1 files changed, 17 insertions, 47 deletions

diff --git a/csharp/src/ProtocolBuffers/FieldAccess/SingleFieldAccessor.cs b/csharp/src/ProtocolBuffers/FieldAccess/SingleFieldAccessor.cs
index 7a8f726e..cdc89e8d 100644
--- a/csharp/src/ProtocolBuffers/FieldAccess/SingleFieldAccessor.cs
+++ b/csharp/src/ProtocolBuffers/FieldAccess/SingleFieldAccessor.cs
@@ -39,76 +39,46 @@ namespace Google.Protobuf.FieldAccess
     /// <summary>
     /// Accessor for single fields.
     /// </summary>
-    /// <typeparam name="T">The type of message containing the field.</typeparam>
-    internal sealed class SingleFieldAccessor<T> : FieldAccessorBase<T> where T : IMessage<T>
+    internal sealed class SingleFieldAccessor : FieldAccessorBase
     {
         // All the work here is actually done in the constructor - it creates the appropriate delegates.
         // There are various cases to consider, based on the property type (message, string/bytes, or "genuine" primitive)
         // and proto2 vs proto3 for non-message types, as proto3 doesn't support "full" presence detection or default
         // values.
 
-        private readonly Action<T, object> setValueDelegate;
-        private readonly Action<T> clearDelegate;
-        private readonly Func<T, bool> hasValueDelegate;
+        private readonly Action<object, object> setValueDelegate;
+        private readonly Action<object> clearDelegate;
 
-        internal SingleFieldAccessor(FieldDescriptor descriptor, string name, bool supportsFieldPresence) : base(name)
+        internal SingleFieldAccessor(Type type, string propertyName, FieldDescriptor descriptor) : base(type, propertyName, descriptor)
         {
-            PropertyInfo property = typeof(T).GetProperty(name);
+            PropertyInfo property = type.GetProperty(propertyName);
             // We know there *is* such a property, or the base class constructor would have thrown. We should be able to write
             // to it though.
             if (!property.CanWrite)
             {
                 throw new ArgumentException("Not all required properties/methods available");
             }
-            setValueDelegate = ReflectionUtil.CreateDowncastDelegate<T>(property.GetSetMethod());
+            setValueDelegate = ReflectionUtil.CreateActionObjectObject(property.GetSetMethod());
 
             var clrType = property.PropertyType;
+            
+            // TODO: What should clear on a oneof member do? Clear the oneof?
 
-            if (typeof(IMessage).IsAssignableFrom(clrType))
-            {
-                // Message types are simple - we only need to detect nullity.
-                clearDelegate = message => SetValue(message, null);
-                hasValueDelegate = message => GetValue(message) == null;
-            }
-
-            if (supportsFieldPresence)
-            {
-                // Proto2: we expect a HasFoo property and a ClearFoo method.
-                // For strings and byte arrays, setting the property to null would have the equivalent effect,
-                // but we generate the method for consistency, which makes this simpler.
-                PropertyInfo hasProperty = typeof(T).GetProperty("Has" + name);
-                MethodInfo clearMethod = typeof(T).GetMethod("Clear" + name);
-                if (hasProperty == null || clearMethod == null || !hasProperty.CanRead)
-                {
-                    throw new ArgumentException("Not all required properties/methods available");
-                }
-                hasValueDelegate = ReflectionUtil.CreateDelegateFunc<T, bool>(hasProperty.GetGetMethod());
-                clearDelegate = ReflectionUtil.CreateDelegateAction<T>(clearMethod);
-            }
-            else
-            {
-                /*
-                // TODO(jonskeet): Reimplement. We need a better way of working out default values.
-                // Proto3: for field detection, we just need the default value of the field (0, "", byte[0] etc)
-                // To clear a field, we set the value to that default.
-                object defaultValue = descriptor.DefaultValue;
-                hasValueDelegate = message => GetValue(message).Equals(defaultValue);
-                clearDelegate = message => SetValue(message, defaultValue);
-                */
-            }
-        }
-
-        public override bool HasValue(T message)
-        {
-            return hasValueDelegate(message);
+            // TODO: Validate that this is a reasonable single field? (Should be a value type, a message type, or string/ByteString.)
+            object defaultValue =
+                typeof(IMessage).IsAssignableFrom(clrType) ? null
+                : clrType == typeof(string) ? ""
+                : clrType == typeof(ByteString) ? ByteString.Empty
+                : Activator.CreateInstance(clrType);
+            clearDelegate = message => SetValue(message, defaultValue);
         }
 
-        public override void Clear(T message)
+        public override void Clear(object message)
         {
             clearDelegate(message);
         }
 
-        public override void SetValue(T message, object value)
+        public override void SetValue(object message, object value)
         {
             setValueDelegate(message, value);
         }