76 lines
3.0 KiB
JavaScript
76 lines
3.0 KiB
JavaScript
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"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 OuterSubscriber_1 = require('../OuterSubscriber');
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var subscribeToResult_1 = require('../util/subscribeToResult');
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/**
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* Converts an Observable that emits Observables into an Observable that emits the items emitted by the most recently
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* emitted of those Observables.
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*
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* <img src="./img/switch.png" width="100%">
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*
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* Switch subscribes to an Observable that emits Observables. Each time it observes one of these emitted Observables,
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* the Observable returned by switchOnNext begins emitting the items emitted by that Observable. When a new Observable
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* is emitted, switchOnNext stops emitting items from the earlier-emitted Observable and begins emitting items from the
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* new one.
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*
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* @param {Function} a predicate function to evaluate items emitted by the source Observable.
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* @returns {Observable<T>} an Observable that emits the items emitted by the Observable most recently emitted by the
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* source Observable.
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*/
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function _switch() {
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return this.lift(new SwitchOperator());
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}
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exports._switch = _switch;
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var SwitchOperator = (function () {
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function SwitchOperator() {
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}
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SwitchOperator.prototype.call = function (subscriber) {
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return new SwitchSubscriber(subscriber);
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};
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return SwitchOperator;
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}());
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var SwitchSubscriber = (function (_super) {
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__extends(SwitchSubscriber, _super);
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function SwitchSubscriber(destination) {
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_super.call(this, destination);
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this.active = 0;
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this.hasCompleted = false;
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}
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SwitchSubscriber.prototype._next = function (value) {
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this.unsubscribeInner();
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this.active++;
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this.add(this.innerSubscription = subscribeToResult_1.subscribeToResult(this, value));
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};
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SwitchSubscriber.prototype._complete = function () {
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this.hasCompleted = true;
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if (this.active === 0) {
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this.destination.complete();
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}
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};
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SwitchSubscriber.prototype.unsubscribeInner = function () {
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this.active = this.active > 0 ? this.active - 1 : 0;
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var innerSubscription = this.innerSubscription;
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if (innerSubscription) {
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innerSubscription.unsubscribe();
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this.remove(innerSubscription);
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}
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};
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SwitchSubscriber.prototype.notifyNext = function (outerValue, innerValue, outerIndex, innerIndex, innerSub) {
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this.destination.next(innerValue);
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};
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SwitchSubscriber.prototype.notifyError = function (err) {
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this.destination.error(err);
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};
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SwitchSubscriber.prototype.notifyComplete = function () {
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this.unsubscribeInner();
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if (this.hasCompleted && this.active === 0) {
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this.destination.complete();
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}
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};
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return SwitchSubscriber;
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}(OuterSubscriber_1.OuterSubscriber));
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//# sourceMappingURL=switch.js.map
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