Merge pull request #434 from NativeScript/nnikolov/ListViewBindingContextIssue

BindingContext set two times on adding item to ListView. Fixed issue #410.

apps/tests/ui/list-view/list-view-tests.ts

@@ -5,6 +5,7 @@ import viewModule = require("ui/core/view");
 import observable = require("data/observable");
 import types = require("utils/types");
 import platform = require("platform");
+import utils = require("utils/utils");
 
 // <snippet module="ui/list-view" title="list-view">
 // # ListView
@@ -580,6 +581,38 @@ export function test_bindingToParentObjectWithSpacesInIndexer() {
     helper.buildUIAndRunTest(listView, testAction);
 }
 
+export function test_ConverterIsCalledJustOnce_onAddingItemsToListView() {
+    var listView = new listViewModule.ListView();
+    var converterCalledCounter = 0;
+
+    var testConverter = function (value) {
+        converterCalledCounter++;
+        return value;
+    }
+
+    app.resources["testConverter"] = testConverter;
+
+    function testAction(views: Array<viewModule.View>) {
+        var listViewModel = new observable.Observable();
+        listViewModel.set("items", [1, 2, 3]);
+        listView.bindingContext = listViewModel;
+
+        listView.bind({ sourceProperty: "items", targetProperty: "items" });
+        listView.itemTemplate = "<Label id=\"testLabel\" text=\"{{ $value, $value | testConverter }}\" />";
+
+        TKUnit.wait(ASYNC);
+
+        if (utils.ios && utils.ios.MajorVersion < 8) {
+            TKUnit.assertEqual(converterCalledCounter, listViewModel.get("items").length * 2, "Converter should be called once for every item.");
+        }
+        else {
+            TKUnit.assertEqual(converterCalledCounter, listViewModel.get("items").length, "Converter should be called once for every item.");
+        }
+    }
+
+    helper.buildUIAndRunTest(listView, testAction);
+}
+
 export function test_no_memory_leak_when_items_is_regular_array() {
     var createFunc = function (): listViewModule.ListView {
         var listView = new listViewModule.ListView();

ui/core/view-common.ts

@@ -829,9 +829,7 @@ export class View extends proxy.ProxyObject implements definition.View {
      * Method is intended to be overridden by inheritors and used as "protected"
      */
     public _addViewCore(view: View) {
-        view._setValue(bindable.Bindable.bindingContextProperty, this.bindingContext, dependencyObservable.ValueSource.Inherited);
+        this._propagateInheritableProperties(view);
-
-        view._inheritProperties(this);
 
         view.style._inheritStyleProperties();
 
@@ -845,7 +843,11 @@ export class View extends proxy.ProxyObject implements definition.View {
         }
     }
 
-    private _inheritProperties(parentView: View) {
+    public _propagateInheritableProperties(view: View) {
+        view._inheritProperties(this);
+    }
+
+    public _inheritProperties(parentView: View) {
         var that = this;
         var inheritablePropertySetCallback = function (property: dependencyObservable.Property) {
             if (property instanceof styling.Property) {

ui/core/view.d.ts

@@ -409,6 +409,8 @@ declare module "ui/core/view" {
         isLoaded: boolean;
 
         _addView(view: View);
+        _propagateInheritableProperties(view: View)
+        _inheritProperties(parentView: View)
         _removeView(view: View);
         _context: android.content.Context;
 

ui/list-view/list-view-common.ts

@@ -114,6 +114,7 @@ export class ListView extends view.View implements definition.ListView {
     public _prepareItem(item: view.View, index: number) {
         if (item) {
             item.bindingContext = this._getDataItem(index);
+            item._inheritProperties(this);
         }
     }
 
@@ -145,4 +146,8 @@ export class ListView extends view.View implements definition.ListView {
     private _onItemsChanged(args: observable.EventData) {
         this.refresh();
     }
+
+    public _propagateInheritableProperties(view: view.View) {
+        // do not get binding context from parent when adding items, since the binding context of the items will be different.
+    }
 }