Split out XmlSer stuff. Fix behaviour

.editorconfig

@@ -80,8 +80,6 @@ dotnet_analyzer_diagnostic.severity = none
 # .NET Style Rules
 # https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/language-rules#net-style-rules
 [*.{cs,csx,cake,vb,vbx}]
-indent_style = tab
-
 # "this." and "Me." qualifiers
 dotnet_style_qualification_for_field = false:none
 dotnet_style_qualification_for_property = false:none

lib/CodeGen.cs

@@ -24,7 +24,7 @@ public record CodeGenConfig : imm.Recorded<CodeGenConfig>
     public ImmutableDictionary<string, ImmutableList<string>> WLFields { get; init; } = ImmutableDictionary<string, ImmutableList<string>>.Empty;
 
     // Default member types to process
-    public lib.Types TypesDefault { get; init; } = lib.Types.Fields | lib.Types.Props;
+    public ser.Types TypesDefault { get; init; } = ser.Types.Fields | ser.Types.Props;
 
     // How to handle backing fields (might be less relevant for code gen)
     public BackingFieldNaming Naming { get; init; } = BackingFieldNaming.Regular;
@@ -62,9 +62,9 @@ public class TypeStructureAnalyzer
     private TypeStructureInfo BuildTypeInfo(Type type)
     {
         var members = new List<GenMemberMeta>();
-        var typesTodo = type.GetCustomAttribute<lib.Ser>(true)?.Types ?? _cfg.TypesDefault;
-        bool doFields = typesTodo.HasFlag(lib.Types.Fields);
-        bool doProps = typesTodo.HasFlag(lib.Types.Props);
+        var typesTodo = type.GetCustomAttribute<ser.Ser>(true)?.Types ?? _cfg.TypesDefault;
+        bool doFields = typesTodo.HasFlag(ser.Types.Fields);
+        bool doProps = typesTodo.HasFlag(ser.Types.Props);
 
         // Track processed names to avoid duplicates (e.g., field + prop)
         var processedNames = new HashSet<string>();
@@ -156,8 +156,8 @@ public class TypeStructureAnalyzer
         }
 
         return (
-            actualMi.GetCustomAttribute<lib.Do>() != null,
-            actualMi.GetCustomAttribute<lib.Dont>() != null,
+            actualMi.GetCustomAttribute<ser.Do>() != null,
+            actualMi.GetCustomAttribute<ser.Dont>() != null,
             propName
         );
     }

lib/XmlFormatter2.cs

@@ -39,60 +39,6 @@ using System.Net.Sockets;
 namespace lib
 {
 
-	public interface I_Serialize
-	{
-		void OnSerialize() {}
-		object OnDeserialize( object enclosing ) => this;
-	}
-
-
-	[Flags]
-	public enum Types
-	{
-		Fields = 0b_0001,
-		Props = 0b_0010,
-		Implied = 0b_0100,
-		Explicit = 0b_1000,
-
-
-		None = 0b_0000,
-		Default = Fields,
-		All = Fields | Props,
-	}
-
-	public class Ser : Attribute
-	{
-		public Types Types { get; set; } = Types.Default;
-	}
-
-	public class Do : Attribute
-	{
-	}
-
-	public class Dont : Attribute
-	{
-	}
-
-	public class ChildAttribute : Attribute
-	{
-		public string[] Values { get; private set; }
-
-		public ChildAttribute( params string[] values )
-		{
-			this.Values = values;
-		}
-	}
-
-	public class ChildFieldsAttribute : ChildAttribute
-	{
-		public ChildFieldsAttribute( params string[] values ) : base( values ) { }
-	}
-
-	public class ChildPropsAttribute : ChildAttribute
-	{
-		public ChildPropsAttribute( params string[] values ) : base( values ) { }
-	}
-
 	public enum Datastructure
 	{
 		Invalid,
@@ -143,7 +89,7 @@ namespace lib
 		public BackingFieldNaming Naming = BackingFieldNaming.Short;
 		public POD POD = POD.Attributes;
 
-		public Types TypesDefault = Types.Fields;
+		public ser.Types TypesDefault = ser.Types.Fields;
 	}
 
 	public class XmlFormatter2 : IFormatter
@@ -328,7 +274,7 @@ namespace lib
 						{
 							object obj = DeserializeObject( elem, mi, type, existing );
 
-							if( obj is I_Serialize iser )
+							if( obj is ser.I_Serialize iser )
 							{
 								if( _cfg.VerboseLogging ) log.info( $"" );
 								obj = iser.OnDeserialize( null );
@@ -561,8 +507,8 @@ namespace lib
 
 					string name = childFi.Name;
 
-					var dontAtt = childFi.GetCustomAttributes<lib.Dont>();
-					var doAtt = childFi.GetCustomAttributes<lib.Do>();
+					var dontAtt = childFi.GetCustomAttributes<ser.Dont>();
+					var doAtt = childFi.GetCustomAttributes<ser.Do>();
 
 					string propName = "";
 
@@ -574,9 +520,9 @@ namespace lib
 
 						var propInfo = narrowType.GetProperty( propName );
 
-						dontAtt = propInfo.GetCustomAttributes<lib.Dont>();
+						dontAtt = propInfo.GetCustomAttributes<ser.Dont>();
 
-						doAtt = propInfo.GetCustomAttributes<lib.Do>();
+						doAtt = propInfo.GetCustomAttributes<ser.Do>();
 					}
 
 					if( dontAtt.Any() )
@@ -639,13 +585,13 @@ namespace lib
 				foreach( var childPi in props )
 				{
 					string name = childPi.Name;
-					var dontAtt = childPi.GetCustomAttributes<lib.Dont>();
+					var dontAtt = childPi.GetCustomAttributes<ser.Dont>();
 					if( dontAtt.Any() )
 					{
 						continue;
 					}
 
-					var doAtt = childPi.GetCustomAttributes<lib.Do>();
+					var doAtt = childPi.GetCustomAttributes<ser.Do>();
 
 
 					name = refl.TypeToIdentifier( name );
@@ -713,7 +659,7 @@ namespace lib
 		{
 			if( doImpls )
 			{
-				if( mi.GetCustomAttribute<ChildAttribute>( true ) == null )
+				if( mi.GetCustomAttribute<ser.ChildAttribute>( true ) == null )
 					return true;
 			}
 
@@ -1353,8 +1299,8 @@ namespace lib
 				foreach( var childFi in fields )
 				{
 					string name = childFi.Name;
-					var dontAtt = childFi.GetCustomAttributes<lib.Dont>();
-					var doAtt = childFi.GetCustomAttributes<lib.Do>();
+					var dontAtt = childFi.GetCustomAttributes<ser.Dont>();
+					var doAtt = childFi.GetCustomAttributes<ser.Do>();
 
 					string propName = "";
 					if( name.StartsWith( "<" ) && name.EndsWith( "BackingField" ) )
@@ -1365,8 +1311,8 @@ namespace lib
 
 						var propInfo = narrowType.GetProperty( propName );
 
-						dontAtt = propInfo.GetCustomAttributes<lib.Dont>();
-						doAtt = propInfo.GetCustomAttributes<lib.Do>();
+						dontAtt = propInfo.GetCustomAttributes<ser.Dont>();
+						doAtt = propInfo.GetCustomAttributes<ser.Do>();
 					}
 
 
@@ -1411,7 +1357,7 @@ namespace lib
 				{
 					string name = childPi.Name;
 
-					var dontAtt = childPi.GetCustomAttributes<lib.Dont>();
+					var dontAtt = childPi.GetCustomAttributes<ser.Dont>();
 					if( dontAtt.Any() )
 					{
 						continue;
@@ -1441,19 +1387,19 @@ namespace lib
 
 		}
 
-		private static void GetFilters( Types TypesDefault, MemberInfo mi, Type type, out bool filterFields, out bool filterProps, out bool doImpls, out bool doFields, out bool doProps, out HashSet<string> whitelistFields, out HashSet<string> whitelistProps )
+		private static void GetFilters( ser.Types TypesDefault, MemberInfo mi, Type type, out bool filterFields, out bool filterProps, out bool doImpls, out bool doFields, out bool doProps, out HashSet<string> whitelistFields, out HashSet<string> whitelistProps )
 		{
-			var custWLFields = mi?.GetCustomAttribute<ChildFieldsAttribute>( true );
-			var custWLProps = mi?.GetCustomAttribute<ChildPropsAttribute>( true );
+			var custWLFields = mi?.GetCustomAttribute<ser.ChildFieldsAttribute>( true );
+			var custWLProps = mi?.GetCustomAttribute<ser.ChildPropsAttribute>( true );
 
 			filterFields = custWLFields != null;
 			filterProps  = custWLProps != null;
 
-			var typesTodo = type.GetCustomAttribute<Ser>( true )?.Types ?? TypesDefault;
+			var typesTodo = type.GetCustomAttribute<ser.Ser>( true )?.Types ?? TypesDefault;
 
-			doImpls  = typesTodo.HasFlag( Types.Implied );
-			doFields = filterFields || typesTodo.HasFlag( Types.Fields );
-			doProps  = filterProps  || typesTodo.HasFlag( Types.Props );
+			doImpls  = typesTodo.HasFlag( ser.Types.Implied );
+			doFields = filterFields || typesTodo.HasFlag( ser.Types.Fields );
+			doProps  = filterProps  || typesTodo.HasFlag( ser.Types.Props );
 			whitelistFields = new( custWLFields?.Values ?? new string[0] );
 			whitelistProps  = new( custWLProps?.Values ?? new string[0] );
 		}

ser/XmlSer_Core.cs

@@ -0,0 +1,159 @@
+
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.Serialization;
+using System.Xml;
+
+namespace ser;
+
+
+// --- Primitive Handler ---
+public partial class PrimitiveHandler : ser.ITypeHandler
+{
+	public bool CanHandle( TypeInfo ti, XmlElement? elem )
+	{
+		var typeCode = Type.GetTypeCode( ti.Type );
+		var typeNotObject = Type.GetTypeCode( ti.Type ) != TypeCode.Object;
+		var isString = ti.Type == typeof( string );
+		return typeNotObject | isString;
+	}
+}
+
+// --- Proxy Handler ---
+public partial class ProxyHandler : ITypeHandler
+{
+	public bool CanHandle( TypeInfo ti, XmlElement? elem ) => ti.IsProxy || ( elem?.HasAttribute( "proxy" ) ?? false );
+}
+
+// --- ISerializable Handler ---
+public partial class ISerializableHandler : ITypeHandler
+{
+	public bool CanHandle( TypeInfo ti, XmlElement? elem ) => ti.IsISerializable;
+}
+
+// --- Collection Handler ---
+public partial class CollectionHandler : ITypeHandler
+{
+	public bool CanHandle( TypeInfo ti, XmlElement? elem ) =>
+			typeof( IEnumerable ).IsAssignableFrom( ti.Type );
+
+	private Type GetElementType( Type collectionType )
+	{
+		if( collectionType.IsArray )
+			return collectionType.GetElementType()!;
+		if( collectionType.IsGenericType )
+		{
+			var args = collectionType.GetGenericArguments();
+			if( args.Length == 1 )
+				return args[0];
+			if( args.Length == 2 )
+				return typeof( KeyValuePair<,> ).MakeGenericType( args );
+		}
+		return typeof( object ); // Fallback
+	}
+
+	private object ConvertToFinalCollection( IList list, Type expectedType, Type elemType )
+	{
+		if( expectedType.IsArray )
+		{
+			var arr = Array.CreateInstance( elemType, list.Count );
+			list.CopyTo( arr, 0 );
+			return arr;
+		}
+		if( expectedType.IsGenericType )
+		{
+			var genDef = expectedType.GetGenericTypeDefinition();
+			if( genDef == typeof( ImmutableArray<> ) )
+			{
+				var method = typeof( ImmutableArray ).GetMethods()
+						.First( m => m.Name == "ToImmutableArray" && m.GetParameters().Length == 1 && m.GetParameters()[0].ParameterType.IsGenericType && m.GetParameters()[0].ParameterType.GetGenericTypeDefinition() == typeof( IEnumerable<> ) )
+						.MakeGenericMethod( elemType );
+				return method.Invoke( null, new object[] { list } )!;
+			}
+			if( genDef == typeof( ImmutableList<> ) )
+			{
+				var method = typeof( ImmutableList ).GetMethods()
+						.First( m => m.Name == "ToImmutableList" && m.GetParameters().Length == 1 && m.GetParameters()[0].ParameterType.IsGenericType && m.GetParameters()[0].ParameterType.GetGenericTypeDefinition() == typeof( IEnumerable<> ) )
+						.MakeGenericMethod( elemType );
+				return method.Invoke( null, new object[] { list } )!;
+			}
+			// Add more immutable/dictionary handlers here (using MakeImmutableDictionary etc.)
+		}
+		return list; // Default to List<T> if no specific match
+	}
+}
+
+
+// --- Object Handler (Default/Complex) ---
+public partial class ObjectHandler : ITypeHandler
+{
+	public bool CanHandle( TypeInfo ti, XmlElement? elem ) => true; // Fallback
+
+	private (XmlNode? source, bool isAttribute) FindValueSource( XmlElement parent, string name )
+	{
+		if( parent.HasAttribute( name ) )
+		{
+			return (parent.Attributes[name], true);
+		}
+		foreach( XmlNode node in parent.ChildNodes )
+		{
+			if( node.NodeType == XmlNodeType.Element && node.Name == name )
+			{
+				return (node, false);
+			}
+		}
+		return (null, false);
+	}
+
+	private bool ShouldSetValue( MemberMeta member, bool isHydrating )
+	{
+		// [Dont] members are filtered out during metadata generation.
+		// If a member is present in the metadata and a value is found in the XML,
+		// we should always set it. This handles both new creation and hydration/merge.
+		return true;
+
+	}
+
+
+	private (object? obj, long id) GetOrCreateInstance( XmlSer xml, XmlElement elem, Type type, object? existing )
+	{
+		long id = -1;
+		bool first = true;
+
+		// Check existing
+		if( existing != null && type.IsAssignableFrom( existing.GetType() ) )
+		{
+			id = xml._idGen.GetId( existing, out first );
+			return (existing, id);
+		}
+
+		// Create new
+		object? newObj = null;
+		try
+		{
+			if( type.GetConstructor( Type.EmptyTypes ) != null )
+			{
+				newObj = Activator.CreateInstance( type );
+			}
+			else
+			{
+				newObj = FormatterServices.GetUninitializedObject( type );
+			}
+		}
+		catch( Exception ex )
+		{
+			log.error( $"Failed to create instance of {type.Name}: {ex.Message}" );
+			return (null, -1);
+		}
+
+		id = xml._idGen.GetId( newObj, out first );
+		return (newObj, id);
+	}
+}
+

ser/XmlSer_Read.cs

@@ -0,0 +1,188 @@
+
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.Serialization;
+using System.Xml;
+
+namespace ser;
+
+
+// --- Primitive Handler ---
+public partial class PrimitiveHandler : ser.ITypeHandler
+{
+	public object? ReadXml( XmlSer xml, XmlElement elem, Type expectedType, object? existing )
+	{
+		string val = elem.HasAttribute( "v" ) ? elem.GetAttribute( "v" ) : elem.InnerText;
+		if( val == "null" )
+			return null;
+
+		// So this is an interesting one. Why not use the expected type? Well, we know we have
+		// data in the XML, it just wont convert to what we want.
+		return xml._resolver.ConvertSimple( val, expectedType );
+	}
+}
+
+// --- Proxy Handler ---
+public partial class ProxyHandler : ITypeHandler
+{
+	public object? ReadXml( XmlSer xml, XmlElement elem, Type expectedType, object? existing )
+	{
+		var ti = xml._meta.Get( expectedType ); // Re-get to ensure we have proxy info
+		if( !elem.HasAttribute( "proxy" ) || !ti.ProxyDef.HasValue )
+		{
+			log.warn( $"Proxy read failed for {expectedType.Name}. Fallback needed." );
+			return null; // Should fall back or throw
+		}
+		var proxyVal = elem.GetAttribute( "proxy" );
+		return ti.ProxyDef.Value.fnDes( expectedType.FullName, proxyVal );
+	}
+}
+
+// --- ISerializable Handler ---
+public partial class ISerializableHandler : ITypeHandler
+{
+	public object? ReadXml( XmlSer xml, XmlElement elem, Type expectedType, object? existing )
+	{
+		// Create/Get instance (needs FormatterServices for ISerializable)
+		object obj = existing ?? FormatterServices.GetUninitializedObject( expectedType );
+		long id = xml.TrackIfGraph( obj, elem ); // Track it
+
+		var serInfo = new SerializationInfo( expectedType, new FormatterConverter() );
+
+		foreach( XmlNode objNode in elem.ChildNodes )
+		{
+			if( objNode is XmlElement childElem )
+			{
+				string childName = childElem.Name;
+				Type? childType = xml._resolver.FindType( childElem.GetAttribute( "_.t" ) );
+				if( childType != null )
+				{
+					var desValue = xml.ReadNode( childElem, childType, null );
+					serInfo.AddValue( childName, desValue, childType );
+				}
+			}
+		}
+
+		var context = new StreamingContext( StreamingContextStates.All ); // Or use xml.Context
+		var cons = expectedType.GetConstructor(
+				BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic,
+				null, new[] { typeof( SerializationInfo ), typeof( StreamingContext ) }, null );
+
+		if( cons != null )
+		{
+			cons.Invoke( obj, new object[] { serInfo, context } );
+		}
+		else
+		{
+			log.error( $"ISerializable type {expectedType.Name} lacks the required constructor." );
+		}
+
+		if( obj is IDeserializationCallback cb )
+			cb.OnDeserialization( obj );
+
+		return obj;
+	}
+}
+
+// --- Collection Handler ---
+public partial class CollectionHandler : ITypeHandler
+{
+
+	public object? ReadXml( XmlSer xml, XmlElement elem, Type expectedType, object? existing )
+	{
+		// Determine element type
+		Type elemType = GetElementType( expectedType );
+
+		// Create a temporary list
+		var listType = typeof( List<> ).MakeGenericType( elemType );
+		var list = (IList)Activator.CreateInstance( listType )!;
+
+		xml.TrackIfGraph( list, elem ); // Track list if graph
+
+		// Populate the list
+		foreach( XmlNode node in elem.ChildNodes )
+		{
+			if( node is XmlElement childElem )
+			{
+				list.Add( xml.ReadNode( childElem, elemType, null ) );
+			}
+		}
+
+		// Convert to the final expected type (Array, Immutable*, List)
+		return ConvertToFinalCollection( list, expectedType, elemType );
+	}
+}
+
+
+// --- Object Handler (Default/Complex) ---
+public partial class ObjectHandler : ITypeHandler
+{
+	public object? ReadXml( XmlSer xml, XmlElement elem, Type expectedType, object? existing )
+	{
+		var actualType = xml._resolver.Resolve( elem, expectedType );
+		var ti = xml._meta.Get( actualType );
+
+		// 1. Get/Create Instance
+		var (obj, _) = GetOrCreateInstance( xml, elem, actualType, existing );
+		if( obj == null )
+			return null;
+
+		// Handle graph refs (if already processed)
+		if( xml._cfg.Structure == Datastructure.Graph && elem.HasAttribute( "ref" ) )
+		{
+			long id = long.Parse( elem.GetAttribute( "ref" ) );
+			if( xml._processed.TryGetValue( id, out var processedObj ) )
+				return processedObj;
+		}
+
+		// Track if it's new
+		xml.TrackIfGraph( obj, elem );
+
+		// 2. Hydrate
+		foreach( var memberMeta in ti.Members )
+		{
+
+
+
+			{
+			var (valueSource, isAttribute) = FindValueSource( elem, memberMeta.XmlName );
+
+			if( valueSource != null )
+			{
+				object? memberValue;
+				object? currentMemberValue = memberMeta.GetValue( obj );
+
+				if( isAttribute )
+				{
+					memberValue = xml._resolver.ConvertSimple( valueSource.Value!, memberMeta.Type );
+				}
+				else // Child Element
+				{
+					memberValue = xml.ReadNode( (XmlElement)valueSource, memberMeta.Type, currentMemberValue );
+				}
+
+				// Set value, respecting ser.Do/ser.Dont and pre-hydration
+				if( ShouldSetValue( memberMeta, existing != null ) )
+				{
+					memberMeta.SetValue( obj, memberValue );
+				}
+			}
+			}
+		}
+
+		// 3. Post-processing
+		if( obj is ser.I_Serialize iSer )
+			obj = iSer.OnDeserialize( null );
+		if( ti.IsImm && obj is imm.Obj immObj )
+			return immObj.Record( $"From XML {elem.Name}" );
+
+		return obj;
+	}
+}
+

ser/XmlSer_Tests.cs

@@ -0,0 +1,133 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+//using Org.BouncyCastle.Crypto.IO;
+
+namespace ser;
+
+
+public record class SimpleImmutable( string Name, int Age ) : imm.Timed<SimpleImmutable>;
+
+static public class Test
+{
+
+	public class ExternalClass
+	{
+		public string ActualProperty { get; set; } = "test_ActualProperty_set_inline";
+		//public string ActualProperty_NotSerialized { get; set; } = "ActualProperty_NotSerialized";
+	}
+
+	[ser.Ser( Types = ser.Types.Implied )]
+	public partial class LeaveWithExternalClasss
+	{
+
+		//[ser.Do]
+		//public bool _cccwp_doBool = true;
+
+		[ser.ChildPropsAttribute( "ActualProperty" )]
+		public ExternalClass _leaf_external = new();
+
+		//public string _cccwp_doNotSerialize = "test_do_not_serialize";
+
+	}
+
+	[ser.Ser]
+	public class TrunkClass
+	{
+		public LeaveWithExternalClasss _trunk_leaf = new();
+		//public int _chf_test = 10;
+		//private string _chf_priv_string = "test_priv_string";
+	};
+
+	public static void Serialization()
+	{
+		ser.XmlCfg cfg = new()
+		{
+			Verbose = true,
+		};
+
+		ser.TypeMetaCache metaCache = new( cfg );
+		//metaCache.AddType( typeof( ClassContainsClassWithProp ), "ActualProperty" );
+
+
+
+
+		TrunkClass trunk = new()
+		{
+			_trunk_leaf = new()
+			{
+				_leaf_external = new()
+				{
+					ActualProperty = "ActualProperty_set_in_cons"
+				}
+			}
+		};
+
+		Debug.Assert( trunk._trunk_leaf._leaf_external.ActualProperty == "ActualProperty_set_in_cons" );
+
+
+		var memStream = new MemoryStream();
+
+		{
+			var xml = new ser.XmlSer( cfg, metaCache );
+			xml.Serialize( memStream, trunk );
+		}
+
+		memStream.Position = 0;
+
+		var strXml = System.Text.Encoding.UTF8.GetString( memStream.ToArray() );
+
+		var badXml = "<root>\n  <prop doBool=\"True\" />\n</root>";
+		///*
+		var badXml_02 = @"""<root>
+  <prop doBool=""True"">
+    <propHolder>
+      <ActualProperty ActualProperty=""ActualProperty_set_in_cons"" />
+      <ActualProperty_NotSerialized ActualProperty_NotSerialized=""ActualProperty_NotSerialized"" />
+    </propHolder>
+    <doNotSerialize doNotSerialize=""test_do_not_serialize"" />
+  </prop>
+</root>""";
+//*/
+		Debug.Assert( strXml != badXml );
+
+		memStream.Position = 0;
+
+		var classHasFields2 = new TrunkClass();
+		//classHasFields2._chf_prop._cccwp_propHolder.ActualProperty_NotSerialized = "ActualProperty_NotSerialized_set_in_test_01";
+
+		Debug.Assert( trunk._trunk_leaf._leaf_external.ActualProperty == "test_ActualProperty_set_inline" );
+		//Debug.Assert( classHasFields2._chf_prop._cccwp_propHolder.ActualProperty_NotSerialized == "ActualProperty_NotSerialized" );
+
+
+		{
+			var xml = new ser.XmlSer(cfg, metaCache);
+			classHasFields2 = xml.Deserialize<TrunkClass>( memStream );
+		}
+
+
+		Debug.Assert( trunk._trunk_leaf._leaf_external.ActualProperty == "test_ActualProperty_set_inline" );
+		//Debug.Assert( classHasFields2._chf_prop._cccwp_propHolder.ActualProperty_NotSerialized == "ActualProperty_NotSerialized_set_in_test_01" );
+
+		memStream.Position = 0;
+
+		var classHasFields3 = new TrunkClass();
+
+		{
+			var xml = new ser.XmlSer(cfg, metaCache);
+			xml.DeserializeInto( memStream, classHasFields3 );
+		}
+
+		Debug.Assert( trunk._trunk_leaf._leaf_external.ActualProperty == "test_ActualProperty_set_inline" );
+		//Debug.Assert( classHasFields3._chf_prop._cccwp_propHolder.ActualProperty_NotSerialized == "ActualProperty_NotSerialized_set_in_test_01" );
+
+
+	}
+
+
+
+}
+

ser/XmlSer_Write.cs

@@ -0,0 +1,193 @@
+
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.Serialization;
+using System.Xml;
+
+namespace ser;
+
+
+// --- Primitive Handler ---
+public partial class PrimitiveHandler : ser.ITypeHandler
+{
+	public void WriteXml( XmlSer xml, XmlWriter writer, object? obj, string name, Type memberType, bool forceType )
+	{
+		if( obj == null )
+		{
+			writer.WriteStartElement( name );
+			writer.WriteAttributeString( "v", "null" );
+			writer.WriteEndElement();
+			return;
+		}
+
+		bool writeElements = xml._cfg.POD == POD.Elements || forceType || !( writer is XmlTextWriter );
+		if( !writeElements && writer is XmlTextWriter tw )
+			writeElements = tw.WriteState != WriteState.Element;
+
+		if( writeElements )
+			writer.WriteStartElement( name );
+
+		if( forceType || xml._cfg.POD == POD.Elements )
+		{
+			if( forceType )
+				writer.WriteAttributeString( "_.t", obj.GetType().FullName );
+
+			writer.WriteAttributeString( "v", obj.ToString() );
+		}
+		else
+		{
+			writer.WriteAttributeString( name, obj.ToString() );
+		}
+
+		if( writeElements )
+			writer.WriteEndElement();
+	}
+}
+
+// --- Proxy Handler ---
+public partial class ProxyHandler : ITypeHandler
+{
+	public void WriteXml( XmlSer xml, XmlWriter writer, object? obj, string name, Type memberType, bool forceType )
+	{
+		if( obj == null )
+		{ xml.GetHandler( typeof( object ) ).WriteXml( xml, writer, null, name, memberType, forceType ); return; }
+
+		var ti = xml._meta.Get( obj.GetType() );
+		if( !ti.ProxyDef.HasValue )
+		{ log.error( "Proxy write called without proxy def!" ); return; }
+
+		writer.WriteStartElement( name );
+		var proxyStr = ti.ProxyDef.Value.fnSer( obj );
+
+		// TODO: Allow arbitrary writing here
+		writer.WriteAttributeString( "proxy", proxyStr );
+		writer.WriteEndElement();
+	}
+}
+
+// --- ISerializable Handler ---
+public partial class ISerializableHandler : ITypeHandler
+{
+	public void WriteXml( XmlSer xml, XmlWriter writer, object? obj, string name, Type memberType, bool forceType )
+	{
+		if( obj == null )
+		{ /* Write null */ return; }
+		if( !( obj is ISerializable serObj ) )
+		{ /* Error */ return; }
+
+		writer.WriteStartElement( name );
+		xml.WriteTypeAttr( writer, memberType, obj.GetType() );
+
+		if( xml.HandleGraphWrite( writer, obj, out bool first ) )
+		{
+			if( first )
+			{
+				var serInfo = new SerializationInfo( obj.GetType(), new FormatterConverter() );
+				var context = new StreamingContext( StreamingContextStates.All );
+				serObj.GetObjectData( serInfo, context );
+
+				foreach( var member in serInfo )
+				{
+					xml.WriteNode( writer, member.Value, refl.TypeToIdentifier( member.Name ), member.ObjectType, true ); // Force type for ISer
+				}
+			}
+		}
+		writer.WriteEndElement();
+	}
+}
+
+// --- Collection Handler ---
+public partial class CollectionHandler : ITypeHandler
+{
+	public void WriteXml( XmlSer xml, XmlWriter writer, object? obj, string name, Type memberType, bool forceType )
+	{
+		if( obj == null )
+		{ /* Write null */ return; }
+		if( !( obj is IEnumerable collection ) )
+		{ /* Error */ return; }
+
+		writer.WriteStartElement( name );
+		xml.WriteTypeAttr( writer, memberType, obj.GetType() );
+
+		if( xml.HandleGraphWrite( writer, obj, out bool first ) )
+		{
+			if( first )
+			{
+				Type elemType = GetElementType( obj.GetType() );
+				int i = 0;
+				foreach( var item in collection )
+				{
+					xml.WriteNode( writer, item, $"i{i++}", elemType, false );
+				}
+			}
+		}
+		writer.WriteEndElement();
+	}
+}
+
+
+// --- Object Handler (Default/Complex) ---
+public partial class ObjectHandler : ITypeHandler
+{
+	public void WriteXml( XmlSer xml, XmlWriter writer, object? obj, string name, Type memberType, bool forceType )
+	{
+		if( obj == null )
+		{ /* Write null */ return; }
+
+		writer.WriteStartElement( name );
+		xml.WriteTypeAttr( writer, memberType, obj.GetType() );
+		var ti = xml._meta.Get( obj.GetType() );
+
+		if( xml.HandleGraphWrite( writer, obj, out bool first ) )
+		{
+			if( first )
+			{
+				foreach( var memberMeta in ti.Members )
+				{
+					var value = memberMeta.GetValue( obj );
+					if( value != null )
+					{
+						// If POD-Attribute, write attribute
+						if( memberMeta.IsPodAttribute )
+						{
+							try
+							{
+								writer.WriteAttributeString( memberMeta.XmlName, value.ToString() );
+							}
+							catch( Exception ex )
+							{
+								log.error( $"Writing Att {memberMeta.XmlName} = [{value}]" );
+							}
+						}
+						else
+						{
+							try
+							{
+								xml.WriteNode( writer, value, memberMeta.XmlName, memberMeta.Type, false );
+							}
+							catch( Exception ex )
+							{
+								log.error( $"Writing Node {memberMeta.XmlName} = [{value}]" );
+							}
+						}
+					}
+
+
+				}
+
+
+
+
+			}
+		}
+
+		writer.WriteEndElement();
+	}
+}
+

tests/Tests.cs

@@ -0,0 +1,125 @@
+
+
+
+
+
+
+using System.Diagnostics;
+using System.IO;
+
+namespace test;
+
+
+public record class SimpleImmutable( string Name, int Age ) : imm.Timed<SimpleImmutable>;
+
+static public class XmlFormatter2
+{
+
+	public class ClassWithProperties
+	{
+		public string ActualProperty { get; set; } = "test_ActualProperty_set_inline";
+		public string ActualProperty_NotSerialized { get; set; } = "ActualProperty_NotSerialized";
+	}
+
+	[ser.Ser( Types = ser.Types.Implied )]
+	public partial class ClassContainsClassWithProp
+	{
+
+		[ser.Do]
+		public bool doBool = true;
+
+		[ser.ChildPropsAttribute( "ActualProperty" )]
+		public ClassWithProperties propHolder = new();
+
+		public string doNotSerialize = "test_do_not_serialize";
+
+	}
+
+	[ser.Ser]
+	public class ClassHasFields
+	{
+		public ClassContainsClassWithProp prop = new();
+	};
+
+	public static void Serialization()
+	{
+
+		lib.XmlFormatter2Cfg cfg = new()
+		{
+
+		};
+
+
+
+
+		ClassHasFields classHasFields = new()
+		{
+			prop = new()
+			{
+				propHolder = new()
+				{
+					ActualProperty = "ActualProperty_set_in_cons"
+				}
+			}
+		};
+
+		Debug.Assert( classHasFields.prop.propHolder.ActualProperty == "ActualProperty_set_in_cons" );
+
+
+		var memStream = new MemoryStream();
+
+		{
+			var xml = new lib.XmlFormatter2	( cfg );
+			xml.Serialize( memStream, classHasFields );
+		}
+
+		memStream.Position = 0;
+
+		var strXml = System.Text.Encoding.UTF8.GetString( memStream.ToArray() );
+
+		var badXml = "<root>\n  <prop doBool=\"True\" />\n</root>";
+		/*
+<root _.t="test.XmlFormatter2+ClassHasFields" _.version.="2">
+  <prop doBool="True">
+    <propHolder ActualProperty="ActualProperty_set_in_cons" ActualProperty_NotSerialized="ActualProperty_NotSerialized" ActualProperty="ActualProperty_set_in_cons" />
+  </prop>
+</root>*/
+		Debug.Assert( strXml != badXml );
+
+		memStream.Position = 0;
+
+		var classHasFields2 = new ClassHasFields();
+		classHasFields2.prop.propHolder.ActualProperty_NotSerialized = "ActualProperty_NotSerialized_set_in_test_01";
+
+		Debug.Assert( classHasFields2.prop.propHolder.ActualProperty == "test_ActualProperty_set_inline" );
+		Debug.Assert( classHasFields2.prop.propHolder.ActualProperty_NotSerialized == "ActualProperty_NotSerialized" );
+
+
+		{
+			var xml = new lib.XmlFormatter2	( cfg );
+			classHasFields2 = xml.Deserialize<ClassHasFields>( memStream );
+		}
+
+
+		Debug.Assert( classHasFields2.prop.propHolder.ActualProperty == "ActualProperty_set_in_cons" );
+		Debug.Assert( classHasFields2.prop.propHolder.ActualProperty_NotSerialized == "ActualProperty_NotSerialized_set_in_test_01" );
+
+		memStream.Position = 0;
+
+		var classHasFields3 = new ClassHasFields();
+
+		{
+			var xml = new lib.XmlFormatter2	( cfg );
+			xml.DeserializeInto( memStream, classHasFields3 );
+		}
+
+		Debug.Assert( classHasFields3.prop.propHolder.ActualProperty == "ActualProperty_set_in_cons" );
+		Debug.Assert( classHasFields3.prop.propHolder.ActualProperty_NotSerialized == "ActualProperty_NotSerialized_set_in_test_01" );
+
+
+	}
+
+
+
+}
+