| import { Operator } from '../Operator'; |
| import { Subscriber } from '../Subscriber'; |
| import { async } from '../scheduler/async'; |
| import { Observable } from '../Observable'; |
| import { isDate } from '../util/isDate'; |
| import { OuterSubscriber } from '../OuterSubscriber'; |
| import { subscribeToResult } from '../util/subscribeToResult'; |
| import { ObservableInput, OperatorFunction, MonoTypeOperatorFunction, SchedulerAction, SchedulerLike, TeardownLogic } from '../types'; |
| |
| /* tslint:disable:max-line-length */ |
| export function timeoutWith<T, R>(due: number | Date, withObservable: ObservableInput<R>, scheduler?: SchedulerLike): OperatorFunction<T, T | R>; |
| /* tslint:enable:max-line-length */ |
| |
| /** |
| * |
| * Errors if Observable does not emit a value in given time span, in case of which |
| * subscribes to the second Observable. |
| * |
| * <span class="informal">It's a version of `timeout` operator that let's you specify fallback Observable.</span> |
| * |
| * ![](timeoutWith.png) |
| * |
| * `timeoutWith` is a variation of `timeout` operator. It behaves exactly the same, |
| * still accepting as a first argument either a number or a Date, which control - respectively - |
| * when values of source Observable should be emitted or when it should complete. |
| * |
| * The only difference is that it accepts a second, required parameter. This parameter |
| * should be an Observable which will be subscribed when source Observable fails any timeout check. |
| * So whenever regular `timeout` would emit an error, `timeoutWith` will instead start re-emitting |
| * values from second Observable. Note that this fallback Observable is not checked for timeouts |
| * itself, so it can emit values and complete at arbitrary points in time. From the moment of a second |
| * subscription, Observable returned from `timeoutWith` simply mirrors fallback stream. When that |
| * stream completes, it completes as well. |
| * |
| * Scheduler, which in case of `timeout` is provided as as second argument, can be still provided |
| * here - as a third, optional parameter. It still is used to schedule timeout checks and - |
| * as a consequence - when second Observable will be subscribed, since subscription happens |
| * immediately after failing check. |
| * |
| * ## Example |
| * Add fallback observable |
| * ```ts |
| * import { intrerval } from 'rxjs'; |
| * import { timeoutWith } from 'rxjs/operators'; |
| * |
| * const seconds = interval(1000); |
| * const minutes = interval(60 * 1000); |
| * |
| * seconds.pipe(timeoutWith(900, minutes)) |
| * .subscribe( |
| * value => console.log(value), // After 900ms, will start emitting `minutes`, |
| * // since first value of `seconds` will not arrive fast enough. |
| * err => console.log(err), // Would be called after 900ms in case of `timeout`, |
| * // but here will never be called. |
| * ); |
| * ``` |
| * |
| * @param {number|Date} due Number specifying period within which Observable must emit values |
| * or Date specifying before when Observable should complete |
| * @param {Observable<T>} withObservable Observable which will be subscribed if source fails timeout check. |
| * @param {SchedulerLike} [scheduler] Scheduler controlling when timeout checks occur. |
| * @return {Observable<T>} Observable that mirrors behaviour of source or, when timeout check fails, of an Observable |
| * passed as a second parameter. |
| * @method timeoutWith |
| * @owner Observable |
| */ |
| export function timeoutWith<T, R>(due: number | Date, |
| withObservable: ObservableInput<R>, |
| scheduler: SchedulerLike = async): OperatorFunction<T, T | R> { |
| return (source: Observable<T>) => { |
| let absoluteTimeout = isDate(due); |
| let waitFor = absoluteTimeout ? (+due - scheduler.now()) : Math.abs(<number>due); |
| return source.lift(new TimeoutWithOperator(waitFor, absoluteTimeout, withObservable, scheduler)); |
| }; |
| } |
| |
| class TimeoutWithOperator<T> implements Operator<T, T> { |
| constructor(private waitFor: number, |
| private absoluteTimeout: boolean, |
| private withObservable: ObservableInput<any>, |
| private scheduler: SchedulerLike) { |
| } |
| |
| call(subscriber: Subscriber<T>, source: any): TeardownLogic { |
| return source.subscribe(new TimeoutWithSubscriber( |
| subscriber, this.absoluteTimeout, this.waitFor, this.withObservable, this.scheduler |
| )); |
| } |
| } |
| |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| class TimeoutWithSubscriber<T, R> extends OuterSubscriber<T, R> { |
| |
| private action: SchedulerAction<TimeoutWithSubscriber<T, R>> = null; |
| |
| constructor(destination: Subscriber<T>, |
| private absoluteTimeout: boolean, |
| private waitFor: number, |
| private withObservable: ObservableInput<any>, |
| private scheduler: SchedulerLike) { |
| super(destination); |
| this.scheduleTimeout(); |
| } |
| |
| private static dispatchTimeout<T, R>(subscriber: TimeoutWithSubscriber<T, R>): void { |
| const { withObservable } = subscriber; |
| (<any> subscriber)._unsubscribeAndRecycle(); |
| subscriber.add(subscribeToResult(subscriber, withObservable)); |
| } |
| |
| private scheduleTimeout(): void { |
| const { action } = this; |
| if (action) { |
| // Recycle the action if we've already scheduled one. All the production |
| // Scheduler Actions mutate their state/delay time and return themeselves. |
| // VirtualActions are immutable, so they create and return a clone. In this |
| // case, we need to set the action reference to the most recent VirtualAction, |
| // to ensure that's the one we clone from next time. |
| this.action = (<SchedulerAction<TimeoutWithSubscriber<T, R>>> action.schedule(this, this.waitFor)); |
| } else { |
| this.add(this.action = (<SchedulerAction<TimeoutWithSubscriber<T, R>>> this.scheduler.schedule<TimeoutWithSubscriber<T, R>>( |
| TimeoutWithSubscriber.dispatchTimeout, this.waitFor, this |
| ))); |
| } |
| } |
| |
| protected _next(value: T): void { |
| if (!this.absoluteTimeout) { |
| this.scheduleTimeout(); |
| } |
| super._next(value); |
| } |
| |
| /** @deprecated This is an internal implementation detail, do not use. */ |
| _unsubscribe() { |
| this.action = null; |
| this.scheduler = null; |
| this.withObservable = null; |
| } |
| } |