Serialise object to XmlDocument

Question

In order to return useful information in SoapException.Detail for an asmx web service, I took an idea from WCF and created a fault class to contain said useful information. That fault object is then serialised to the required XmlNode of a thrown SoapException.

I'm wondering whether I have the best code to create the XmlDocument - here is my take on it:

var xmlDocument = new XmlDocument();
var serializer = new XmlSerializer(typeof(T));
using (var stream = new MemoryStream())
{
    serializer.Serialize(stream, theObjectContainingUsefulInformation);
    stream.Flush();
    stream.Seek(0, SeekOrigin.Begin);

    xmlDocument.Load(stream);
}

Is there a better way of doing this?

UPDATE: I actually ended up doing the following, because unless you wrap the XML in a <detail> xml element, you get a SoapHeaderException at the client end:

var serialiseToDocument = new XmlDocument();
var serializer = new XmlSerializer(typeof(T));
using (var stream = new MemoryStream())
{
    serializer.Serialize(stream, e.ExceptionContext);
    stream.Flush();
    stream.Seek(0, SeekOrigin.Begin);

    serialiseToDocument.Load(stream);
}

// Remove the xml declaration
serialiseToDocument.RemoveChild(serialiseToDocument.FirstChild);

// Memorise the node we want
var serialisedNode = serialiseToDocument.FirstChild;

// and wrap it in a <detail> element
var rootNode = serialiseToDocument.CreateNode(XmlNodeType.Element, "detail", "");
rootNode.AppendChild(serialisedNode);

UPDATE 2: Given John Saunders excellent answer, I've now started using the following:

private static void SerialiseFaultDetail()
{
    var fault = new ServiceFault
                    {
                        Message = "Exception occurred",
                        ErrorCode = 1010
                    };

    // Serialise to the XML document
    var detailDocument = new XmlDocument();
    var nav = detailDocument.CreateNavigator();

    if (nav != null)
    {
        using (XmlWriter writer = nav.AppendChild())
        {
            var ser = new XmlSerializer(fault.GetType());
            ser.Serialize(writer, fault);
        }
    }

    // Memorise and remove the element we want
    XmlNode infoNode = detailDocument.FirstChild;
    detailDocument.RemoveChild(infoNode);

    // Move into a root <detail> element
    var rootNode = detailDocument.AppendChild(detailDocument.CreateNode(XmlNodeType.Element, "detail", ""));
    rootNode.AppendChild(infoNode);

    Console.WriteLine(detailDocument.OuterXml);
    Console.ReadKey();
}

Answer 1

overall it looks good to me, though I think I'd use strongly typed objects rather than vars in this case.

Also, I don't know that the stream.Seak(0, SeekOrigin.Begin) is really necessary.

Answer 2

EDIT: Creates output inside of detail element

public class MyFault
{
    public int ErrorCode { get; set; }
    public string ErrorMessage { get; set; }
}

public static XmlDocument SerializeFault()
{
    var fault = new MyFault
                    {
                        ErrorCode = 1,
                        ErrorMessage = "This is an error"
                    };

    var faultDocument = new XmlDocument();
    var nav = faultDocument.CreateNavigator();
    using (var writer = nav.AppendChild())
    {
        var ser = new XmlSerializer(fault.GetType());
        ser.Serialize(writer, fault);
    }

    var detailDocument = new XmlDocument();
    var detailElement = detailDocument.CreateElement(
        "exc", 
        SoapException.DetailElementName.Name,
        SoapException.DetailElementName.Namespace);
    detailDocument.AppendChild(detailElement);
    detailElement.AppendChild(
        detailDocument.ImportNode(
            faultDocument.DocumentElement, true));
    return detailDocument;
}