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- /** PURE_IMPORTS_START .._OuterSubscriber,.._util_subscribeToResult PURE_IMPORTS_END */
- 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 __());
- };
- import { OuterSubscriber } from '../OuterSubscriber';
- import { subscribeToResult } from '../util/subscribeToResult';
- /* tslint:enable:max-line-length */
- /**
- * Projects each source value to an Observable which is merged in the output
- * Observable only if the previous projected Observable has completed.
- *
- * <span class="informal">Maps each value to an Observable, then flattens all of
- * these inner Observables using {@link exhaust}.</span>
- *
- * <img src="./img/exhaustMap.png" width="100%">
- *
- * Returns an Observable that emits items based on applying a function that you
- * supply to each item emitted by the source Observable, where that function
- * returns an (so-called "inner") Observable. When it projects a source value to
- * an Observable, the output Observable begins emitting the items emitted by
- * that projected Observable. However, `exhaustMap` ignores every new projected
- * Observable if the previous projected Observable has not yet completed. Once
- * that one completes, it will accept and flatten the next projected Observable
- * and repeat this process.
- *
- * @example <caption>Run a finite timer for each click, only if there is no currently active timer</caption>
- * var clicks = Rx.Observable.fromEvent(document, 'click');
- * var result = clicks.exhaustMap((ev) => Rx.Observable.interval(1000).take(5));
- * result.subscribe(x => console.log(x));
- *
- * @see {@link concatMap}
- * @see {@link exhaust}
- * @see {@link mergeMap}
- * @see {@link switchMap}
- *
- * @param {function(value: T, ?index: number): ObservableInput} project A function
- * that, when applied to an item emitted by the source Observable, returns an
- * Observable.
- * @param {function(outerValue: T, innerValue: I, outerIndex: number, innerIndex: number): any} [resultSelector]
- * A function to produce the value on the output Observable based on the values
- * and the indices of the source (outer) emission and the inner Observable
- * emission. The arguments passed to this function are:
- * - `outerValue`: the value that came from the source
- * - `innerValue`: the value that came from the projected Observable
- * - `outerIndex`: the "index" of the value that came from the source
- * - `innerIndex`: the "index" of the value from the projected Observable
- * @return {Observable} An Observable containing projected Observables
- * of each item of the source, ignoring projected Observables that start before
- * their preceding Observable has completed.
- * @method exhaustMap
- * @owner Observable
- */
- export function exhaustMap(project, resultSelector) {
- return function (source) { return source.lift(new SwitchFirstMapOperator(project, resultSelector)); };
- }
- var SwitchFirstMapOperator = /*@__PURE__*/ (/*@__PURE__*/ function () {
- function SwitchFirstMapOperator(project, resultSelector) {
- this.project = project;
- this.resultSelector = resultSelector;
- }
- SwitchFirstMapOperator.prototype.call = function (subscriber, source) {
- return source.subscribe(new SwitchFirstMapSubscriber(subscriber, this.project, this.resultSelector));
- };
- return SwitchFirstMapOperator;
- }());
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- var SwitchFirstMapSubscriber = /*@__PURE__*/ (/*@__PURE__*/ function (_super) {
- __extends(SwitchFirstMapSubscriber, _super);
- function SwitchFirstMapSubscriber(destination, project, resultSelector) {
- _super.call(this, destination);
- this.project = project;
- this.resultSelector = resultSelector;
- this.hasSubscription = false;
- this.hasCompleted = false;
- this.index = 0;
- }
- SwitchFirstMapSubscriber.prototype._next = function (value) {
- if (!this.hasSubscription) {
- this.tryNext(value);
- }
- };
- SwitchFirstMapSubscriber.prototype.tryNext = function (value) {
- var index = this.index++;
- var destination = this.destination;
- try {
- var result = this.project(value, index);
- this.hasSubscription = true;
- this.add(subscribeToResult(this, result, value, index));
- }
- catch (err) {
- destination.error(err);
- }
- };
- SwitchFirstMapSubscriber.prototype._complete = function () {
- this.hasCompleted = true;
- if (!this.hasSubscription) {
- this.destination.complete();
- }
- };
- SwitchFirstMapSubscriber.prototype.notifyNext = function (outerValue, innerValue, outerIndex, innerIndex, innerSub) {
- var _a = this, resultSelector = _a.resultSelector, destination = _a.destination;
- if (resultSelector) {
- this.trySelectResult(outerValue, innerValue, outerIndex, innerIndex);
- }
- else {
- destination.next(innerValue);
- }
- };
- SwitchFirstMapSubscriber.prototype.trySelectResult = function (outerValue, innerValue, outerIndex, innerIndex) {
- var _a = this, resultSelector = _a.resultSelector, destination = _a.destination;
- try {
- var result = resultSelector(outerValue, innerValue, outerIndex, innerIndex);
- destination.next(result);
- }
- catch (err) {
- destination.error(err);
- }
- };
- SwitchFirstMapSubscriber.prototype.notifyError = function (err) {
- this.destination.error(err);
- };
- SwitchFirstMapSubscriber.prototype.notifyComplete = function (innerSub) {
- this.remove(innerSub);
- this.hasSubscription = false;
- if (this.hasCompleted) {
- this.destination.complete();
- }
- };
- return SwitchFirstMapSubscriber;
- }(OuterSubscriber));
- //# sourceMappingURL=exhaustMap.js.map
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