From 03fe6ecfd3db074bc3d6ebbf566fd90b1464cefb Mon Sep 17 00:00:00 2001
From: Paul Betts <paul@paulbetts.org>
Date: Mon, 21 Feb 2011 10:40:37 -0800
Subject: [PATCH] Add warning to people who didn't implement
 INotifyPropertyChanging

---
 ReactiveUI/MakeObjectReactiveHelper.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ReactiveUI/MakeObjectReactiveHelper.cs b/ReactiveUI/MakeObjectReactiveHelper.cs
index 2301877f28..e6b2d316db 100644
--- a/ReactiveUI/MakeObjectReactiveHelper.cs
+++ b/ReactiveUI/MakeObjectReactiveHelper.cs
@@ -19,6 +19,9 @@ public MakeObjectReactiveHelper(INotifyPropertyChanged hostObject)
             if (hostChanging != null) {
                 hostChanging.PropertyChanging += (o, e) => _Changing.OnNext(
                     new ObservedChange<object, object>() { Sender = o, PropertyName = e.PropertyName });
+            } else {
+                this.Log().ErrorFormat("'{0}' does not implement INotifyPropertyChanging - RxUI may return duplicate change notifications",
+                    hostObject.GetType().FullName);
             }
 
             hostObject.PropertyChanged += (o, e) => _Changed.OnNext(