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- import { OuterSubscriber } from '../OuterSubscriber';
- import { subscribeToResult } from '../util/subscribeToResult';
- /* tslint:enable:max-line-length */
- /**
- * Projects each source value to the same Observable which is merged multiple
- * times in the output Observable.
- *
- * <span class="informal">It's like {@link mergeMap}, but maps each value always
- * to the same inner Observable.</span>
- *
- * <img src="./img/mergeMapTo.png" width="100%">
- *
- * Maps each source value to the given Observable `innerObservable` regardless
- * of the source value, and then merges those resulting Observables into one
- * single Observable, which is the output Observable.
- *
- * @example <caption>For each click event, start an interval Observable ticking every 1 second</caption>
- * var clicks = Rx.Observable.fromEvent(document, 'click');
- * var result = clicks.mergeMapTo(Rx.Observable.interval(1000));
- * result.subscribe(x => console.log(x));
- *
- * @see {@link concatMapTo}
- * @see {@link merge}
- * @see {@link mergeAll}
- * @see {@link mergeMap}
- * @see {@link mergeScan}
- * @see {@link switchMapTo}
- *
- * @param {ObservableInput} innerObservable An Observable to replace each value from
- * the source 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
- * @param {number} [concurrent=Number.POSITIVE_INFINITY] Maximum number of input
- * Observables being subscribed to concurrently.
- * @return {Observable} An Observable that emits items from the given
- * `innerObservable` (and optionally transformed through `resultSelector`) every
- * time a value is emitted on the source Observable.
- * @method mergeMapTo
- * @owner Observable
- */
- export function mergeMapTo(innerObservable, resultSelector, concurrent = Number.POSITIVE_INFINITY) {
- if (typeof resultSelector === 'number') {
- concurrent = resultSelector;
- resultSelector = null;
- }
- return (source) => source.lift(new MergeMapToOperator(innerObservable, resultSelector, concurrent));
- }
- // TODO: Figure out correct signature here: an Operator<Observable<T>, R>
- // needs to implement call(observer: Subscriber<R>): Subscriber<Observable<T>>
- export class MergeMapToOperator {
- constructor(ish, resultSelector, concurrent = Number.POSITIVE_INFINITY) {
- this.ish = ish;
- this.resultSelector = resultSelector;
- this.concurrent = concurrent;
- }
- call(observer, source) {
- return source.subscribe(new MergeMapToSubscriber(observer, this.ish, this.resultSelector, this.concurrent));
- }
- }
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- export class MergeMapToSubscriber extends OuterSubscriber {
- constructor(destination, ish, resultSelector, concurrent = Number.POSITIVE_INFINITY) {
- super(destination);
- this.ish = ish;
- this.resultSelector = resultSelector;
- this.concurrent = concurrent;
- this.hasCompleted = false;
- this.buffer = [];
- this.active = 0;
- this.index = 0;
- }
- _next(value) {
- if (this.active < this.concurrent) {
- const resultSelector = this.resultSelector;
- const index = this.index++;
- const ish = this.ish;
- const destination = this.destination;
- this.active++;
- this._innerSub(ish, destination, resultSelector, value, index);
- }
- else {
- this.buffer.push(value);
- }
- }
- _innerSub(ish, destination, resultSelector, value, index) {
- this.add(subscribeToResult(this, ish, value, index));
- }
- _complete() {
- this.hasCompleted = true;
- if (this.active === 0 && this.buffer.length === 0) {
- this.destination.complete();
- }
- }
- notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) {
- const { resultSelector, destination } = this;
- if (resultSelector) {
- this.trySelectResult(outerValue, innerValue, outerIndex, innerIndex);
- }
- else {
- destination.next(innerValue);
- }
- }
- trySelectResult(outerValue, innerValue, outerIndex, innerIndex) {
- const { resultSelector, destination } = this;
- let result;
- try {
- result = resultSelector(outerValue, innerValue, outerIndex, innerIndex);
- }
- catch (err) {
- destination.error(err);
- return;
- }
- destination.next(result);
- }
- notifyError(err) {
- this.destination.error(err);
- }
- notifyComplete(innerSub) {
- const buffer = this.buffer;
- this.remove(innerSub);
- this.active--;
- if (buffer.length > 0) {
- this._next(buffer.shift());
- }
- else if (this.active === 0 && this.hasCompleted) {
- this.destination.complete();
- }
- }
- }
- //# sourceMappingURL=mergeMapTo.js.map
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