How to add an attribute to an XML node when that node is serialised from a List?

Question

I asked this question yesterday, wondering how to produce XML with attributes using MVCContrib. The answer was to use [XmlAttribute].

Since, I've successfully used [XmlAttribute] to get the following XML:

<?xml version="1.0" encoding="utf-8"?>
<TopTen xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <SectorName>Property - Direct UK</SectorName>
  <PerformanceTo>2011-01-31T00:00:00</PerformanceTo>
  <OrderedShareClassReturns>
    <OrderedShareClassReturn Name="Property L" Performance="11.074980" />
    <OrderedShareClassReturn Name="UK Property Trust I Inc" Performance="10.512610" />
    <OrderedShareClassReturn Name="UK Property Trust I Acc" Performance="10.466310" />
    <OrderedShareClassReturn Name="UK Property Trust R Inc" Performance="9.725650" />
  </OrderedShareClassReturns>
</TopTen>

Now I need to add a second <ShareClassReturns> node to the XML, and I'd like to add an attribute to that element, so the XML becomes:

<?xml version="1.0" encoding="utf-8"?>
<TopTen xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <SectorName>Property - Direct UK</SectorName>
  <PerformanceTo>2011-01-31T00:00:00</PerformanceTo>
  <OrderedShareClassReturns order="top"> // how can I add the "top" & "bottom" attributes?
    <OrderedShareClassReturn Name="Property L" Performance="11.074980" />
    <OrderedShareClassReturn Name="UK Property Trust I Inc" Performance="10.512610" />
    <OrderedShareClassReturn Name="UK Property Trust I Acc" Performance="10.466310" />
    <OrderedShareClassReturn Name="UK Property Trust R Inc" Performance="9.725650" />
  </OrderedShareClassReturnss>
  <OrderedShareClassReturns order="bottom">
    <OrderedShareClassReturn Name="Property L" Performance="0.074980" />
    <OrderedShareClassReturn Name="UK Property Trust I Inc" Performance="1.512610" />
    <OrderedShareClassReturn Name="UK Property Trust I Acc" Performance="2.466310" />
    <OrderedShareClassReturn Name="UK Property Trust R Inc" Performance="3.725650" />
  </OrderedShareClassReturns>
</TopTen>

But I don't know how to do this. The objects that I'm serializing are defined as:

public class TopTen
{

    public string SectorName { get; set; }
    public DateTime PerformanceTo { get; set; }

    public List<OrderedShareClassReturn> OrderedShareClassReturns { get; set; }
}

public class OrderedShareClassReturn
{
    [XmlAttribute]
    public string Name { get; set; }

    [XmlAttribute]
    public decimal Performance { get; set; }
}

So the question is, how can I add that attribute to the <OrderedShareClassReturns> element? Do I need to define a OrderedShareClassReturns as a class that implements a List<OrderedShareClassReturn>, and have a property called order, which has [XmlAttribute]? Or is there an easier way?

Answer 1

To do that you'd need to add another class:

public class ReturnsWrapper {

    [XmlElement("OrderedShareClassReturn")]
    public List<OrderedShareClassReturn> Items { get; set; }

    [XmlAttribute("order")]
    public string Order {get;set;}
}

and have:

public class TopTen
{

    public string SectorName { get; set; }
    public DateTime PerformanceTo { get; set; }
    [XmlElement("OrderedShareClassReturns")]
    public List<ReturnsWrapper> Returns { get; set; }
}