From adc135e6c87238f8b71875e772388705fd100072 Mon Sep 17 00:00:00 2001
From: Tom Schoener <tom.schoener@hotmail.de>
Date: Sat, 12 Mar 2016 14:22:31 +0100
Subject: [PATCH] refactor(async_pipe): use subscription strategy interface

The strategies for Promise and Observable based subscriptions
have (nearly) the same method signatures. They should implement
a common interface.

Closes #7573
---
 modules/@angular/common/src/pipes/async_pipe.ts | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/modules/@angular/common/src/pipes/async_pipe.ts b/modules/@angular/common/src/pipes/async_pipe.ts
index 6d5febac53..68b87b633f 100644
--- a/modules/@angular/common/src/pipes/async_pipe.ts
+++ b/modules/@angular/common/src/pipes/async_pipe.ts
@@ -5,7 +5,13 @@ import {ObservableWrapper, Observable, EventEmitter} from '../../src/facade/asyn
 
 import {InvalidPipeArgumentException} from './invalid_pipe_argument_exception';
 
-class ObservableStrategy {
+interface SubscriptionStrategy {
+  createSubscription(async: any, updateLatestValue: any, onError?: (v: any) => any): any;
+  dispose(subscription: any): void;
+  onDestroy(subscription: any): void;
+}
+
+class ObservableStrategy implements SubscriptionStrategy {
   createSubscription(async: any, updateLatestValue: any,
                      onError: (v: any) => any = e => { throw e; }): any {
     return ObservableWrapper.subscribe(async, updateLatestValue, onError);
@@ -16,7 +22,7 @@ class ObservableStrategy {
   onDestroy(subscription: any): void { ObservableWrapper.dispose(subscription); }
 }
 
-class PromiseStrategy {
+class PromiseStrategy implements SubscriptionStrategy {
   createSubscription(async: Promise<any>, updateLatestValue: (v: any) => any,
                      onError: (v: any) => any = e => { throw e; }): any {
     return async.then(updateLatestValue, onError);
@@ -61,7 +67,7 @@ export class AsyncPipe implements OnDestroy {
   _subscription: Object = null;
   /** @internal */
   _obj: Observable<any>| Promise<any>| EventEmitter<any> = null;
-  private _strategy: any = null;
+  private _strategy: SubscriptionStrategy = null;
   /** @internal */
   public _ref: ChangeDetectorRef;
   constructor(_ref: ChangeDetectorRef) { this._ref = _ref; }