Fixed issue when bindingContext is bound more than once.

apps/tests/ui/bindable-tests.ts

@@ -10,6 +10,7 @@ import utils = require("utils/utils");
 import pageModule = require("ui/page");
 import stackLayoutModule = require("ui/layouts/stack-layout");
 import bindingBuilder = require("ui/builder/binding-builder");
+import labelModule = require("ui/label");
 
 // <snippet module="ui/core/bindable" title="bindable">
 // For information and examples how to use bindings please refer to special [**Data binding**](../../../../bindings.md) topic. 
@@ -459,4 +460,17 @@ export var test_getBindableOptionsFromStringTwoParamsNamedFormat = function () {
     TKUnit.assert(bindOptions.targetProperty === "targetBindProperty", "Expected: targetBindProperty, Actual: " + bindOptions.targetProperty);
     TKUnit.assert(bindOptions.expression === "bindProperty * 2", "Expected: bindProperty * 2, Actual:" + bindOptions.expression);
     TKUnit.assert(bindOptions.twoWay === true, "Expected: true, Actual: " + bindOptions.twoWay);
+}
+
+export var test_TwoElementsBindingToSameBindingContext = function () {
+    var testFunc = function (page: pageModule.Page) {
+        var upperStackLabel = <labelModule.Label>(page.getViewById("upperStackLabel"));
+        var label1 = <labelModule.Label>(page.getViewById("label1"));
+        var label2 = <labelModule.Label>(page.getViewById("label2"));
+
+        TKUnit.assertEqual(upperStackLabel.text, label1.text);
+        TKUnit.assertEqual(upperStackLabel.text, label2.text);
+    }
+
+    helper.navigateToModuleAndRunTest("./tests/ui/bindingContext_testPage", testFunc);
 }

apps/tests/ui/bindingContext_testPage.ts

@@ -0,0 +1,34 @@
+import observableModule = require("data/observable");
+import pageModule = require("ui/page");
+
+class MainViewModel extends observableModule.Observable {
+    private _item: any;
+
+    constructor() {
+        super();
+
+        this.item = { Title: "Alabala" };
+    }
+
+    get item(): any {
+        return this._item;
+    }
+
+    set item(value: any) {
+        if (this._item !== value) {
+            this._item = value;
+            this.notifyPropertyChanged("item", value);
+        }
+    }
+
+    notifyPropertyChanged(propertyName: string, value: any) {
+        this.notify({ object: this, eventName: observableModule.Observable.propertyChangeEvent, propertyName: propertyName, value: value });
+    }
+}
+
+var viewModel = new MainViewModel();
+
+export function pageLoaded(args: observableModule.EventData) {
+    var page = <pageModule.Page>args.object;
+    page.bindingContext = viewModel;
+}

apps/tests/ui/bindingContext_testPage.xml

@@ -0,0 +1,15 @@
+<Page xmlns="http://www.nativescript.org/tns.xsd"
+      xmlns:g="components/grid-view/grid-view"
+      loaded="pageLoaded">
+	<StackLayout id="upperStack">
+		<Label id="upperStackLabel" text="{{ item.Title }}" />
+		<StackLayout id="firstStack" bindingContext="{{ item }}" orientation="horizontal">
+			<Label id="labelText1" text="1" />
+			<Label id="label1" text="{{ Title }}" />
+		</StackLayout>
+		<StackLayout id="secondStack" bindingContext="{{ item }}" orientation="horizontal">
+			<Label id="labelText2" text="2" />
+			<Label id="label2" text="{{ Title }}" />
+		</StackLayout>
+	</StackLayout>
+</Page>

apps/tests/ui/helper.ts

@@ -143,6 +143,16 @@ export function buildUIAndRunTest(controlToTest, testFunction, pageCss?) {
     }
 }
 
+export function navigateToModuleAndRunTest(moduleName, testFunction) {
+    navigateToModule(moduleName);
+    try {
+        testFunction(frame.topmost().currentPage);
+    }
+    finally {
+        goBack();
+    }
+}
+
 export function buildUIWithWeakRefAndInteract<T extends view.View>(createFunc: () => T, interactWithViewFunc?: (view: T) => void) {
     var newPage: page.Page;
     var testFinished = false;