1import { Observable } from '../Observable';
2import { Subject } from '../Subject';
3import { multicast } from './multicast';
4import { ConnectableObservable } from '../observable/ConnectableObservable';
5import { MonoTypeOperatorFunction, OperatorFunction, UnaryFunction, ObservableInput, ObservedValueOf } from '../types';
6
7/* tslint:disable:max-line-length */
8export function publish<T>(): UnaryFunction<Observable<T>, ConnectableObservable<T>>;
9export function publish<T, O extends ObservableInput<any>>(selector: (shared: Observable<T>) => O): OperatorFunction<T, ObservedValueOf<O>>;
10export function publish<T>(selector: MonoTypeOperatorFunction<T>): MonoTypeOperatorFunction<T>;
11/* tslint:enable:max-line-length */
12
13/**
14 * Returns a ConnectableObservable, which is a variety of Observable that waits until its connect method is called
15 * before it begins emitting items to those Observers that have subscribed to it.
16 *
17 * <span class="informal">Makes a cold Observable hot</span>
18 *
19 * ![](publish.png)
20 *
21 * ## Examples
22 * Make source$ hot by applying publish operator, then merge each inner observable into a single one
23 * and subscribe.
24 * ```ts
25 * import { of, zip, interval, merge } from "rxjs";
26 * import { map, publish, tap } from "rxjs/operators";
27 *
28 * const source$ = zip(interval(2000), of(1, 2, 3, 4, 5, 6, 7, 8, 9)).pipe(
29 *   map(values => values[1])
30 * );
31 *
32 * source$
33 *   .pipe(
34 *     publish(multicasted$ =>
35 *       merge(
36 *         multicasted$.pipe(tap(x => console.log('Stream 1:', x))),
37 *         multicasted$.pipe(tap(x => console.log('Stream 2:', x))),
38 *         multicasted$.pipe(tap(x => console.log('Stream 3:', x))),
39 *       )
40 *     )
41 *   )
42 *   .subscribe();
43 *
44 * // Results every two seconds
45 * // Stream 1: 1
46 * // Stream 2: 1
47 * // Stream 3: 1
48 * // ...
49 * // Stream 1: 9
50 * // Stream 2: 9
51 * // Stream 3: 9
52 * ```
53 *
54 * @param {Function} [selector] - Optional selector function which can use the multicasted source sequence as many times
55 * as needed, without causing multiple subscriptions to the source sequence.
56 * Subscribers to the given source will receive all notifications of the source from the time of the subscription on.
57 * @return A ConnectableObservable that upon connection causes the source Observable to emit items to its Observers.
58 * @method publish
59 * @owner Observable
60 *
61 *
62 */
63export function publish<T, R>(selector?: OperatorFunction<T, R>): MonoTypeOperatorFunction<T> | OperatorFunction<T, R> {
64  return selector ?
65    multicast(() => new Subject<T>(), selector) :
66    multicast(new Subject<T>());
67}
68