import { Observable } from '../Observable'; import { Subject } from '../Subject'; import { multicast } from './multicast'; import { ConnectableObservable } from '../observable/ConnectableObservable'; import { MonoTypeOperatorFunction, OperatorFunction, UnaryFunction, ObservableInput, ObservedValueOf } from '../types'; /* tslint:disable:max-line-length */ export function publish<T>(): UnaryFunction<Observable<T>, ConnectableObservable<T>>; export function publish<T, O extends ObservableInput<any>>(selector: (shared: Observable<T>) => O): OperatorFunction<T, ObservedValueOf<O>>; export function publish<T>(selector: MonoTypeOperatorFunction<T>): MonoTypeOperatorFunction<T>; /* tslint:enable:max-line-length */ /** * Returns a ConnectableObservable, which is a variety of Observable that waits until its connect method is called * before it begins emitting items to those Observers that have subscribed to it. * * <span class="informal">Makes a cold Observable hot</span> * *  * * ## Examples * Make source$ hot by applying publish operator, then merge each inner observable into a single one * and subscribe. * ```ts * import { of, zip, interval, merge } from "rxjs"; * import { map, publish, tap } from "rxjs/operators"; * * const source$ = zip(interval(2000), of(1, 2, 3, 4, 5, 6, 7, 8, 9)).pipe( * map(values => values[1]) * ); * * source$ * .pipe( * publish(multicasted$ => * merge( * multicasted$.pipe(tap(x => console.log('Stream 1:', x))), * multicasted$.pipe(tap(x => console.log('Stream 2:', x))), * multicasted$.pipe(tap(x => console.log('Stream 3:', x))), * ) * ) * ) * .subscribe(); * * // Results every two seconds * // Stream 1: 1 * // Stream 2: 1 * // Stream 3: 1 * // ... * // Stream 1: 9 * // Stream 2: 9 * // Stream 3: 9 * ``` * * @param {Function} [selector] - Optional selector function which can use the multicasted source sequence as many times * as needed, without causing multiple subscriptions to the source sequence. * Subscribers to the given source will receive all notifications of the source from the time of the subscription on. * @return A ConnectableObservable that upon connection causes the source Observable to emit items to its Observers. * @method publish * @owner Observable * * */ export function publish<T, R>(selector?: OperatorFunction<T, R>): MonoTypeOperatorFunction<T> | OperatorFunction<T, R> { return selector ? multicast(() => new Subject<T>(), selector) : multicast(new Subject<T>()); }