Question

I am trying to find a node by the name attribute value.

Here is a sample of the xml document:

<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE kfx:XMLRELEASE SYSTEM "K000A004.dtd">
<kfx:XMLRELEASE xmlns:kfx="http://www.kofax.com/dtd/">
  <kfx:KOFAXXML>
    <kfx:BATCHCLASS ID="00000008" NAME="CertficateOfLiability">
      <kfx:DOCUMENTS>
        <kfx:DOCUMENT DOCID="00000006" DOCUMENTCLASSNAME="COL">
          <kfx:DOCUMENTDATA>
            <kfx:DOCUMENTFIELD NAME="Producer Name" VALUE="Howalt+McDowell Insurance" />
           ...
           ....

Here is my attempted expression:

 var xml = XDocument.Load(new StreamReader("C:\\Users\\Matthew_cox\\Documents\\test.xml"));
 XNamespace ns = "http://www.kofax.com/dtd/";
 XmlNamespaceManager nsm = new XmlNamespaceManager(xml.CreateNavigator().NameTable);
 nsm.AddNamespace("kfx", ns.NamespaceName);

 var docs = xml.Descendants(ns + "DOCUMENT");
 foreach(var doc in docs)
 {
      doc.XPathSelectElement("/DOCUMENTDATA/DOCUMENTFIELD/[@name='Producer Name']", nsm); //this line produces this exception: Expression must evaluate to a node-set.
 }

Answer 1

XML is case-sensitive. In provided XML kfx:DOCUMENTFIELD has NAME attribute. Also your XPath doesn’t have reference to namespace.

Try this XPath:

kfx:DOCUMENTDATA/kfx:DOCUMENTFIELD[@NAME = 'Producer Name']