1 files changed, 62 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth/OAuth/ChannelElements/UriOrOobEncoder.cs b/src/DotNetOpenAuth/OAuth/ChannelElements/UriOrOobEncoder.cs
new file mode 100644
index 0000000..9652e24
--- /dev/null
+++ b/src/DotNetOpenAuth/OAuth/ChannelElements/UriOrOobEncoder.cs
@@ -0,0 +1,62 @@
+//-----------------------------------------------------------------------
+// <copyright file="UriOrOobEncoder.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OAuth.ChannelElements {
+	using System;
+	using System.Collections.Generic;
+	using System.Linq;
+	using System.Text;
+	using DotNetOpenAuth.Messaging.Reflection;
+
+	/// <summary>
+	/// An URI encoder that translates null <see cref="Uri"/> references as "oob" 
+	/// instead of an empty/missing argument.
+	/// </summary>
+	internal class UriOrOobEncoder : IMessagePartEncoder {
+		/// <summary>
+		/// The string constant "oob", used to indicate an out-of-band configuration.
+		/// </summary>
+		private const string OutOfBandConfiguration = "oob";
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="UriOrOobEncoder"/> class.
+		/// </summary>
+		internal UriOrOobEncoder() {
+		}
+
+		#region IMessagePartEncoder Members
+
+		/// <summary>
+		/// Encodes the specified value.
+		/// </summary>
+		/// <param name="value">The value.  Guaranteed to never be null.</param>
+		/// <returns>
+		/// The <paramref name="value"/> in string form, ready for message transport.
+		/// </returns>
+		public string Encode(object value) {
+			Uri uriValue = (Uri)value;
+			return uriValue != null ? uriValue.AbsoluteUri : OutOfBandConfiguration;
+		}
+
+		/// <summary>
+		/// Decodes the specified value.
+		/// </summary>
+		/// <param name="value">The string value carried by the transport.  Guaranteed to never be null, although it may be empty.</param>
+		/// <returns>
+		/// The deserialized form of the given string.
+		/// </returns>
+		/// <exception cref="FormatException">Thrown when the string value given cannot be decoded into the required object type.</exception>
+		public object Decode(string value) {
+			if (string.Equals(value, OutOfBandConfiguration, StringComparison.Ordinal)) {
+				return null;
+			} else {
+				return new Uri(value, UriKind.Absolute);
+			}
+		}
+
+		#endregion
+	}
+}