Send JSON to WCF 3.5 using Ajax

Question

I'm having issues passing JSON to the Weight method. I keep getting HTTP/1.1 415 Cannot process the message because the content type 'application/x-www-form-urlencoded; charset=UTF-8' was not the expected type 'text/xml; charset=utf-8'.

I think I have a problem with either my contract or web.config. All my research turns up empty. I'll be calling this service from a Web Part using jQuery's $.ajax.

Interface:

namespace XXX.SharePoint.WebServices
{
    [ServiceContract]
    public interface ICalculators
    {

        [OperationContract]
        [WebInvoke(Method = "POST",
                   BodyStyle = WebMessageBodyStyle.WrappedRequest,
                   RequestFormat = WebMessageFormat.Json,
                   ResponseFormat = WebMessageFormat.Json
        )]
        Single Weight(Single Width, Single Diameter, Single Size, Single Factor);
    }
}

web.config:

<?xml version="1.0"?>
<configuration>
  <system.serviceModel>
    <services>
      <service behaviorConfiguration="XXX.SharePoint.WebServices.CustomServiceBehaviour"
        name="XXX.SharePoint.WebServices.Calculators">
        <endpoint address=""
                  binding="basicHttpBinding"
                  contract="XXX.SharePoint.WebServices.ICalculators" >
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
        <host>
          <baseAddresses>
            <add baseAddress="http://moss2010/"></add>
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="XXX.SharePoint.WebServices.CustomServiceBehaviour">
          <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
          <serviceMetadata httpGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid
disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
</configuration>

As always, thanks in advance!

Answer 1

Here's a full working example of a WCF service hosted in IIS:

[ServiceContract]
public interface ICalculators
{
    [OperationContract]
    [WebInvoke(Method = "POST",
               BodyStyle = WebMessageBodyStyle.Wrapped,
               RequestFormat = WebMessageFormat.Json,
               ResponseFormat = WebMessageFormat.Json
    )]
    float Weight(float width, float diameter, float size, float factor);
}

public class Calculators : ICalculators
{
    public float Weight(float width, float diameter, float size, float factor)
    {
        return 10f;
    }
}

calculators.svc:

<%@ 
    ServiceHost 
    Language="C#" 
    Debug="true" 
    Service="XXX.SharePoint.WebServices.Calculators" 
    Factory="System.ServiceModel.Activation.WebServiceHostFactory"
    CodeBehind="Calculators.svc.cs" 
%>

web.config:

<system.serviceModel>
    <services>
        <service 
            behaviorConfiguration="XXX.SharePoint.WebServices.CustomServiceBehaviour"
            name="XXX.SharePoint.WebServices.Calculators">
                <endpoint 
                    address=""
                    binding="webHttpBinding"
                    contract="XXX.SharePoint.WebServices.ICalculators"
                />
                <endpoint 
                    address="mex" 
                    binding="mexHttpBinding" 
                    contract="IMetadataExchange" 
                />
        </service>
    </services>
    <behaviors>
        <serviceBehaviors>
            <behavior name="XXX.SharePoint.WebServices.CustomServiceBehaviour">
                <serviceMetadata httpGetEnabled="true"/>
                <serviceDebug includeExceptionDetailInFaults="false"/>
            </behavior>
        </serviceBehaviors>
    </behaviors>
</system.serviceModel>  

Consumption using jQuery in the same ASP.NET application:

$.ajax({
    url: '/calculators.svc/Weight',
    type: 'POST',
    contentType: 'application/json',
    data: JSON.stringify({ Width: 1.2, Diameter: 2.3, Size: 3.4, Factor: 4.5 }),
    success: function (result) {
        alert(result.WeightResult);
    }
});

Notice the usage of webHttpBinding instead of basicHttpBinding (SOAP) in web.config as well as the special WebServiceHostFactory used in the .svc file.