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1232

answers:

2

How do I remove XML namespaces from an object's XML representation serialized using DataContractSerializer?

That object needs to be serialized to a very simple output XML.

  • Latest & greatest - using .Net 4 beta 2
  • The object will never need to be deserialized.
  • XML should not have any xmlns:... namespace refs
  • Any subtypes of Exception and ISubObject need to be supported.
  • It will be very difficult to change the original object.

Object:

 [Serializable] 
 class MyObj
 {
     string str;
     Exception ex;
     ISubObject subobj;
 }

Need to serialize into:

<xml>
  <str>...</str>
  <ex i:nil="true" />
  <subobj i:type="Abc">
     <AbcProp1>...</AbcProp1>
     <AbcProp2>...</AbcProp2>
  </subobj>
</xml>

I used this code:

private static string ObjectToXmlString(object obj)
{
    if (obj == null) throw new ArgumentNullException("obj");

    var serializer =
        new DataContractSerializer(
            obj.GetType(), null, Int32.MaxValue, false, false, null,
            new AllowAllContractResolver());

    var sb = new StringBuilder();
    using (var xw = XmlWriter.Create(sb, new XmlWriterSettings
    {
        OmitXmlDeclaration = true,
        NamespaceHandling = NamespaceHandling.OmitDuplicates,
        Indent = true
    }))
    {
        serializer.WriteObject(xw, obj);
        xw.Flush();

        return sb.ToString();
    }
}

From this article I adopted a DataContractResolver so that no subtypes have to be declared:

public class AllowAllContractResolver : DataContractResolver
{
    public override bool TryResolveType(Type dataContractType, Type declaredType, DataContractResolver knownTypeResolver, out XmlDictionaryString typeName, out XmlDictionaryString typeNamespace)
    {
        if (!knownTypeResolver.TryResolveType(dataContractType, declaredType, null, out typeName, out typeNamespace))
        {
            var dictionary = new XmlDictionary();
            typeName = dictionary.Add(dataContractType.FullName);
            typeNamespace = dictionary.Add(dataContractType.Assembly.FullName);
        }
        return true;
    }

    public override Type ResolveName(string typeName, string typeNamespace, Type declaredType, DataContractResolver knownTypeResolver)
    {
        return knownTypeResolver.ResolveName(typeName, typeNamespace, declaredType, null) ?? Type.GetType(typeName + ", " + typeNamespace);
    }
}
+1  A: 

You need to mark the classes you want to serialize with:

[DataContract(Namespace="")]

In that case, the data contract serializer will not use any namespace for your serialized objects.

Marc

marc_s
Some of the sub-objects are not under my control and I cannot change them. Is it possible to do it without changing the objects?
Yurik
No, sorry - you cannot remove an existing namespace - you have to be able to specify the namespace on the object itself.
marc_s
That can't be - what about all the system types? MS can't expect all types to be modifiable, there has to be some other way :(
Yurik
No, there doesn't. It doesn't actually make sense for you to be removing namespaces.
John Saunders
So far I have implemented my own XmlWriter (delegating to the real one) that skips namespaces. Not clean, but it works. I suspect that DataContractResolver is capable of solving this for me... Will keep the issue open to see if any new solutions come forth.
Yurik
A: 

Has anyone come up with a clean solution to this? I need to create "xml" for a legacy component in the format: Bob

but DataContractSerializer always adds the namespace?

BlueChippy