Cant get info from FaultExceptions (javascript)

Until now I have used an webservice ASMX which I call from javascript. It has been working fine, but because I needed some control over the serialization, I am trying to switch to DataContracts and WCF. However, I do believe that there is something I have misunderstood, because Im trying to catch faultexceptions from the client code (javascript), but the only errorcode Im receiving is: (tr开发者_如何学Canslated, so might not be accurate)

"The server could not handle the request because of an intern error. You can get more info about the error by activate IncludeExceptionDetailInFaults..."

I have tried to set IncludeExceptionDetailInFauls to true which gives some info, but as far as I understood, the whole point by throwing FaultExceptions is to hide exceptions from the user, and only throw a little info? Im trying with a IErrorHandler, but I have created a simpler example:

The SVC:

[ServiceContract(Namespace = "")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class WcfTest
{
    // To use HTTP GET, add [WebGet] attribute. (Default ResponseFormat is WebMessageFormat.Json)
    // To create an operation that returns XML,
    //    add [WebGet(ResponseFormat=WebMessageFormat.Xml)],
    //    and include the following line in the operation body:
    //        WebOperationContext.Current.OutgoingResponse.ContentType = "text/xml";
    [OperationContract]
    public string DoOk()
    {
        // Add your operation implementation here
        return "Success";
    }
    [OperationContract]
    public string DoFail()
    {
        FaultReason reason = new FaultReason("Fail <- This is good :)");
        throw new FaultException(reason);
        return "Success";
    }
}

---

which is included with a scriptmanager, and called by the following javascript:

<a href="java script:void(0);" onclick="DoOk()">OK</a><br />
        <a href="java script:void(0);" onclick="DoFail()">Fail</a>
        <script>
            function DoOk() {
                WcfTest.DoOk(
                    function (result) {
                        alert("DoOk Success: "+result);
                    },
                    function (result) {
                        alert("DoOk Failed: " + result);
                    })
            }
            function DoFail() {
                WcfTest.DoFail(
                    function (result) {
                        alert("DoFail Success: " + result);
                    },
                    function (result) {
                        alert("DoFail Failed: " + result);
                    })        
            }
        </script>

and a service model:

<system.serviceModel>
  <behaviors>
    <serviceBehaviors>
      <behavior name="WcfTestAspNetAjaxBehavior">
      </behavior>
    </serviceBehaviors>
  <endpointBehaviors>
    <behavior name="WcfTestAspNetAjaxBehavior">
    <enableWebScript />
    </behavior>
  </endpointBehaviors>
  </behaviors>
  <serviceHostingEnvironment aspNetCompatibilityEnabled="true"
  multipleSiteBindingsEnabled="true" />
  <services>
  <service name="WcfTest">
    <endpoint address="" behaviorConfiguration="WcfTestAspNetAjaxBehavior"
    binding="webHttpBinding" contract="WcfTest" />
  </service>
  </services>
</system.serviceModel>

---

Ive also tried to mark the DoFail method with combinations of:

[FaultContract(typeof(FaultException))]  
[FaultContract(typeof(FaultReason))]

Have I misunderstood something? Shouldnt you be able to get exception info back by throwing an FaultException without having to set IncludeExceptionDetailInFaults to true?

---

Useful resources:

• Getting jQuery and WCF to talk
• Error handling with WebHttpBinding for Ajax/JSON

Main steps:

1. Create your own error handler by impelemting IErrorHandler interface
2. Create subclass of WebHttpBehavior and replace the default error handler with you own error handler
3. Plug-in your custom/extended behavior by using a custom ServiceHostFactory or define as behaviorExtension in web.config