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- import { Observable } from '../Observable';
- import { ObservableInput, ObservedValuesFromArray, ObservedValueOf, SubscribableOrPromise } from '../types';
- import { isArray } from '../util/isArray';
- import { map } from '../operators/map';
- import { isObject } from '../util/isObject';
- import { isObservable } from '../util/isObservable';
- import { from } from './from';
- /* tslint:disable:max-line-length */
- // forkJoin(a$, b$, c$)
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T>(v1: SubscribableOrPromise<T>): Observable<[T]>;
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T, T2>(v1: ObservableInput<T>, v2: ObservableInput<T2>): Observable<[T, T2]>;
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T, T2, T3>(v1: ObservableInput<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>): Observable<[T, T2, T3]>;
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T, T2, T3, T4>(v1: ObservableInput<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>): Observable<[T, T2, T3, T4]>;
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T, T2, T3, T4, T5>(v1: ObservableInput<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>): Observable<[T, T2, T3, T4, T5]>;
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T, T2, T3, T4, T5, T6>(v1: ObservableInput<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>): Observable<[T, T2, T3, T4, T5, T6]>;
- // forkJoin([a$, b$, c$]);
- // TODO(benlesh): Uncomment for TS 3.0
- // export function forkJoin(sources: []): Observable<never>;
- export function forkJoin<A>(sources: [ObservableInput<A>]): Observable<[A]>;
- export function forkJoin<A, B>(sources: [ObservableInput<A>, ObservableInput<B>]): Observable<[A, B]>;
- export function forkJoin<A, B, C>(sources: [ObservableInput<A>, ObservableInput<B>, ObservableInput<C>]): Observable<[A, B, C]>;
- export function forkJoin<A, B, C, D>(sources: [ObservableInput<A>, ObservableInput<B>, ObservableInput<C>, ObservableInput<D>]): Observable<[A, B, C, D]>;
- export function forkJoin<A, B, C, D, E>(sources: [ObservableInput<A>, ObservableInput<B>, ObservableInput<C>, ObservableInput<D>, ObservableInput<E>]): Observable<[A, B, C, D, E]>;
- export function forkJoin<A, B, C, D, E, F>(sources: [ObservableInput<A>, ObservableInput<B>, ObservableInput<C>, ObservableInput<D>, ObservableInput<E>, ObservableInput<F>]): Observable<[A, B, C, D, E, F]>;
- export function forkJoin<A extends ObservableInput<any>[]>(sources: A): Observable<ObservedValuesFromArray<A>[]>;
- // forkJoin({})
- export function forkJoin(sourcesObject: {}): Observable<never>;
- export function forkJoin<T, K extends keyof T>(sourcesObject: T): Observable<{ [K in keyof T]: ObservedValueOf<T[K]> }>;
- /** @deprecated resultSelector is deprecated, pipe to map instead */
- export function forkJoin(...args: Array<ObservableInput<any>|Function>): Observable<any>;
- /** @deprecated Use the version that takes an array of Observables instead */
- export function forkJoin<T>(...sources: ObservableInput<T>[]): Observable<T[]>;
- /* tslint:enable:max-line-length */
- /**
- * Accepts an `Array` of {@link ObservableInput} or a dictionary `Object` of {@link ObservableInput} and returns
- * an {@link Observable} that emits either an array of values in the exact same order as the passed array,
- * or a dictionary of values in the same shape as the passed dictionary.
- *
- * <span class="informal">Wait for Observables to complete and then combine last values they emitted.</span>
- *
- * 
- *
- * `forkJoin` is an operator that takes any number of input observables which can be passed either as an array
- * or a dictionary of input observables. If no input observables are provided, resulting stream will complete
- * immediately.
- *
- * `forkJoin` will wait for all passed observables to complete and then it will emit an array or an object with last
- * values from corresponding observables.
- *
- * If you pass an array of `n` observables to the operator, resulting
- * array will have `n` values, where first value is the last thing emitted by the first observable,
- * second value is the last thing emitted by the second observable and so on.
- *
- * If you pass a dictionary of observables to the operator, resulting
- * objects will have the same keys as the dictionary passed, with their last values they've emitted
- * located at the corresponding key.
- *
- * That means `forkJoin` will not emit more than once and it will complete after that. If you need to emit combined
- * values not only at the end of lifecycle of passed observables, but also throughout it, try out {@link combineLatest}
- * or {@link zip} instead.
- *
- * In order for resulting array to have the same length as the number of input observables, whenever any of
- * that observables completes without emitting any value, `forkJoin` will complete at that moment as well
- * and it will not emit anything either, even if it already has some last values from other observables.
- * Conversely, if there is an observable that never completes, `forkJoin` will never complete as well,
- * unless at any point some other observable completes without emitting value, which brings us back to
- * the previous case. Overall, in order for `forkJoin` to emit a value, all observables passed as arguments
- * have to emit something at least once and complete.
- *
- * If any input observable errors at some point, `forkJoin` will error as well and all other observables
- * will be immediately unsubscribed.
- *
- * Optionally `forkJoin` accepts project function, that will be called with values which normally
- * would land in emitted array. Whatever is returned by project function, will appear in output
- * observable instead. This means that default project can be thought of as a function that takes
- * all its arguments and puts them into an array. Note that project function will be called only
- * when output observable is supposed to emit a result.
- *
- * ## Examples
- *
- * ### Use forkJoin with a dictionary of observable inputs
- * ```ts
- * import { forkJoin, of, timer } from 'rxjs';
- *
- * const observable = forkJoin({
- * foo: of(1, 2, 3, 4),
- * bar: Promise.resolve(8),
- * baz: timer(4000),
- * });
- * observable.subscribe({
- * next: value => console.log(value),
- * complete: () => console.log('This is how it ends!'),
- * });
- *
- * // Logs:
- * // { foo: 4, bar: 8, baz: 0 } after 4 seconds
- * // "This is how it ends!" immediately after
- * ```
- *
- * ### Use forkJoin with an array of observable inputs
- * ```ts
- * import { forkJoin, of } from 'rxjs';
- *
- * const observable = forkJoin([
- * of(1, 2, 3, 4),
- * Promise.resolve(8),
- * timer(4000),
- * ]);
- * observable.subscribe({
- * next: value => console.log(value),
- * complete: () => console.log('This is how it ends!'),
- * });
- *
- * // Logs:
- * // [4, 8, 0] after 4 seconds
- * // "This is how it ends!" immediately after
- * ```
- *
- * @see {@link combineLatest}
- * @see {@link zip}
- *
- * @param {...ObservableInput} sources Any number of Observables provided either as an array or as an arguments
- * passed directly to the operator.
- * @param {function} [project] Function that takes values emitted by input Observables and returns value
- * that will appear in resulting Observable instead of default array.
- * @return {Observable} Observable emitting either an array of last values emitted by passed Observables
- * or value from project function.
- */
- export function forkJoin(
- ...sources: any[]
- ): Observable<any> {
- if (sources.length === 1) {
- const first = sources[0];
- if (isArray(first)) {
- return forkJoinInternal(first, null);
- }
- // TODO(benlesh): isObservable check will not be necessary when deprecated path is removed.
- if (isObject(first) && Object.getPrototypeOf(first) === Object.prototype) {
- const keys = Object.keys(first);
- return forkJoinInternal(keys.map(key => first[key]), keys);
- }
- }
- // DEPRECATED PATHS BELOW HERE
- if (typeof sources[sources.length - 1] === 'function') {
- const resultSelector = sources.pop() as Function;
- sources = (sources.length === 1 && isArray(sources[0])) ? sources[0] : sources;
- return forkJoinInternal(sources, null).pipe(
- map((args: any[]) => resultSelector(...args))
- );
- }
- return forkJoinInternal(sources, null);
- }
- function forkJoinInternal(sources: ObservableInput<any>[], keys: string[] | null): Observable<any> {
- return new Observable(subscriber => {
- const len = sources.length;
- if (len === 0) {
- subscriber.complete();
- return;
- }
- const values = new Array(len);
- let completed = 0;
- let emitted = 0;
- for (let i = 0; i < len; i++) {
- const source = from(sources[i]);
- let hasValue = false;
- subscriber.add(source.subscribe({
- next: value => {
- if (!hasValue) {
- hasValue = true;
- emitted++;
- }
- values[i] = value;
- },
- error: err => subscriber.error(err),
- complete: () => {
- completed++;
- if (completed === len || !hasValue) {
- if (emitted === len) {
- subscriber.next(keys ?
- keys.reduce((result, key, i) => (result[key] = values[i], result), {}) :
- values);
- }
- subscriber.complete();
- }
- }
- }));
- }
- });
- }
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