How to create an XML document from a .NET object?

Question

I have the following variable that accepts a file name:

var xtr = new XmlTextReader(xmlFileName) { WhitespaceHandling = WhitespaceHandling.None };
var xd = new XmlDocument();
xd.Load(xtr);

I would like to change it so that I can pass in an object. I don't want to have to serialize the object to file first.

Is this possible?

Update:

My original intentions were to take an xml document, merge some xslt (stored in a file), then output and return html... like this:

public string TransformXml(string xmlFileName, string xslFileName)
{
     var xtr = new XmlTextReader(xmlFileName) { WhitespaceHandling = WhitespaceHandling.None };
     var xd = new XmlDocument();
     xd.Load(xtr);

     var xslt = new System.Xml.Xsl.XslCompiledTransform();
     xslt.Load(xslFileName);
     var stm = new MemoryStream();
     xslt.Transform(xd, null, stm);
     stm.Position = 1;
     var sr = new StreamReader(stm);
     xtr.Close();
     return sr.ReadToEnd();
}

In the above code I am reading in the xml from a file. Now what I would like to do is just work with the object, before it was serialized to the file.

So let me illustrate my problem using code

public string TransformXMLFromObject(myObjType myobj , string xsltFileName)
{
     // Notice the xslt stays the same.
     // Its in these next few lines that I can't figure out how to load the xml document (xd) from an object, and not from a file....

     var xtr = new XmlTextReader(xmlFileName) { WhitespaceHandling = WhitespaceHandling.None };
     var xd = new XmlDocument();
     xd.Load(xtr);
}

Answer 1

You want to turn an arbitrary .NET object into a serialized XML string? Nothing simpler than that!! :-)

public string SerializeToXml(object input)
{
   XmlSerializer ser = new XmlSerializer(input.GetType(), "http://schemas.yournamespace.com");
   string result = string.Empty;

   using(MemoryStream memStm = new MemoryStream())
   {
     ser.Serialize(memStm, input);

     memStm.Position = 0;
     result = new StreamReader(memStm).ReadToEnd();
   } 

   return result;
} 

That should to it :-) Of course you might want to make the default XML namespace configurable as a parameter, too.

Or do you want to be able to create an XmlDocument on top of an existing object?

public XmlDocument SerializeToXmlDocument(object input)
{
   XmlSerializer ser = new XmlSerializer(input.GetType(), "http://schemas.yournamespace.com");

   XmlDocument xd = null;

   using(MemoryStream memStm = new MemoryStream())
   {
     ser.Serialize(memStm, input);

     memStm.Position = 0;

     XmlReaderSettings settings = new XmlReaderSettings();
     settings.IgnoreWhitespace = true;

     using(var xtr = XmlReader.Create(memStm, settings))
     {  
        xd = new XmlDocument();
        xd.Load(xtr);
     }
   }

   return xd;
}

Answer 2

You can serialize directly into the XmlDocument:

XmlDocument doc = new XmlDocument();
XPathNavigator nav = doc.CreateNavigator();
using (XmlWriter w = nav.AppendChild())
{
    XmlSerializer ser = new XmlSerializer(typeof(MyType));
    ser.Serialize(w, myObject);
}