All tests passing, with more work done.

1 files changed, 37 insertions, 1 deletions

diff --git a/src/DotNetOAuth/Messaging/Reflection/MessageDescription.cs b/src/DotNetOAuth/Messaging/Reflection/MessageDescription.cs
index ef73a31..6b898bb 100644
--- a/src/DotNetOAuth/Messaging/Reflection/MessageDescription.cs
+++ b/src/DotNetOAuth/Messaging/Reflection/MessageDescription.cs
@@ -9,12 +9,14 @@ namespace DotNetOAuth.Messaging.Reflection {
 	using System.Collections.Generic;

 	using System.Linq;

 	using System.Reflection;

+	using System.Globalization;

 

 	internal class MessageDescription {

+		private static Dictionary<Type, MessageDescription> reflectedMessageTypes = new Dictionary<Type,MessageDescription>();

 		private Type messageType;

 		private Dictionary<string, MessagePart> mapping;

 

-		internal MessageDescription(Type messageType) {

+		private MessageDescription(Type messageType) {

 			if (messageType == null) {

 				throw new ArgumentNullException("messageType");

 			}

@@ -27,6 +29,23 @@ namespace DotNetOAuth.Messaging.Reflection {
 			this.ReflectMessageType();

 		}

 

+		internal static MessageDescription Get(Type messageType) {

+			if (messageType == null) {

+				throw new ArgumentNullException("messageType");

+			}

+

+			MessageDescription result;

+			if (!reflectedMessageTypes.TryGetValue(messageType, out result)) {

+				lock (reflectedMessageTypes) {

+					if (!reflectedMessageTypes.TryGetValue(messageType, out result)) {

+						reflectedMessageTypes[messageType] = result = new MessageDescription(messageType);

+					}

+				}

+			}

+

+			return result;

+		}

+

 		internal Type MessageType {

 			get { return this.messageType; }

 		}

@@ -52,5 +71,22 @@ namespace DotNetOAuth.Messaging.Reflection {
 				currentType = currentType.BaseType;

 			} while (currentType != null);

 		}

+

+		/// <summary>

+		/// Verifies that a given set of keys include all the required parameters

+		/// for this message type or throws an exception.

+		/// </summary>

+		/// <exception cref="ProtocolException">Thrown when required parts of a message are not in <paramref name="keys"/></exception>

+		internal void EnsureRequiredMessagePartsArePresent(IEnumerable<string> keys) {

+			var missingKeys = (from part in Mapping.Values

+							   where part.IsRequired && !keys.Contains(part.Name)

+							   select part.Name).ToArray();

+			if (missingKeys.Length > 0) {

+				throw new ProtocolException(string.Format(CultureInfo.CurrentCulture,

+					MessagingStrings.RequiredParametersMissing,

+					this.messageType.FullName,

+					string.Join(", ", missingKeys)));

+			}

+		}

 	}

 }