1 import { Observable } from '../Observable';
2 import { OperatorFunction, ObservedValueOf } from '../../internal/types';
3 import { mergeMap } from './mergeMap';
4 import { ObservableInput } from '../types';
6 /* tslint:disable:max-line-length */
7 export function mergeMapTo<T, O extends ObservableInput<any>>(innerObservable: O, concurrent?: number): OperatorFunction<any, ObservedValueOf<O>>;
9 export function mergeMapTo<T, R, O extends ObservableInput<any>>(innerObservable: O, resultSelector: (outerValue: T, innerValue: ObservedValueOf<O>, outerIndex: number, innerIndex: number) => R, concurrent?: number): OperatorFunction<T, R>;
10 /* tslint:enable:max-line-length */
13 * Projects each source value to the same Observable which is merged multiple
14 * times in the output Observable.
16 * <span class="informal">It's like {@link mergeMap}, but maps each value always
17 * to the same inner Observable.</span>
21 * Maps each source value to the given Observable `innerObservable` regardless
22 * of the source value, and then merges those resulting Observables into one
23 * single Observable, which is the output Observable.
26 * For each click event, start an interval Observable ticking every 1 second
28 * import { fromEvent, interval } from 'rxjs';
29 * import { mergeMapTo } from 'rxjs/operators';
31 * const clicks = fromEvent(document, 'click');
32 * const result = clicks.pipe(mergeMapTo(interval(1000)));
33 * result.subscribe(x => console.log(x));
36 * @see {@link concatMapTo}
38 * @see {@link mergeAll}
39 * @see {@link mergeMap}
40 * @see {@link mergeScan}
41 * @see {@link switchMapTo}
43 * @param {ObservableInput} innerObservable An Observable to replace each value from
44 * the source Observable.
45 * @param {number} [concurrent=Number.POSITIVE_INFINITY] Maximum number of input
46 * Observables being subscribed to concurrently.
47 * @return {Observable} An Observable that emits items from the given
52 export function mergeMapTo<T, R, O extends ObservableInput<any>>(
54 resultSelector?: ((outerValue: T, innerValue: ObservedValueOf<O>, outerIndex: number, innerIndex: number) => R) | number,
55 concurrent: number = Number.POSITIVE_INFINITY
56 ): OperatorFunction<T, ObservedValueOf<O>|R> {
57 if (typeof resultSelector === 'function') {
58 return mergeMap(() => innerObservable, resultSelector, concurrent);
60 if (typeof resultSelector === 'number') {
61 concurrent = resultSelector;
63 return mergeMap(() => innerObservable, concurrent);