Exception: The XPath expression evaluated to unexpected type System.Xml.Linq.XAttribute

Question

I've an XML file like below:

<Employees>
  <Employee Id="ABC001">
    <Name>Prasad 1</Name>
    <Mobile>9986730630</Mobile>
    <Address Type="Perminant">
      <City>City1</City>
      <Country>India</Country>
    </Address>
    <Address Type="Temporary">
      <City>City2</City>
      <Country>India</Country>
    </Address>
  </Employee>

Now I want get all Address Type's.

I tried like below using XPath and I'm getting exception.

var xPathString = @"//Employee/Address/@Type";
doc.XPathSelectElements(xPathString); // doc is XDocument.Load("xml file Path")

Exception: The XPath expression evaluated to unexpected type System.Xml.Linq.XAttribute.

Is there any issue with my XPath?

Answer 1

Your XPath is fine (although you might want it to be more selective), but you have to adjust how you evaluate it...

XPathSelectElement() , as its name implies, should only be used to select elements.

XPathEvaluate() is more general and can be used for attributes. You can enumerate over the results, or grab the first:

var type = ((IEnumerable<object>)doc.XPathEvaluate("//Employee/Address/@Type"))
                                    .OfType<XAttribute>()
                                    .Single()
                                    .Value;

Answer 2

Another option would be:

var addresses = doc.XPathSelectElements("//Employee/Address"));
foreach(var address in addresses) {
    var addrType = address.Attribute("Type").Value;
}

Answer 3

Expanding on kjhughes's answer, I've tended to create an XElement class extension for this so that I can simply call element.XPathSelectAttribute(), which makes my calling code look a great deal clearner.

public static class XElementExtensions
{
    public static XAttribute XPathSelectAttribute(this XElement element, string xPath)
    {
        return ((IEnumerable<object>)element.XPathEvaluate(xPath)).OfType<XAttribute>().First();
    }
}