| 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.png) |
| * |
| * `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(); |
| } |
| } |
| })); |
| } |
| }); |
| } |