Core.Xml - refactor

src/Umbraco.Core/Umbraco.Core.csproj

@@ -765,6 +765,7 @@
     <Compile Include="Xml\XmlNamespaces.cs" />
     <Compile Include="Xml\XmlNodeListFactory.cs" />
     <Compile Include="Xml\XmlNodeExtensions.cs" />
+    <Compile Include="Xml\XPathNavigatorExtensions.cs" />
     <Compile Include="Xml\XPathVariable.cs" />
   </ItemGroup>
   <ItemGroup>

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);
+        }
+    }
+}

src/Umbraco.Core/Xml/XmlNodeExtensions.cs

@@ -1,24 +1,16 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Xml;
-using System.Xml.XPath;
 
 // source: mvpxml.codeplex.com
 
 namespace Umbraco.Core.Xml
 {
+    /// <summary>
+    /// Provides extensions to XmlNode.
+    /// </summary>
 	internal static class XmlNodeExtensions
 	{
-        static XPathNodeIterator Select(string expression, XPathNavigator source, params XPathVariable[] variables)
-		{
-			var expr = source.Compile(expression);
-			var context = new DynamicContext();
-			foreach (var variable in variables)
-				context.AddVariable(variable.Name, variable.Value);
-			expr.SetContext(context);
-			return source.Select(expr);
-		}
-
         /// <summary>
         /// Selects a list of XmlNode matching an XPath expression.
         /// </summary>
@@ -54,7 +46,7 @@ namespace Umbraco.Core.Xml
             if (variables == null || variables.Length == 0 || variables[0] == null)
                 return source.SelectNodes(expression);
 
-			var iterator = Select(expression, source.CreateNavigator(), variables);
+			var iterator = source.CreateNavigator().Select(expression, variables);
 			return XmlNodeListFactory.CreateNodeList(iterator);
 		}
 

src/Umbraco.Core/XmlHelper.cs

@@ -5,6 +5,7 @@ using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
 using System.Xml;
+using System.Xml.XPath;
 using Umbraco.Core.IO;
 
 namespace Umbraco.Core
@@ -14,6 +15,28 @@ namespace Umbraco.Core
     /// </summary>
     public class XmlHelper
     {
+        /// <summary>
+        /// Gets a value indicating whether a specified string contains only xml whitespace characters.
+        /// </summary>
+        /// <param name="s">The string.</param>
+        /// <returns><c>true</c> if the string contains only xml whitespace characters.</returns>
+        /// <remarks>As per XML 1.1 specs, space, \t, \r and \n.</remarks>
+        public static bool IsXmlWhitespace(string s)
+        {
+            // as per xml 1.1 specs - anything else is significant whitespace
+            s = s.Trim(' ', '\t', '\r', '\n');
+            return s.Length == 0;
+        }
+
+        /// <summary>
+        /// Creates a new <c>XPathDocument</c> from an xml string.
+        /// </summary>
+        /// <param name="xml">The xml string.</param>
+        /// <returns>An <c>XPathDocument</c> created from the xml string.</returns>
+        public static XPathDocument CreateXPathDocument(string xml)
+        {
+            return new XPathDocument(new XmlTextReader(new StringReader(xml)));
+        }
 
         public static string StripDashesInElementOrAttributeNames(string xml)
         {