Core.Xml - refactor

src/Umbraco.Core/Xml/XPathNavigatorExtensions.cs

@@ -0,0 +1,30 @@
+using System.Xml.XPath;
+
+namespace Umbraco.Core.Xml
+{
+    /// <summary>
+    /// Provides extensions to XPathNavigator.
+    /// </summary>
+    internal static class XPathNavigatorExtensions
+    {
+        /// <summary>
+        /// Selects a node set, using the specified XPath expression.
+        /// </summary>
+        /// <param name="navigator">A source XPathNavigator.</param>
+        /// <param name="expression">An XPath expression.</param>
+        /// <param name="variables">A set of XPathVariables.</param>
+        /// <returns>An iterator over the nodes matching the specified expression.</returns>
+        public static XPathNodeIterator Select(this XPathNavigator navigator, string expression, params XPathVariable[] variables)
+        {
+            if (variables == null || variables.Length == 0 || variables[0] == null)
+                return navigator.Select(expression);
+
+            var compiled = navigator.Compile(expression);
+            var context = new DynamicContext();
+            foreach (var variable in variables)
+                context.AddVariable(variable.Name, variable.Value);
+            compiled.SetContext(context);
+            return navigator.Select(compiled);
+        }
+    }
+}