Undeclared Namespace in XML (eg: xsi is an undeclared namespace)

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If you XML source publishes invalid XML for some reason ( i.e. it has Xml elements referring to undeclared namespace ) and you try to load this XML in XMLDocument. You would end up getting exception similar to <NameSpace> is an undeclared namespace.

eg:

 <?xml version="1.0" encoding="utf-16"?>

<root>

<Name xsi:nil="true">name1</Name>

<Name xsi:nil="true">name2</Name>

<Name xsi:nil="true">name3</Name>

</root>

Ideally this is an Invalid XML but there is a way to load it in XMLDocument using following code snippet.

 

            XmlDocument doc = new XmlDocument();

            

            NameTable nt = new NameTable();

            XmlNamespaceManager nsmgr = new XmlNamespaceManager(nt);

            nsmgr.AddNamespace("xsi", "https://www.w3.org/2001/XMLSchema-instance");

            XmlParserContext context = new XmlParserContext(null, nsmgr, null, XmlSpace.None);

            XmlReaderSettings xset = new XmlReaderSettings();

            xset.ConformanceLevel = ConformanceLevel.Fragment;

            XmlReader rd = XmlReader.Create(new  StringReader(XMLSource), xset, context); 

              

            doc.Load(rd);

Runeet Vashisht