work.suroh.tk/node_modules/rxjs/operators/debounce.js

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2019-12-02 12:22:45 +00:00
"use strict";
var __extends = (this && this.__extends) || function (d, b) {
for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
var OuterSubscriber_1 = require('../OuterSubscriber');
var subscribeToResult_1 = require('../util/subscribeToResult');
/**
* Emits a value from the source Observable only after a particular time span
* determined by another Observable has passed without another source emission.
*
* <span class="informal">It's like {@link debounceTime}, but the time span of
* emission silence is determined by a second Observable.</span>
*
* <img src="./img/debounce.png" width="100%">
*
* `debounce` delays values emitted by the source Observable, but drops previous
* pending delayed emissions if a new value arrives on the source Observable.
* This operator keeps track of the most recent value from the source
* Observable, and spawns a duration Observable by calling the
* `durationSelector` function. The value is emitted only when the duration
* Observable emits a value or completes, and if no other value was emitted on
* the source Observable since the duration Observable was spawned. If a new
* value appears before the duration Observable emits, the previous value will
* be dropped and will not be emitted on the output Observable.
*
* Like {@link debounceTime}, this is a rate-limiting operator, and also a
* delay-like operator since output emissions do not necessarily occur at the
* same time as they did on the source Observable.
*
* @example <caption>Emit the most recent click after a burst of clicks</caption>
* var clicks = Rx.Observable.fromEvent(document, 'click');
* var result = clicks.debounce(() => Rx.Observable.interval(1000));
* result.subscribe(x => console.log(x));
*
* @see {@link audit}
* @see {@link debounceTime}
* @see {@link delayWhen}
* @see {@link throttle}
*
* @param {function(value: T): SubscribableOrPromise} durationSelector A function
* that receives a value from the source Observable, for computing the timeout
* duration for each source value, returned as an Observable or a Promise.
* @return {Observable} An Observable that delays the emissions of the source
* Observable by the specified duration Observable returned by
* `durationSelector`, and may drop some values if they occur too frequently.
* @method debounce
* @owner Observable
*/
function debounce(durationSelector) {
return function (source) { return source.lift(new DebounceOperator(durationSelector)); };
}
exports.debounce = debounce;
var DebounceOperator = (function () {
function DebounceOperator(durationSelector) {
this.durationSelector = durationSelector;
}
DebounceOperator.prototype.call = function (subscriber, source) {
return source.subscribe(new DebounceSubscriber(subscriber, this.durationSelector));
};
return DebounceOperator;
}());
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
var DebounceSubscriber = (function (_super) {
__extends(DebounceSubscriber, _super);
function DebounceSubscriber(destination, durationSelector) {
_super.call(this, destination);
this.durationSelector = durationSelector;
this.hasValue = false;
this.durationSubscription = null;
}
DebounceSubscriber.prototype._next = function (value) {
try {
var result = this.durationSelector.call(this, value);
if (result) {
this._tryNext(value, result);
}
}
catch (err) {
this.destination.error(err);
}
};
DebounceSubscriber.prototype._complete = function () {
this.emitValue();
this.destination.complete();
};
DebounceSubscriber.prototype._tryNext = function (value, duration) {
var subscription = this.durationSubscription;
this.value = value;
this.hasValue = true;
if (subscription) {
subscription.unsubscribe();
this.remove(subscription);
}
subscription = subscribeToResult_1.subscribeToResult(this, duration);
if (!subscription.closed) {
this.add(this.durationSubscription = subscription);
}
};
DebounceSubscriber.prototype.notifyNext = function (outerValue, innerValue, outerIndex, innerIndex, innerSub) {
this.emitValue();
};
DebounceSubscriber.prototype.notifyComplete = function () {
this.emitValue();
};
DebounceSubscriber.prototype.emitValue = function () {
if (this.hasValue) {
var value = this.value;
var subscription = this.durationSubscription;
if (subscription) {
this.durationSubscription = null;
subscription.unsubscribe();
this.remove(subscription);
}
this.value = null;
this.hasValue = false;
_super.prototype._next.call(this, value);
}
};
return DebounceSubscriber;
}(OuterSubscriber_1.OuterSubscriber));
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