RESTful Services in Visual C# 2008

Here’s a problem that had me scratching my head for a while this weekend. How do I create a simple REST service using WCF (Windows Communication Foundation)?

MSDN has a great little tutorial that explains how to code the service and get it running in a standalone application context. However, it fails to address getting the service deployed on an IIS server.

The key point that seems to be missing from the documentation is that no matter what you do with the web.config file, you’re never going to get a configuration that works as a plain-old REST web service. Instead, you have to delete the web service configuration completely from the web.config file, and add the declaration Factory="System.ServiceModel.Activation.WebServiceHostFactory" to the ServiceHost element in the .svc file associated with your service.

Here’s a quick and dirty example:

<%@ ServiceHost Factory="System.ServiceModel.Activation.WebServiceHostFactory"
    Language="C#" Service="Service1" %>
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Web;
using System.Runtime.Serialization;
[ServiceContract]
public class Service1
{
    [OperationContract]
    [WebGet(UriTemplate="{id}")]
    DataType GetData(string id)
    {
        return new DataType(1,"Foo");
    }
}
[DataContract(Name="data",Namespace="http://example.org")]
public class DataType
{
    public DataType(int id, string name)
    {
        this.id = id;
        this.name = name;
    }
    [DataMember]
    int id;
    [DataMember]
    string name;
}

Calling http://host/Service1.svc/123 returns:

<data xmlns="http://example.org" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
    <id>1</id>
    <name>Foo</name>
</data>

That’s actually quite easy really, isn’t it? If only the MSDN docs told you that..