feat: allow using KeyValueChanges as a pipe

Author: pkozlowski-opensource

modules/angular2/src/change_detection/pipes/keyvalue_changes.js

@@ -1,8 +1,19 @@
 import {ListWrapper, MapWrapper, StringMapWrapper} from 'angular2/src/facade/collection';
-
 import {stringify, looseIdentical, isJsObject} from 'angular2/src/facade/lang';
 
-export class KeyValueChanges {
+import {NO_CHANGE, Pipe} from './pipe';
+
+export class KeyValueChangesFactory {
+ supports(obj):boolean {
+ return KeyValueChanges.supportsObj(obj);
+ }
+
+ create():Pipe {
+ return new KeyValueChanges();
+ }
+}
+
+export class KeyValueChanges extends Pipe {
  _records:Map;
 
  _mapHead:KVChangeRecord;
@@ -15,6 +26,7 @@ export class KeyValueChanges {
  _removalsTail:KVChangeRecord;
 
  constructor() {
+ super();
  this._records = MapWrapper.create();
  this._mapHead = null;
  this._previousMapHead = null;
@@ -26,12 +38,20 @@ export class KeyValueChanges {
  this._removalsTail = null;
  }
 
- static supports(obj):boolean {
+ static supportsObj(obj):boolean {
  return obj instanceof Map || isJsObject(obj);
  }
 
- supportsObj(obj):boolean {
- return KeyValueChanges.supports(obj);
+ supports(obj):boolean {
+ return KeyValueChanges.supportsObj(obj);
+ }
+
+ transform(map){
+ if (this.check(map)) {
+ return this;
+ } else {
+ return NO_CHANGE;
+ }
  }
 
  get isDirty():boolean {

modules/angular2/test/change_detection/keyvalue_changes_spec.js

@@ -131,10 +131,10 @@ export function main() {
  if (isJsObject({})) {
  describe('JsObject changes', () => {
  it('should support JS Object', () => {
- expect(KeyValueChanges.supports({})).toBeTruthy();
- expect(KeyValueChanges.supports("not supported")).toBeFalsy();
- expect(KeyValueChanges.supports(0)).toBeFalsy();
- expect(KeyValueChanges.supports(null)).toBeFalsy();
+ expect(KeyValueChanges.supportsObj({})).toBeTruthy();
+ expect(KeyValueChanges.supportsObj("not supported")).toBeFalsy();
+ expect(KeyValueChanges.supportsObj(0)).toBeFalsy();
+ expect(KeyValueChanges.supportsObj(null)).toBeFalsy();
  });
 
  it('should do basic object watching', () => {