Question

I’m working with an existing xsd which looks something like this (shortened for brevity):

<?xml version="1.0" encoding="utf-8"?>
<xs:schema targetNamespace="http://www.mycompany.com/Widgets"
    xmlns="http://www.mycompany.com/Widgets"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    elementFormDefault="qualified">
  <xs:element name="Widget" type="WidgetDefinition" />
  <xs:complexType name="WidgetDefinition">
    <xs:sequence>
        <xs:element name="name" type="xs:string"/>
    </xs:sequence>
  </xs:complexType> 
</xs:schema>

When you run this through xsd.exe, you get a class definition like:

[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.3038")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(Namespace="http://www.mycompany.com/Widgets")]
[System.Xml.Serialization.XmlRootAttribute("Widget", Namespace="http://www.mycompany.com/Widgets", IsNullable=false)]
public partial class WidgetDefinition {
    private string nameField;

    public string Name {
      get {
          return this.nameField;
      }
      set {
          this.nameField = value;
      }
    }
}

Fast forward … I’m using HTTPClient to POST to a REST service. The code here is pretty straightforward.

var widget = new WidgetDefinition();
// do something here to hydrate widget
var httpClient = new HttpClient();
return httpClient.PostAsync<WidgetDefinition>(
    uri, terminatedCall, new XmlMediaTypeFormatter());

On the receiving end, I want to take the request payload and convert it back to a WidgetDefinition object. If you examine the request content using:

request.Content.ReadAsStringAsync().Result

The xml looks like:

<WidgetDefinition xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns=\"http://schemas.datacontract.org/2004/07/\">
...

Based on the XmlTypeAttribute and XmlRootAttribute attributes on the generated WidgetDefinition class, I expect this to look like:

<Widget xmlns:i=\"http://www.mycompany.com/Widgets\">
...

It appears that the XmlTypeAttribute and XmlRootAttribute attributes are ignored when the serialization is happening on the sending side.

Any clue what could be causing this?

EDIT: If I serialize this manually using XmlSerializer, it obeys the serialization attributes on the WidgetDefinition class. I think my issue has to do with the formatter being passed to the PostAsync call.

Answer 1

From this xmlns=\"http://schemas.datacontract.org/2004/07/\" it appears that your REST service is configured to use DataContractSerializer (the default in a WCF service) and not XmlSerializer.

You can configure your service to use XmlSerializer instead which should at least get you further along:

http://msdn.microsoft.com/en-us/library/ms733901.aspx