A Linq extension in the making that is for merging XML Documents.

LinqMerge.CS

using System;
using System.Linq;
using System.Xml.Linq;
public class Foo
{
    public static void Main()
    {
        XDocument test = new XDocument();
        
        //SetValue(test, "thing3", new object[] {"Root", "Blargh", "Node3", "ChildNode"});
        //Console.WriteLine(test.ToString());
        try
        {
        XDocument test2 = new XDocument(new XElement("Root1"));
        SetValue(test2, "thing3", new object[] {new XDocument(new XElement("Root2"))});
        Console.WriteLine(test2.ToString());
        }
        catch(Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
        Console.ReadKey();
        
    }
    
    public static void SetValue (XContainer obj, object value,  params object[] nodes)
    {
         XContainer workingNode =  obj;
         foreach(var node in nodes)
         {
             String nodeName = "notSet";
             if (node is String)
            {
                 nodeName = (String) node;
                  if(workingNode.Element(nodeName) == null)
                 {
                      workingNode.Add(new XElement(nodeName));
                      
                 }
                 workingNode = workingNode.Element(nodeName);
             }
             //here we need to check and see for each node if the current working node contains a matching
             //XContainer
            if (node is XContainer)
            {
               var CurrentContainer = node;
               
               if (((XContainer) node).Parent != null)
               {
                      Console.WriteLine("Had Parent");
               	CurrentContainer = ((XContainer) node).Parent;
               }
               if(CurrentContainer is XDocument)
               {
               	var Document =  (XContainer) CurrentContainer;
               	Console.WriteLine("Working Node is = " + ((XDocument) workingNode).Elements().First().Name.ToString());
                      workingNode = enumerateDescendants(Document);
               }
           }
           
           if(nodes.Last().Equals(nodeName) && value != null)
           {
                 XElement addElement = (XElement) workingNode;
                 addElement.Value = value.ToString();
             }
         }
         
         
    }
    public static XContainer enumerateDescendants(XContainer container)
    {
       XContainer nodeCopy = container;
    	foreach(var element in container.Elements())
    	{
    		if (nodeCopy.Element(element.Name) == null)
    		{
    			nodeCopy.Add(element);
               }
               else if(element.Descendants().Any())
               {
               	
               }
	}
	return nodeCopy;
    }
}

The idea for this will be to allow someone to create, read, or merge XML documents on the fly without having to worry about null reference issues.

Still very early. If you want ot try it out uncomment the 6 lines near the end and try creating a document with something like

var testDocument = new XDocument();
SetValue(testDocument, null, new object() {"Root", "Child"});
SetValue(testDocument, "test Value", new object() {"Root", "Child1"});
Console.WriteLine(testDocument.ToString());