1import { Observable } from '../Observable'; 2import { OperatorFunction, ObservedValueOf } from '../../internal/types'; 3import { mergeMap } from './mergeMap'; 4import { ObservableInput } from '../types'; 5 6/* tslint:disable:max-line-length */ 7export function mergeMapTo<T, O extends ObservableInput<any>>(innerObservable: O, concurrent?: number): OperatorFunction<any, ObservedValueOf<O>>; 8/** @deprecated */ 9export 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 */ 11 12/** 13 * Projects each source value to the same Observable which is merged multiple 14 * times in the output Observable. 15 * 16 * <span class="informal">It's like {@link mergeMap}, but maps each value always 17 * to the same inner Observable.</span> 18 * 19 * ![](mergeMapTo.png) 20 * 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. 24 * 25 * ## Example 26 * For each click event, start an interval Observable ticking every 1 second 27 * ```ts 28 * import { fromEvent, interval } from 'rxjs'; 29 * import { mergeMapTo } from 'rxjs/operators'; 30 * 31 * const clicks = fromEvent(document, 'click'); 32 * const result = clicks.pipe(mergeMapTo(interval(1000))); 33 * result.subscribe(x => console.log(x)); 34 * ``` 35 * 36 * @see {@link concatMapTo} 37 * @see {@link merge} 38 * @see {@link mergeAll} 39 * @see {@link mergeMap} 40 * @see {@link mergeScan} 41 * @see {@link switchMapTo} 42 * 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 48 * `innerObservable` 49 * @method mergeMapTo 50 * @owner Observable 51 */ 52export function mergeMapTo<T, R, O extends ObservableInput<any>>( 53 innerObservable: O, 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); 59 } 60 if (typeof resultSelector === 'number') { 61 concurrent = resultSelector; 62 } 63 return mergeMap(() => innerObservable, concurrent); 64} 65