1 files changed, 81 insertions, 0 deletions
diff --git a/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs b/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs
new file mode 100644
index 0000000..5eae4c7
--- /dev/null
+++ b/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs
@@ -0,0 +1,81 @@
+//-----------------------------------------------------------------------
+// <copyright file="DictionaryXmlReader.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOAuth.Messaging {
+	using System;
+	using System.Collections.Generic;
+	using System.Diagnostics;
+	using System.IO;
+	using System.Linq;
+	using System.Xml;
+	using System.Xml.Linq;
+
+	/// <summary>
+	/// An XmlReader-looking object that actually reads from a dictionary.
+	/// </summary>
+	internal class DictionaryXmlReader {
+		/// <summary>
+		/// Creates an XmlReader that reads data out of a dictionary instead of XML.
+		/// </summary>
+		/// <param name="rootElement">The name of the root XML element.</param>
+		/// <param name="fields">The dictionary to read data from.</param>
+		/// <returns>The XmlReader that will read the data out of the given dictionary.</returns>
+		internal static XmlReader Create(XName rootElement, IDictionary<string, string> fields) {
+			if (fields == null) {
+				throw new ArgumentNullException("fields");
+			}
+
+			return CreateRoundtripReader(rootElement, fields);
+		}
+
+		/// <summary>
+		/// Creates an <see cref="XmlReader"/> that will read values out of a dictionary.
+		/// </summary>
+		/// <param name="rootElement">The surrounding root XML element to generate.</param>
+		/// <param name="fields">The dictionary to list values from.</param>
+		/// <returns>The generated <see cref="XmlReader"/>.</returns>
+		private static XmlReader CreateRoundtripReader(XName rootElement, IDictionary<string, string> fields) {
+			MemoryStream stream = new MemoryStream();
+			XmlWriter writer = XmlWriter.Create(stream);
+			SerializeDictionaryToXml(writer, rootElement, fields);
+			writer.Flush();
+			stream.Seek(0, SeekOrigin.Begin);
+
+			// For debugging purposes.
+			StreamReader sr = new StreamReader(stream);
+			Trace.WriteLine(sr.ReadToEnd());
+			stream.Seek(0, SeekOrigin.Begin);
+
+			return XmlReader.Create(stream);
+		}
+
+		/// <summary>
+		/// Writes out the values in a dictionary as XML.
+		/// </summary>
+		/// <param name="writer">The <see cref="XmlWriter"/> to write out the XML to.</param>
+		/// <param name="rootElement">The name of the root element to use to surround the dictionary values.</param>
+		/// <param name="fields">The dictionary with values to serialize.</param>
+		private static void SerializeDictionaryToXml(XmlWriter writer, XName rootElement, IDictionary<string, string> fields) {
+			if (writer == null) {
+				throw new ArgumentNullException("writer");
+			}
+			if (fields == null) {
+				throw new ArgumentNullException("fields");
+			}
+
+			writer.WriteStartElement(rootElement.LocalName, rootElement.NamespaceName);
+
+			// The elements must be serialized in alphabetical order so the DataContractSerializer will see them.
+			foreach (var pair in fields.OrderBy(pair => pair.Key, StringComparer.Ordinal)) {
+				writer.WriteStartElement(pair.Key, rootElement.NamespaceName);
+				writer.WriteValue(pair.Value);
+				writer.WriteEndElement();
+			}
+
+			writer.WriteEndElement();
+		}
+	}
+}