How to remove xmlns attribute with .NET XML API

Question

XmlElement.Attributes.Remove* methods are working fine for arbitrary attributes resulting in the removed attributes being removed from XmlDocument.OuterXml property. Xmlns attribute however is different. Here is an example:

XmlDocument doc = new XmlDocument();
doc.InnerXml = @"<Element1 attr1=""value1"" xmlns=""http://mynamespace.com/"" attr2=""value2""/>";
doc.DocumentElement.Attributes.RemoveNamedItem("attr2");
Console.WriteLine("xmlns attr before removal={0}", doc.DocumentElement.Attributes["xmlns"]);
doc.DocumentElement.Attributes.RemoveNamedItem("xmlns");
Console.WriteLine("xmlns attr after removal={0}", doc.DocumentElement.Attributes["xmlns"]);

The resulting output is

xmlns attr before removal=System.Xml.XmlAttribute
xmlns attr after removal=
<Element1 attr1="value1" xmlns="http://mynamespace.com/" />

The attribute seems to be removed from the Attributes collection, but it is not removed from XmlDocument.OuterXml. I guess it is because of the special meaning of this attribute.

The question is how to remove the xmlns attribute using .NET XML API. Obviously I can just remove the attribute from a String representation of this, but I wonder if it is possible to do the same thing using the API.

@Edit: I'm talking about .NET 2.0.

Solution 1

.NET DOM API doesn't support modifying element's namespace which is what you are essentially trying to do. So, in order to solve your problem you have to construct a new document one way or another. You can use the same .NET DOM API and create a new element without specifying its namespace. Alternatively, you can create an XSLT stylesheet that transforms your original "namespaced" document to a new one in which the elements will be not namespace-qualified.

Solution 2

Many thanks to Ali Shah, this thread solved my problem perfectly! here's a C# conversion:

var dom = new XmlDocument();
        dom.Load("C:/ExampleFITrade.xml));
        var loaded = new XDocument();
        if (dom.DocumentElement != null)
            if( dom.DocumentElement.NamespaceURI != String.Empty)
            {
                dom.LoadXml(dom.OuterXml.Replace(dom.DocumentElement.NamespaceURI, ""));
                dom.DocumentElement.RemoveAllAttributes();
                loaded = XDocument.Parse(dom.OuterXml);
            }

Solution 3

Wasn't this supposed to remove namespaces?

XmlNamespaceManager mgr = new XmlNamespaceManager("xmlnametable");
mgr.RemoveNamespace("prefix", "uri");

But anyway on a tangent here, the XElement, XDocument and XNameSpace classes from System.Xml.Linq namespace (.Net 3.0) are a better lot than the old XmlDocument model. Give it a go. I am addicted.

Solution 4

I saw the various options in this thread and come to solve my own solution for removing xmlns attributes in xml. This is working properly and has no issues:

'Remove the Equifax / Transunian / Experian root node attribute that have xmlns and load xml without xmlns attributes.
If objXMLDom.DocumentElement.NamespaceURI <> String.Empty Then
  objXMLDom.LoadXml(objXMLDom.OuterXml.Replace(objXMLDom.DocumentElement.NamespaceURI, ""))
  objXMLDom.DocumentElement.RemoveAllAttributes()
  ResponseXML = objXMLDom.OuterXml
End If

There is no need to do anything else to remove xmlns from xml.

Solution 5

public static string RemoveXmlns(string xml)
{
    //Prepare a reader
    StringReader stringReader = new StringReader(xml);
    XmlTextReader xmlReader = new XmlTextReader(stringReader);
    xmlReader.Namespaces = false; //A trick to handle special xmlns attributes as regular
    //Build DOM
    XmlDocument xmlDocument = new XmlDocument();
    xmlDocument.Load(xmlReader);
    //Do the job
    xmlDocument.DocumentElement.RemoveAttribute("xmlns"); 
    //Prepare a writer
    StringWriter stringWriter = new StringWriter();
    XmlTextWriter xmlWriter = new XmlTextWriter(stringWriter);
    //Optional: Make an output nice ;)
    xmlWriter.Formatting = Formatting.Indented;
    xmlWriter.IndentChar = ' ';
    xmlWriter.Indentation = 2;
    //Build output
    xmlDocument.Save(xmlWriter);
    return stringWriter.ToString();
}

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Comments

[axk]

I've tried this, but haven't been able to figure out how to remove a namespace with this class.

[axk]

Thanks for the suggestion. Will definitely give it a try.

[axk]

I'm not sure, but as long as there is no positive answer, I believe it is true.

[Rob]

A little narrative description of your proposed answer would be helpful.