Fixes InvalidCastExceptions for Identifier and Realm conversions

that can result from receiving a message before the static constructors for those types have executed.

This corrects the regression introduced in v4.0.0.

Fixes #109

1 files changed, 33 insertions, 0 deletions

diff --git a/src/DotNetOpenAuth.Core/Messaging/Reflection/DefaultEncoderAttribute.cs b/src/DotNetOpenAuth.Core/Messaging/Reflection/DefaultEncoderAttribute.cs
new file mode 100644
index 0000000..d827972
--- /dev/null
+++ b/src/DotNetOpenAuth.Core/Messaging/Reflection/DefaultEncoderAttribute.cs
@@ -0,0 +1,33 @@
+//-----------------------------------------------------------------------
+// <copyright file="DefaultEncoderAttribute.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.Messaging.Reflection {
+	using System;
+	using System.Collections.Generic;
+	using System.Linq;
+	using System.Text;
+
+	/// <summary>
+	/// Allows a custom class or struct to be serializable between itself and a string representation.
+	/// </summary>
+	[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, Inherited = false, AllowMultiple = false)]
+	internal sealed class DefaultEncoderAttribute : Attribute {
+		/// <summary>
+		/// Initializes a new instance of the <see cref="DefaultEncoderAttribute"/> class.
+		/// </summary>
+		/// <param name="converterType">The <see cref="IMessagePartEncoder"/> implementing type to use for serializing this type.</param>
+		public DefaultEncoderAttribute(Type converterType) {
+			Requires.NotNull(converterType, "converterType");
+			Requires.True(typeof(IMessagePartEncoder).IsAssignableFrom(converterType), "Argument must be a type that implements {0}.", typeof(IMessagePartEncoder).Name);
+			this.Encoder = (IMessagePartEncoder)Activator.CreateInstance(converterType);
+		}
+
+		/// <summary>
+		/// Gets the default encoder to use for the declaring class.
+		/// </summary>
+		public IMessagePartEncoder Encoder { get; private set; }
+	}
+}