remove oldDataSource second way bindings

2 files changed, 37 insertions, 8 deletions

diff --git a/src/CompilerServices/CompilerServices.cs b/src/CompilerServices/CompilerServices.cs
index dc95aca8..b7d24184 100644
--- a/src/CompilerServices/CompilerServices.cs
+++ b/src/CompilerServices/CompilerServices.cs
@@ -167,7 +167,7 @@ namespace Crow
 					il.Emit (OpCodes.Callvirt, miParse);
 
 					if (miParse.ReturnType != pi.PropertyType)
-						il.Emit (OpCodes.Unbox_Any, pi.PropertyType);					
+						il.Emit (OpCodes.Unbox_Any, pi.PropertyType);
 				} else {
 					MethodInfo miParse = pi.PropertyType.GetMethod
 						("Parse", BindingFlags.Static | BindingFlags.Public,
@@ -182,7 +182,7 @@ namespace Crow
 						il.Emit (OpCodes.Unbox_Any, pi.PropertyType);
 				}
 			}
-			il.Emit (OpCodes.Callvirt, pi.GetSetMethod ());			
+			il.Emit (OpCodes.Callvirt, pi.GetSetMethod ());
 		}
 
 		public static void ResolveBindings (List<Binding> Bindings)
@@ -470,7 +470,7 @@ namespace Crow
 				il.Emit (OpCodes.Ldarg_0);  //load sender ref onto the stack
 
 				string [] lopParts = lop.Split (new char [] { '.' });
-				if (lopParts.Length > 1) {//should search also for member of es.Source					
+				if (lopParts.Length > 1) {//should search also for member of es.Source
 					for (int j = 0; j < lopParts.Length - 1; j++) {
 						il.Emit (OpCodes.Ldstr, lopParts [j]);
 						il.Emit (OpCodes.Callvirt, miFindByName);
@@ -805,20 +805,34 @@ namespace Crow
 		/// <summary>
 		/// Removes delegate from event handler by name
 		/// </summary>
-		public static void RemoveEventHandler(object instance, string eventName, string delegateName){
+		public static void RemoveEventHandlerByName(object instance, string eventName, string delegateName){
 			Type t = instance.GetType ();
 			FieldInfo fiEvt = CompilerServices.GetEventHandlerField (t, eventName);
 			EventInfo eiEvt = t.GetEvent (eventName);
 			MulticastDelegate multiDel = fiEvt.GetValue (instance) as MulticastDelegate;
 			if (multiDel != null) {
 				foreach (Delegate d in multiDel.GetInvocationList()) {
-					if (d.Method.Name == delegateName) {
+					if (d.Method.Name == delegateName)
 						eiEvt.RemoveEventHandler (instance, d);
-						Debug.WriteLine ("event handler removed: " + delegateName + " in " + t.FullName);
-					}
 				}
 			}
 		}
+		/// <summary>
+		/// Removes delegate from event handler by searching for the object they are bond to
+		/// </summary>
+		public static void RemoveEventHandlerByTarget(object instance, string eventName, object target){
+			Type t = instance.GetType ();
+			FieldInfo fiEvt = CompilerServices.GetEventHandlerField (t, eventName);
+			EventInfo eiEvt = t.GetEvent (eventName);
+			MulticastDelegate multiDel = fiEvt.GetValue (instance) as MulticastDelegate;
+			if (multiDel != null) {
+				foreach (Delegate d in multiDel.GetInvocationList()) {
+					if (d.Target == target)
+						eiEvt.RemoveEventHandler (instance, d);
+				}
+			}
+		}
+
 		public static Delegate compileDynEventHandler(EventInfo sourceEvent, string expression, NodeAddress currentNode = null){
 			Type lopType = null;
 
diff --git a/src/Instantiator.cs b/src/Instantiator.cs
index 5c50db18..cdd229af 100644
--- a/src/Instantiator.cs
+++ b/src/Instantiator.cs
@@ -827,6 +827,21 @@ namespace Crow
 			emitRemoveOldDataSourceHandler(il, "ValueChanged", delName);
 
 			if (!string.IsNullOrEmpty(bindingDef.TargetMember)){
+				if (bindingDef.TwoWay){
+					System.Reflection.Emit.Label cancelRemove = il.DefineLabel ();
+					//remove handler if not null
+					il.Emit (OpCodes.Ldarg_2);//load old parent
+					il.Emit (OpCodes.Ldfld, typeof (DataSourceChangeEventArgs).GetField ("OldDataSource"));
+					il.Emit (OpCodes.Brfalse, cancelRemove);//old parent is null
+
+					//remove handler
+					il.Emit (OpCodes.Ldarg_2);//1st arg load old datasource
+					il.Emit (OpCodes.Ldfld, typeof (DataSourceChangeEventArgs).GetField ("OldDataSource"));
+					il.Emit (OpCodes.Ldstr, "ValueChanged");//2nd arg event name
+					il.Emit (OpCodes.Ldarg_1);//3d arg: instance bound to delegate (the source)
+					il.Emit (OpCodes.Call, typeof(CompilerServices).GetMethod("RemoveEventHandlerByTarget", BindingFlags.Static | BindingFlags.Public));
+					il.MarkLabel(cancelRemove);
+				}
 				il.Emit (OpCodes.Ldarg_2);//load datasource change arg
 				il.Emit (OpCodes.Ldfld, CompilerServices.fiDSCNewDS);
 				il.Emit (OpCodes.Brfalse, cancel);//new ds is null
@@ -949,7 +964,7 @@ namespace Crow
 			il.Emit (OpCodes.Ldfld, typeof (DataSourceChangeEventArgs).GetField ("OldDataSource"));
 			il.Emit (OpCodes.Ldstr, eventName);//2nd arg event name
 			il.Emit (OpCodes.Ldstr, delegateName);//3d arg: delegate name
-			il.Emit (OpCodes.Call, typeof(CompilerServices).GetMethod("RemoveEventHandler", BindingFlags.Static | BindingFlags.Public));
+			il.Emit (OpCodes.Call, typeof(CompilerServices).GetMethod("RemoveEventHandlerByName", BindingFlags.Static | BindingFlags.Public));
 			il.MarkLabel(cancel);
 		}