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@angular/common

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Angular - commonly needed directives and services

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/** * @license * Copyright Google Inc. All Rights Reserved. * * Use of this source code is governed by an MIT-style license that can be * found in the LICENSE file at https://angular.io/license */ import { ChangeDetectorRef, OnDestroy, PipeTransform } from '@angular/core'; import { Observable } from 'rxjs/Observable'; /** * @ngModule CommonModule * @whatItDoes Unwraps a value from an asynchronous primitive. * @howToUse `observable_or_promise_expression | async` * @description * The `async` pipe subscribes to an `Observable` or `Promise` and returns the latest value it has * emitted. When a new value is emitted, the `async` pipe marks the component to be checked for * changes. When the component gets destroyed, the `async` pipe unsubscribes automatically to avoid * potential memory leaks. * * * ## Examples * * This example binds a `Promise` to the view. Clicking the `Resolve` button resolves the * promise. * * {@example common/pipes/ts/async_pipe.ts region='AsyncPipePromise'} * * It's also possible to use `async` with Observables. The example below binds the `time` Observable * to the view. The Observable continuously updates the view with the current time. * * {@example common/pipes/ts/async_pipe.ts region='AsyncPipeObservable'} * * @stable */ export declare class AsyncPipe implements OnDestroy, PipeTransform { private _ref; private _latestValue; private _latestReturnedValue; private _subscription; private _obj; private _strategy; constructor(_ref: ChangeDetectorRef); ngOnDestroy(): void; transform<T>(obj: null): null; transform<T>(obj: undefined): undefined; transform<T>(obj: Observable<T> | null | undefined): T | null; transform<T>(obj: Promise<T> | null | undefined): T | null; private _subscribe(obj); private _selectStrategy(obj); private _dispose(); private _updateLatestValue(async, value); }