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91 lines
3.5 KiB
91 lines
3.5 KiB
"use strict"; |
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var __extends = (this && this.__extends) || function (d, b) { |
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for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; |
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function __() { this.constructor = d; } |
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d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __()); |
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}; |
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var Subscriber_1 = require('../Subscriber'); |
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var async_1 = require('../scheduler/async'); |
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/** |
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* Emits the most recently emitted value from the source Observable within |
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* periodic time intervals. |
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* |
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* <span class="informal">Samples the source Observable at periodic time |
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* intervals, emitting what it samples.</span> |
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* |
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* <img src="./img/sampleTime.png" width="100%"> |
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* |
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* `sampleTime` periodically looks at the source Observable and emits whichever |
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* value it has most recently emitted since the previous sampling, unless the |
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* source has not emitted anything since the previous sampling. The sampling |
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* happens periodically in time every `period` milliseconds (or the time unit |
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* defined by the optional `scheduler` argument). The sampling starts as soon as |
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* the output Observable is subscribed. |
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* |
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* @example <caption>Every second, emit the most recent click at most once</caption> |
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* var clicks = Rx.Observable.fromEvent(document, 'click'); |
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* var result = clicks.sampleTime(1000); |
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* result.subscribe(x => console.log(x)); |
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* |
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* @see {@link auditTime} |
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* @see {@link debounceTime} |
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* @see {@link delay} |
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* @see {@link sample} |
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* @see {@link throttleTime} |
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* |
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* @param {number} period The sampling period expressed in milliseconds or the |
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* time unit determined internally by the optional `scheduler`. |
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* @param {Scheduler} [scheduler=async] The {@link IScheduler} to use for |
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* managing the timers that handle the sampling. |
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* @return {Observable<T>} An Observable that emits the results of sampling the |
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* values emitted by the source Observable at the specified time interval. |
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* @method sampleTime |
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* @owner Observable |
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*/ |
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function sampleTime(period, scheduler) { |
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if (scheduler === void 0) { scheduler = async_1.async; } |
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return function (source) { return source.lift(new SampleTimeOperator(period, scheduler)); }; |
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} |
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exports.sampleTime = sampleTime; |
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var SampleTimeOperator = (function () { |
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function SampleTimeOperator(period, scheduler) { |
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this.period = period; |
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this.scheduler = scheduler; |
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} |
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SampleTimeOperator.prototype.call = function (subscriber, source) { |
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return source.subscribe(new SampleTimeSubscriber(subscriber, this.period, this.scheduler)); |
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}; |
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return SampleTimeOperator; |
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}()); |
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/** |
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* We need this JSDoc comment for affecting ESDoc. |
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* @ignore |
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* @extends {Ignored} |
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*/ |
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var SampleTimeSubscriber = (function (_super) { |
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__extends(SampleTimeSubscriber, _super); |
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function SampleTimeSubscriber(destination, period, scheduler) { |
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_super.call(this, destination); |
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this.period = period; |
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this.scheduler = scheduler; |
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this.hasValue = false; |
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this.add(scheduler.schedule(dispatchNotification, period, { subscriber: this, period: period })); |
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} |
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SampleTimeSubscriber.prototype._next = function (value) { |
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this.lastValue = value; |
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this.hasValue = true; |
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}; |
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SampleTimeSubscriber.prototype.notifyNext = function () { |
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if (this.hasValue) { |
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this.hasValue = false; |
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this.destination.next(this.lastValue); |
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} |
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}; |
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return SampleTimeSubscriber; |
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}(Subscriber_1.Subscriber)); |
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function dispatchNotification(state) { |
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var subscriber = state.subscriber, period = state.period; |
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subscriber.notifyNext(); |
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this.schedule(state, period); |
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} |
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//# sourceMappingURL=sampleTime.js.map
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