117 lines
5.3 KiB
JavaScript
Executable File
117 lines
5.3 KiB
JavaScript
Executable File
import { async } from '../scheduler/async';
|
|
import { isDate } from '../util/isDate';
|
|
import { OuterSubscriber } from '../OuterSubscriber';
|
|
import { subscribeToResult } from '../util/subscribeToResult';
|
|
/* 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>
|
|
*
|
|
* <img src="./img/timeoutWith.png" width="100%">
|
|
*
|
|
* `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 <caption>Add fallback observable</caption>
|
|
* const seconds = Rx.Observable.interval(1000);
|
|
* const minutes = Rx.Observable.interval(60 * 1000);
|
|
*
|
|
* seconds.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 {Scheduler} [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(due, withObservable, scheduler = async) {
|
|
return (source) => {
|
|
let absoluteTimeout = isDate(due);
|
|
let waitFor = absoluteTimeout ? (+due - scheduler.now()) : Math.abs(due);
|
|
return source.lift(new TimeoutWithOperator(waitFor, absoluteTimeout, withObservable, scheduler));
|
|
};
|
|
}
|
|
class TimeoutWithOperator {
|
|
constructor(waitFor, absoluteTimeout, withObservable, scheduler) {
|
|
this.waitFor = waitFor;
|
|
this.absoluteTimeout = absoluteTimeout;
|
|
this.withObservable = withObservable;
|
|
this.scheduler = scheduler;
|
|
}
|
|
call(subscriber, source) {
|
|
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 extends OuterSubscriber {
|
|
constructor(destination, absoluteTimeout, waitFor, withObservable, scheduler) {
|
|
super(destination);
|
|
this.absoluteTimeout = absoluteTimeout;
|
|
this.waitFor = waitFor;
|
|
this.withObservable = withObservable;
|
|
this.scheduler = scheduler;
|
|
this.action = null;
|
|
this.scheduleTimeout();
|
|
}
|
|
static dispatchTimeout(subscriber) {
|
|
const { withObservable } = subscriber;
|
|
subscriber._unsubscribeAndRecycle();
|
|
subscriber.add(subscribeToResult(subscriber, withObservable));
|
|
}
|
|
scheduleTimeout() {
|
|
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 = action.schedule(this, this.waitFor);
|
|
}
|
|
else {
|
|
this.add(this.action = this.scheduler.schedule(TimeoutWithSubscriber.dispatchTimeout, this.waitFor, this));
|
|
}
|
|
}
|
|
_next(value) {
|
|
if (!this.absoluteTimeout) {
|
|
this.scheduleTimeout();
|
|
}
|
|
super._next(value);
|
|
}
|
|
/** @deprecated internal use only */ _unsubscribe() {
|
|
this.action = null;
|
|
this.scheduler = null;
|
|
this.withObservable = null;
|
|
}
|
|
}
|
|
//# sourceMappingURL=timeoutWith.js.map
|