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- import { OuterSubscriber } from '../OuterSubscriber';
- import { subscribeToResult } from '../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
- */
- export function debounce(durationSelector) {
- return (source) => source.lift(new DebounceOperator(durationSelector));
- }
- class DebounceOperator {
- constructor(durationSelector) {
- this.durationSelector = durationSelector;
- }
- call(subscriber, source) {
- return source.subscribe(new DebounceSubscriber(subscriber, this.durationSelector));
- }
- }
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- class DebounceSubscriber extends OuterSubscriber {
- constructor(destination, durationSelector) {
- super(destination);
- this.durationSelector = durationSelector;
- this.hasValue = false;
- this.durationSubscription = null;
- }
- _next(value) {
- try {
- const result = this.durationSelector.call(this, value);
- if (result) {
- this._tryNext(value, result);
- }
- }
- catch (err) {
- this.destination.error(err);
- }
- }
- _complete() {
- this.emitValue();
- this.destination.complete();
- }
- _tryNext(value, duration) {
- let subscription = this.durationSubscription;
- this.value = value;
- this.hasValue = true;
- if (subscription) {
- subscription.unsubscribe();
- this.remove(subscription);
- }
- subscription = subscribeToResult(this, duration);
- if (!subscription.closed) {
- this.add(this.durationSubscription = subscription);
- }
- }
- notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) {
- this.emitValue();
- }
- notifyComplete() {
- this.emitValue();
- }
- emitValue() {
- if (this.hasValue) {
- const value = this.value;
- const subscription = this.durationSubscription;
- if (subscription) {
- this.durationSubscription = null;
- subscription.unsubscribe();
- this.remove(subscription);
- }
- this.value = null;
- this.hasValue = false;
- super._next(value);
- }
- }
- }
- //# sourceMappingURL=debounce.js.map
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