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- import { async } from '../scheduler/async';
- import { isDate } from '../util/isDate';
- import { Subscriber } from '../Subscriber';
- import { Notification } from '../Notification';
- /**
- * Delays the emission of items from the source Observable by a given timeout or
- * until a given Date.
- *
- * <span class="informal">Time shifts each item by some specified amount of
- * milliseconds.</span>
- *
- * <img src="./img/delay.png" width="100%">
- *
- * If the delay argument is a Number, this operator time shifts the source
- * Observable by that amount of time expressed in milliseconds. The relative
- * time intervals between the values are preserved.
- *
- * If the delay argument is a Date, this operator time shifts the start of the
- * Observable execution until the given date occurs.
- *
- * @example <caption>Delay each click by one second</caption>
- * var clicks = Rx.Observable.fromEvent(document, 'click');
- * var delayedClicks = clicks.delay(1000); // each click emitted after 1 second
- * delayedClicks.subscribe(x => console.log(x));
- *
- * @example <caption>Delay all clicks until a future date happens</caption>
- * var clicks = Rx.Observable.fromEvent(document, 'click');
- * var date = new Date('March 15, 2050 12:00:00'); // in the future
- * var delayedClicks = clicks.delay(date); // click emitted only after that date
- * delayedClicks.subscribe(x => console.log(x));
- *
- * @see {@link debounceTime}
- * @see {@link delayWhen}
- *
- * @param {number|Date} delay The delay duration in milliseconds (a `number`) or
- * a `Date` until which the emission of the source items is delayed.
- * @param {Scheduler} [scheduler=async] The IScheduler to use for
- * managing the timers that handle the time-shift for each item.
- * @return {Observable} An Observable that delays the emissions of the source
- * Observable by the specified timeout or Date.
- * @method delay
- * @owner Observable
- */
- export function delay(delay, scheduler = async) {
- const absoluteDelay = isDate(delay);
- const delayFor = absoluteDelay ? (+delay - scheduler.now()) : Math.abs(delay);
- return (source) => source.lift(new DelayOperator(delayFor, scheduler));
- }
- class DelayOperator {
- constructor(delay, scheduler) {
- this.delay = delay;
- this.scheduler = scheduler;
- }
- call(subscriber, source) {
- return source.subscribe(new DelaySubscriber(subscriber, this.delay, this.scheduler));
- }
- }
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- class DelaySubscriber extends Subscriber {
- constructor(destination, delay, scheduler) {
- super(destination);
- this.delay = delay;
- this.scheduler = scheduler;
- this.queue = [];
- this.active = false;
- this.errored = false;
- }
- static dispatch(state) {
- const source = state.source;
- const queue = source.queue;
- const scheduler = state.scheduler;
- const destination = state.destination;
- while (queue.length > 0 && (queue[0].time - scheduler.now()) <= 0) {
- queue.shift().notification.observe(destination);
- }
- if (queue.length > 0) {
- const delay = Math.max(0, queue[0].time - scheduler.now());
- this.schedule(state, delay);
- }
- else {
- this.unsubscribe();
- source.active = false;
- }
- }
- _schedule(scheduler) {
- this.active = true;
- this.add(scheduler.schedule(DelaySubscriber.dispatch, this.delay, {
- source: this, destination: this.destination, scheduler: scheduler
- }));
- }
- scheduleNotification(notification) {
- if (this.errored === true) {
- return;
- }
- const scheduler = this.scheduler;
- const message = new DelayMessage(scheduler.now() + this.delay, notification);
- this.queue.push(message);
- if (this.active === false) {
- this._schedule(scheduler);
- }
- }
- _next(value) {
- this.scheduleNotification(Notification.createNext(value));
- }
- _error(err) {
- this.errored = true;
- this.queue = [];
- this.destination.error(err);
- }
- _complete() {
- this.scheduleNotification(Notification.createComplete());
- }
- }
- class DelayMessage {
- constructor(time, notification) {
- this.time = time;
- this.notification = notification;
- }
- }
- //# sourceMappingURL=delay.js.map
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