From ab8087e330539c0a6be1b9f7ca49a761db4f1796 Mon Sep 17 00:00:00 2001
From: Steve Sanderson <steve@codeville.net>
Date: Thu, 2 Feb 2012 12:50:29 +0000
Subject: [PATCH] Replace automatic inheritance of all bindingContext
 properties with new $parentContext variable Benefit #1: Can reach custom
 properties on *all* ancestor contexts, and are not limited to those that
 haven't been overwritten (e.g., if we had $index, would now be able to reach
 all ancestor $index values, not just the closest one) Benefit #2: Allows
 discrimination between properties at the current level and properties at the
 parent level, which is good because not all custom properties may make sense
 to inherit.

---
 spec/bindingAttributeBehaviors.js     | 2 +-
 src/binding/bindingAttributeSyntax.js | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/spec/bindingAttributeBehaviors.js b/spec/bindingAttributeBehaviors.js
index 1605770da..b99035dbf 100644
--- a/spec/bindingAttributeBehaviors.js
+++ b/spec/bindingAttributeBehaviors.js
@@ -322,7 +322,7 @@ describe('Binding attribute syntax', {
         ko.applyBindings(null, testNode);
         value_of(ko.contextFor(testNode.childNodes[1].childNodes[0])).should_be(innerContext);
         value_of(ko.contextFor(testNode.childNodes[1].childNodes[1]).$parent).should_be(innerContext.$data);
-        value_of(ko.contextFor(testNode.childNodes[1].childNodes[1]).custom).should_be(true);
+        value_of(ko.contextFor(testNode.childNodes[1].childNodes[1]).$parentContext.custom).should_be(true);
     },
     
     'Should not reinvoke init for notifications triggered during first evaluation': function () {
diff --git a/src/binding/bindingAttributeSyntax.js b/src/binding/bindingAttributeSyntax.js
index e3454817e..eac7270ef 100755
--- a/src/binding/bindingAttributeSyntax.js
+++ b/src/binding/bindingAttributeSyntax.js
@@ -2,17 +2,17 @@
     ko.bindingHandlers = {};
 
     ko.bindingContext = function(dataItem, parentBindingContext) {
+        this['$data'] = dataItem;
         if (parentBindingContext) {
-            // copy all properties from parent binding context
-            ko.utils.extend(this, parentBindingContext);
+            this['$parentContext'] = parentBindingContext;
             this['$parent'] = parentBindingContext['$data'];
-            this['$parents'] = (this['$parents'] || []).slice(0);
+            this['$parents'] = (parentBindingContext['$parents'] || []).slice(0);
             this['$parents'].unshift(this['$parent']);
+            this['$root'] = parentBindingContext['$root'];
         } else {
             this['$parents'] = [];
             this['$root'] = dataItem;        	
         }
-        this['$data'] = dataItem;
     }
     ko.bindingContext.prototype['createChildContext'] = function (dataItem) {
         return new ko.bindingContext(dataItem, this);