1 files changed, 75 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.Core/Messaging/IDataBagFormatter.cs b/src/DotNetOpenAuth.Core/Messaging/IDataBagFormatter.cs
new file mode 100644
index 0000000..fd1c15d
--- /dev/null
+++ b/src/DotNetOpenAuth.Core/Messaging/IDataBagFormatter.cs
@@ -0,0 +1,75 @@
+//-----------------------------------------------------------------------
+// <copyright file="IDataBagFormatter.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.Messaging {
+	using System;
+	using System.Diagnostics.Contracts;
+
+	/// <summary>
+	/// A serializer for <see cref="DataBag"/>-derived types
+	/// </summary>
+	/// <typeparam name="T">The DataBag-derived type that is to be serialized/deserialized.</typeparam>
+	[ContractClass(typeof(IDataBagFormatterContract<>))]
+	internal interface IDataBagFormatter<T> where T : DataBag, new() {
+		/// <summary>
+		/// Serializes the specified message.
+		/// </summary>
+		/// <param name="message">The message to serialize.  Must not be null.</param>
+		/// <returns>A non-null, non-empty value.</returns>
+		string Serialize(T message);
+
+		/// <summary>
+		/// Deserializes a <see cref="DataBag"/>.
+		/// </summary>
+		/// <param name="containingMessage">The message that contains the <see cref="DataBag"/> serialized value.  Must not be nulll.</param>
+		/// <param name="data">The serialized form of the <see cref="DataBag"/> to deserialize.  Must not be null or empty.</param>
+		/// <returns>The deserialized value.  Never null.</returns>
+		T Deserialize(IProtocolMessage containingMessage, string data);
+	}
+
+	/// <summary>
+	/// Contract class for the IDataBagFormatter interface.
+	/// </summary>
+	/// <typeparam name="T">The type of DataBag to serialize.</typeparam>
+	[ContractClassFor(typeof(IDataBagFormatter<>))]
+	internal abstract class IDataBagFormatterContract<T> : IDataBagFormatter<T> where T : DataBag, new() {
+		/// <summary>
+		/// Prevents a default instance of the <see cref="IDataBagFormatterContract&lt;T&gt;"/> class from being created.
+		/// </summary>
+		private IDataBagFormatterContract() {
+		}
+
+		#region IDataBagFormatter<T> Members
+
+		/// <summary>
+		/// Serializes the specified message.
+		/// </summary>
+		/// <param name="message">The message to serialize.  Must not be null.</param>
+		/// <returns>A non-null, non-empty value.</returns>
+		string IDataBagFormatter<T>.Serialize(T message) {
+			Requires.NotNull(message, "message");
+			Contract.Ensures(!String.IsNullOrEmpty(Contract.Result<string>()));
+
+			throw new System.NotImplementedException();
+		}
+
+		/// <summary>
+		/// Deserializes a <see cref="DataBag"/>.
+		/// </summary>
+		/// <param name="containingMessage">The message that contains the <see cref="DataBag"/> serialized value.  Must not be nulll.</param>
+		/// <param name="data">The serialized form of the <see cref="DataBag"/> to deserialize.  Must not be null or empty.</param>
+		/// <returns>The deserialized value.  Never null.</returns>
+		T IDataBagFormatter<T>.Deserialize(IProtocolMessage containingMessage, string data) {
+			Requires.NotNull(containingMessage, "containingMessage");
+			Requires.NotNullOrEmpty(data, "data");
+			Contract.Ensures(Contract.Result<T>() != null);
+
+			throw new System.NotImplementedException();
+		}
+
+		#endregion
+	}
+}
+\ No newline at end of file