiving data between client and server and it doesn't have very many standards defined. You can send and receive data as JSON, XML or even plain text. It's light weighted compared to SOAP.

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