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Now that WebServiceHost2Factory is dead, how do I return error text from a WCF rest service?

Tags:

rest

c#

.net

wcf

I've seen several references to WebServiceHost2Factory as the class to use to effectively handle errors in WCF Rest services. Apparently with that class, I just had to throw a WebProtocolException and the body of the response would contain pertinent information.

That class seems to have fallen out of favor now. Is there a replacement somewhere in the .NET 4 stack?

I'm trying to figure out how to return error text in the body of a response to a POST operation, if something went wrong. The key question is below next to all the *'s

Example:

[Description("Performs a full enroll and activation of the member into the Loyalty program")]
[OperationContract]
[WebInvoke(Method = "POST", UriTemplate = "/fullenroll/{clientDeviceId}",
    BodyStyle = WebMessageBodyStyle.Bare,
    RequestFormat = WebMessageFormat.Json,
    ResponseFormat = WebMessageFormat.Json)]
public MemberInfo FullEnroll(string clientDeviceId, FullEnrollmentRequest request)
{
    Log.DebugFormat("FullEnroll. ClientDeviceId: {0}, Request:{1}", clientDeviceId, request);
    MemberInfo ret = null;
    try
    {
      //Do stuff
    }
    catch (FaultException<LoyaltyException> fex)
    {
        Log.ErrorFormat("[loyalty full enroll] Caught faultexception attempting to full enroll. Message: {0}, Reason: {1}, Data: {2}", fex.Message, fex.Reason, fex.Detail.ExceptionMessage);
        HandleException("FullEnroll", fex, fex.Detail.ExceptionMessage);
    }
    catch (Exception e)
    {
        Log.ErrorFormat(
            "[loyalty full enroll] Caught exception attempting to full enroll. Exception: {0}", e);
        HandleException("FullEnroll", e);
    }
    return ret;
}


/// <summary>
/// Deals w/ the response when Exceptions are thrown
/// </summary>
private static Exception HandleException(string function, Exception e, string statusMessage = null)
{
    // Set the return context, handle the error
    if (WebOperationContext.Current != null)
    {
        var response = WebOperationContext.Current.OutgoingResponse;

        // Set the error code based on the Exception
        var errorNum = 500;
        if (e is HttpException)
            errorNum = ((HttpException)e).ErrorCode;

        response.StatusCode = (HttpStatusCode) Enum.Parse(typeof (HttpStatusCode), errorNum.ToString());
        response.StatusDescription = statusMessage;
        // ****************************************************
        // How can I return this as the body of the Web Method?
        // ****************************************************
        WebOperationContext.Current.CreateTextResponse(statusMessage);
    }

    return (e is HttpException) ? e : new HttpException(500, string.Format("{0} caught an exception", function));
}
like image 857
tobyb Avatar asked Oct 05 '22 17:10

tobyb


1 Answers

This answer seems to suggest using the following,

HttpContext.Current.Response.Write(statusMessage);

Edit - As tobyb mentioned in the comments, AspNetCompatibility is required.

Here's how to turn it on:

<system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true">
    <!--  ...  -->
</system.serviceModel>
like image 150
Jesse Avatar answered Oct 21 '22 11:10

Jesse