x) Add Type Proxy for saving and loading objects we dont have control

ser/XmlFormatter2.cs

@@ -90,6 +90,8 @@ namespace lib
 
 	}
 
+	public record struct TypeProxy( Func<object, string> ser, Func<string, string, object> des );
+
 	public class XmlFormatter2Cfg: Config
 	{
 		public Datastructure datastructure = Datastructure.Graph;
@@ -98,6 +100,8 @@ namespace lib
 
 		public Dictionary<string, List<string>> WLProps = new();
 		public Dictionary<string, List<string>> WLFields= new();
+
+		public Dictionary<Type, TypeProxy> TypeProxy = new();
 	}
 
 	public class XmlFormatter2: IFormatter
@@ -129,9 +133,6 @@ namespace lib
 			Context = new StreamingContext( StreamingContextStates.All );
 		}
 
-
-
-
 		public XmlFormatter2( XmlFormatter2Cfg cfg )
 		{
 			Context = new StreamingContext( StreamingContextStates.All );
@@ -141,8 +142,6 @@ namespace lib
 			log.warn( $"XML serialization is NOT fast" );
 		}
 
-
-
 		#region Deserialize
 		private static FormatterConverter s_conv = new FormatterConverter();
 
@@ -491,7 +490,7 @@ namespace lib
 
 						name = refl.TypeToIdentifier( name );
 
-						if( FilterField( filterFields, doImpls, whitelistFields, childPi as MemberInfo, name ) ) continue;
+						if( FilterField( filterProps, doImpls, whitelistProps, childPi as PropertyInfo, name ) ) continue;
 
 						XmlElement childElem = getNamedChild( allChildren, name );
 
@@ -501,7 +500,20 @@ namespace lib
 
 							object childObj = Deserialize( childElem, childPi, childPi.PropertyType, existingObj );
 
-							childPi.SetValue( obj, childObj );
+							var setMethod = childPi.GetSetMethod();
+
+							if( setMethod != null )
+							{
+								//Object o = Activator.CreateInstance( setMethod.ReflectedType );
+								setMethod.Invoke( obj, new object[]{ childObj } );
+
+								//setMethod.CreateDelegate()
+							}
+							else
+							{
+								childPi.SetValue( obj, childObj );
+							}
+
 						}
 					}
 				}
@@ -540,7 +552,7 @@ namespace lib
 
 			int refInt = refString.Length > 0 ? Convert.ToInt32( refString ) : -1;
 
-			obj = createObject( finalType, refInt, obj );
+			obj = createObject( elem, finalType, refInt, obj );
 
 			return obj;
 		}
@@ -604,14 +616,14 @@ namespace lib
 			return arr;
 		}
 
-		private object createObject( string typename, int refInt, object obj )
+		private object createObject( XmlElement elem, string typename, int refInt, object obj )
 		{
 			Type type = Type.GetType(typename);
 
-			return createObject( type, refInt, obj );
+			return createObject( elem, type, refInt, obj );
 		}
 
-		private object createObject( Type type, int refInt, object existingObj )
+		private object createObject( XmlElement elem, Type type, int refInt, object existingObj )
 		{
 			TypeCode tc = Type.GetTypeCode(type);
 
@@ -621,13 +633,60 @@ namespace lib
 				return m_alreadySerialized[refInt];
 			}
 
+			// FIRST If there is a proxy deserializer, we skip using the existing object.
+
+			var isProxy = elem.HasAttribute( "proxy" );
+
+			if( isProxy )
+			{
+				object obj = null;
+
+				var tryType = type;
+				TypeProxy? proxy = null;
+
+				while( tryType != typeof(object) && obj == null )
+				{
+					//m_cfg.TypeProxy.TryGetValue(  )
+					if( m_cfg.TypeProxy.TryGetValue( tryType, out var newProxy ) )
+					{
+						proxy = newProxy;
+						break;
+					}
+
+					tryType = tryType.BaseType;
+				}
+
+				var proxyVal = elem.GetAttribute( "proxy" );
+
+				if( proxy.HasValue )
+				{
+					obj = proxy.Value.des( type.Name, proxyVal );
+
+					return obj;
+				}
+				else
+				{
+					log.warn( $"Trying to proxy in {elem.Name}, but there is no proxy available.  Falling back to regular hydrate/create" );
+				}
+			}
+
+			// SECOND if we have an existing object there of the same type, replace
+
 			if( existingObj != null )
 			{
 				var existingObjType = existingObj.GetType();
 
-				if( type == existingObjType ) return existingObj;
+				// @@@ GROSS Fix the types so theyre known good.
+				var isSubclass = type.IsSubclassOf( existingObjType ) || existingObjType.IsSubclassOf( type );
+
+				if( isSubclass ) return existingObj;
+
+				// old
+				//if( type == existingObjType ) return existingObj;
 			}
 
+
+			// THIRD create a new object
 			{
 				object obj = null;
 
@@ -647,7 +706,6 @@ namespace lib
 					{
 						log.error( $"Got exception {exInner.Message} trying to make an uninitialized object" );
 					}
-
 				}
 
 				if( obj == null )
@@ -711,13 +769,11 @@ namespace lib
 			return type.FullName; // + ", " + assName;
 		}
 
-
 		public void Serialize( Stream stream, object root )
 		{
 			Serialize( stream, null, root );
 		}
 
-
 		public void Serialize( Stream stream, MemberInfo mi, object root )
 		{
 			//lib.log.info( "Serialize( Stream stream, object root ) {0} {1}", m_rndVal, m_alreadySerialized.Count );
@@ -798,25 +854,14 @@ namespace lib
 				writer.WriteAttributeString( "_.version.", $"{m_cfg.Version}" );
 			}
 
-			/*
-			if( root is IList )
-			{
-				var list = root as IList;
-
-				Type t = root.GetType();
-
-				Type[] genT = t.GetGenericArguments();
-			}
-			*/
-
 			bool first;
 
 			long refInt = m_objectID.GetId(root, out first);
 
+			// @@@@ FIX for proxies. 
 			if( m_cfg.datastructure == Datastructure.Graph )
 			{
 				writer.WriteAttributeString( "ref", refInt.ToString() );
-
 			}
 
 			if( first )
@@ -828,24 +873,15 @@ namespace lib
 
 				Type type = root.GetType();
 
-				//var whitelistProp = type.GetCustomAttribute<WhitelistPropsAttribute>();
-
-				//var useWhitelist = whitelistProp != null;
-
-
 				//*
 				Type typeISerializable = typeof(ISerializable);
 
-				if( root is ISerializable ) //   type.IsSubclassOf( typeISerializable ) )
+				if( root is ISerializable ser )
 				{
-					ISerializable ser = root as ISerializable;
-
 					var serInfo = new SerializationInfo(type, new FormatterConverter());
 
 					ser.GetObjectData( serInfo, Context );
 
-					//var serEnum = ;
-
 					foreach( var serMember in serInfo )
 					{
 						String name = serMember.Name;
@@ -855,11 +891,33 @@ namespace lib
 						Serialize( writer, mi, serMember.Value, name, depth, true );
 					}
 
-					//var sc = new SerializationContext( 
+					return;
-
-					//ser.GetObjectData( 
 				}
-				else
+
+				{
+					var tryType = type;
+					TypeProxy? proxy = null;
+
+					while( tryType != typeof(object) )
+					{
+						if( m_cfg.TypeProxy.TryGetValue( tryType, out var newProxy ) )
+						{
+							proxy = newProxy;
+							break;
+						}
+
+						tryType = tryType.BaseType;
+					}
+
+					if( proxy.HasValue )
+					{
+						var proxyStr = proxy.Value.ser( root );
+						writer.WriteAttributeString( "proxy", proxyStr );
+						return;
+					}
+
+				}
+
 				//*/
 				{
 					bool filterFields, filterProps, doImpls, doFields, doProps;