Opal-Estate-Pro/node_modules/rxjs/_esm2015/operators/delay.js
2019-09-13 11:27:52 +07:00

124 lines
4.3 KiB
JavaScript
Executable File

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;
}
}
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