Serialize xsd:anyType on a client proxy

gistfile1.cs

/*
When you have a XML schema with a xsd:anyType element, eg:

  <complexType name="Example">
    <sequence>
      <element name="DateTime" type="dateTime" minOccurs="1" maxOccurs="1" />
      <element name="Value" type="string" minOccurs="1" maxOccurs="1" />
      <element name="Details" type="anyType" minOccurs="0" maxOccurs="1" />
    </sequence>
  </complexType>

And generate a service proxy, you'll get a class with something alike:

    ...
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(Namespace="http://example.com")]
    public partial class Example: object, System.ComponentModel.INotifyPropertyChanged
    {
        [System.Xml.Serialization.XmlElementAttribute(Order=0)]
        public System.DateTime DateTime { get; set; }

        [System.Xml.Serialization.XmlElementAttribute(Order=1)]
        public string Value { get; set; }

        [System.Xml.Serialization.XmlElementAttribute(Order=2)]
        public object Details { get; set; }
    }

Notice that the Details property type is-a object. How will we set this property value?
In my particular case, I want to set it to an arbitrary XML fragment; it turns out we
have to manually fiddle with the generated code by doing the following:

  1. create a new class to represent the Details, eg: ExampleDetails.
  2. change the Example.Details property type, eg: to ExampleDetails.

In this gist I'll show the ExampleDetails class.
*/

...
using System.Runtime.Serialization;
using System.Xml;
using System.Xml.Serialization;

public class ExampleDetails : IXmlSerializable
{
	private readonly XmlNode[] _details;

	public MetricDetails()
	{
	}

	public MetricDetails(XmlNode[] details)
	{
		_details = details;
	}

	public XmlSchema GetSchema()
	{
		return null;
	}

	public void ReadXml(XmlReader reader)
	{
		throw new NotImplementedException();
	}

	public void WriteXml(XmlWriter writer)
	{
		XmlSerializableServices.WriteNodes(writer, _details);
	}
}


//
// Create ExampleDetails with something like:

private static ExampleDetails CreateExampleDetails(IEnumerable<XElement> elements)
{
	var doc = new XmlDocument();

	var details = elements.Select(element =>
					{
						var node = doc.CreateElement(element.Name.LocalName);
						node.AppendChild(doc.CreateTextNode(element.Value));
						return node;
					}
	).ToArray();

	return new ExampleDetails(details);
}