Get the XPath to an XElement?

Question

I've got an XElement deep within a document. Given the XElement (and XDocument?), is there an extension method to get its full (i.e. absolute, e.g. /root/item/element/child) XPath?

E.g. myXElement.GetXPath()?

EDIT: Okay, looks like I overlooked something very important. Whoops! The index of the element needs to be taken into account. See my last answer for the proposed corrected solution.

Answer 1

The extensions methods:

public static class XExtensions {     /// <summary>     /// Get the absolute XPath to a given XElement     /// (e.g. "/people/person[6]/name[1]/last[1]").     /// </summary>     public static string GetAbsoluteXPath(this XElement element)     {         if (element == null)         {             throw new ArgumentNullException("element");         }          Func<XElement, string> relativeXPath = e =>         {             int index = e.IndexPosition();             string name = e.Name.LocalName;              // If the element is the root, no index is required              return (index == -1) ? "/" + name : string.Format             (                 "/{0}[{1}]",                 name,                  index.ToString()             );         };          var ancestors = from e in element.Ancestors()                         select relativeXPath(e);          return string.Concat(ancestors.Reverse().ToArray()) +                 relativeXPath(element);     }      /// <summary>     /// Get the index of the given XElement relative to its     /// siblings with identical names. If the given element is     /// the root, -1 is returned.     /// </summary>     /// <param name="element">     /// The element to get the index of.     /// </param>     public static int IndexPosition(this XElement element)     {         if (element == null)         {             throw new ArgumentNullException("element");         }          if (element.Parent == null)         {             return -1;         }          int i = 1; // Indexes for nodes start at 1, not 0          foreach (var sibling in element.Parent.Elements(element.Name))         {             if (sibling == element)             {                 return i;             }              i++;         }          throw new InvalidOperationException             ("element has been removed from its parent.");     } } 

And the test:

class Program {     static void Main(string[] args)     {         Program.Process(XDocument.Load(@"C:\test.xml").Root);         Console.Read();     }      static void Process(XElement element)     {         if (!element.HasElements)         {             Console.WriteLine(element.GetAbsoluteXPath());         }         else         {             foreach (XElement child in element.Elements())             {                 Process(child);             }         }     } } 

And sample output:

/tests/test[1]/date[1] /tests/test[1]/time[1]/start[1] /tests/test[1]/time[1]/end[1] /tests/test[1]/facility[1]/name[1] /tests/test[1]/facility[1]/website[1] /tests/test[1]/facility[1]/street[1] /tests/test[1]/facility[1]/state[1] /tests/test[1]/facility[1]/city[1] /tests/test[1]/facility[1]/zip[1] /tests/test[1]/facility[1]/phone[1] /tests/test[1]/info[1] /tests/test[2]/date[1] /tests/test[2]/time[1]/start[1] /tests/test[2]/time[1]/end[1] /tests/test[2]/facility[1]/name[1] /tests/test[2]/facility[1]/website[1] /tests/test[2]/facility[1]/street[1] /tests/test[2]/facility[1]/state[1] /tests/test[2]/facility[1]/city[1] /tests/test[2]/facility[1]/zip[1] /tests/test[2]/facility[1]/phone[1] /tests/test[2]/info[1] 

That should settle this. No?