Fixed Issue #NativeScript#1235: ObservableArray does not raise its change event when its `length' property is set.

hamorphis · hamorphis · commit 7546b7fad400 · 2015-12-11T14:17:29.000+02:00
diff --git a/apps/tests/observable-array-tests.ts b/apps/tests/observable-array-tests.ts
@@ -606,6 +606,46 @@ export var test_ObservableArray_lastIndexOfShouldReturnCorrectIndexStartingFrom
     TKUnit.assert(result === 1, "ObservableArray lastIndexOf() should return correct index!");
 };
 
+export var test_ObservableArray_settingLengthToZeroPerformsSplice = function () {
+    var array = new observableArrayModule.ObservableArray([1, 2, 3]);
+
+    var changeRaised = false;
+    array.on("change", (args: observableArrayModule.ChangedData<number>) => {
+        changeRaised = true;
+        TKUnit.assertEqual(args.object, array);
+        TKUnit.assertEqual(args.eventName, "change");
+        TKUnit.assertEqual(args.action, observableArrayModule.ChangeType.Splice);
+        TKUnit.assertEqual(args.index, 0);
+        TKUnit.assertEqual(args.addedCount, 0);
+        TKUnit.arrayAssert(args.removed, [1, 2, 3]);
+    });
+
+    array.length = 0;
+
+    TKUnit.assertEqual(array.length, 0);
+    TKUnit.assertTrue(changeRaised);
+};
+
+export var test_ObservableArray_settingLengthToSomethingPerformsSplice = function () {
+    var array = new observableArrayModule.ObservableArray([1, 2, 3]);
+
+    var changeRaised = false;
+    array.on("change", (args: observableArrayModule.ChangedData<number>) => {
+        changeRaised = true;
+        TKUnit.assertEqual(args.object, array);
+        TKUnit.assertEqual(args.eventName, "change");
+        TKUnit.assertEqual(args.action, observableArrayModule.ChangeType.Splice);
+        TKUnit.assertEqual(args.index, 1);
+        TKUnit.assertEqual(args.addedCount, 0);
+        TKUnit.arrayAssert(args.removed, [2, 3]);
+    });
+
+    array.length = 1;
+
+    TKUnit.assertEqual(array.length, 1);
+    TKUnit.assertTrue(changeRaised);
+};
+
 var array = new observableArrayModule.ObservableArray();
 
 // We do not have indexer!
diff --git a/data/observable-array/observable-array.ts b/data/observable-array/observable-array.ts
@@ -70,8 +70,7 @@ export class ObservableArray<T> extends observable.Observable implements observa
     }
     set length(value: number) {
         if (types.isNumber(value) && this._array && this._array.length !== value) {
-            this._array = this._array.slice(0, value);
-            this._notifyLengthChange();
+            this.splice(value, this._array.length - value);
         }
     }
 

Original file line number	Diff line number	Diff line change
`@@ -70,8 +70,7 @@ export class ObservableArray<T> extends observable.Observable implements observa`
`70`	`70`	`}`
`71`	`71`	`set length(value: number) {`
`72`	`72`	`if (types.isNumber(value) && this._array && this._array.length !== value) {`
`73`		`- this._array = this._array.slice(0, value);`
`74`		`- this._notifyLengthChange();`
	`73`	`+ this.splice(value, this._array.length - value);`
`75`	`74`	`}`
`76`	`75`	`}`
`77`	`76`