Question

I’m serializing my DTO to XML messages using DataContractSerializer, however I need to support 2 XML formats, they are identical in structure but differ in element naming, so I need to support an alternative set of DataMemeber[Name=””] attributes on my DTO’s. How to solve this without cloning my DTO classes? I need to support both formats at runtime, so preproccessor derectives will not suffice.

Answer 1

Firstly, for fine-grained xml serialization, XmlSerializer is preferable to DataContractSerializer (which is fine as a general purpose serializer, but is hard to take seriously as an xml serializer when it can’t even handle attributes).

Secondly, XmlSerializer has options for this – in particalar, XmlAttributeOverrides. With an XmlAttributeOverrides you can configure the entire setup for your type at runtime, then just pass it in to the XmlSerializer constructor. Important warning: do this once and store the serializer instance, otherwise you will haemorrhage dynamic assemblies.

[XmlRoot("foo")]
public class Foo
{
    [XmlElement("bar")]
    public string Bar { get; set; }
}
class Program
{
    static void Main()
    {
        XmlAttributeOverrides xao = new XmlAttributeOverrides();
        xao.Add(typeof(Foo), new XmlAttributes { XmlRoot =
               new XmlRootAttribute("alpha")});
        xao.Add(typeof(Foo), "Bar", new XmlAttributes { XmlElements = {
               new XmlElementAttribute("beta") } });
        var ser = new XmlSerializer(typeof (Foo), xao);
        XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
        ns.Add("","");
        ser.Serialize(Console.Out, new Foo { Bar = "abc"}, ns);
    }
}

with output:

<alpha>
  <beta>abc</beta>
</alpha>