1 import { Observable } from '../Observable';
2 import { from } from '../observable/from';
3 import { Operator } from '../Operator';
4 import { Subscriber } from '../Subscriber';
5 import { Subscription } from '../Subscription';
6 import { isArray } from '../util/isArray';
7 import { OuterSubscriber } from '../OuterSubscriber';
8 import { InnerSubscriber } from '../InnerSubscriber';
9 import { subscribeToResult } from '../util/subscribeToResult';
10 import { ObservableInput, OperatorFunction } from '../types';
12 /* tslint:disable:max-line-length */
13 export function onErrorResumeNext<T>(): OperatorFunction<T, T>;
14 export function onErrorResumeNext<T, T2>(v: ObservableInput<T2>): OperatorFunction<T, T | T2>;
15 export function onErrorResumeNext<T, T2, T3>(v: ObservableInput<T2>, v2: ObservableInput<T3>): OperatorFunction<T, T | T2 | T3>;
16 export function onErrorResumeNext<T, T2, T3, T4>(v: ObservableInput<T2>, v2: ObservableInput<T3>, v3: ObservableInput<T4>): OperatorFunction<T, T | T2 | T3 | T4>;
17 export function onErrorResumeNext<T, T2, T3, T4, T5>(v: ObservableInput<T2>, v2: ObservableInput<T3>, v3: ObservableInput<T4>, v4: ObservableInput<T5>): OperatorFunction<T, T | T2 | T3 | T4 | T5>;
18 export function onErrorResumeNext<T, T2, T3, T4, T5, T6>(v: ObservableInput<T2>, v2: ObservableInput<T3>, v3: ObservableInput<T4>, v4: ObservableInput<T5>, v5: ObservableInput<T6>): OperatorFunction<T, T | T2 | T3 | T4 | T5 | T6>;
19 export function onErrorResumeNext<T, T2, T3, T4, T5, T6, T7>(v: ObservableInput<T2>, v2: ObservableInput<T3>, v3: ObservableInput<T4>, v4: ObservableInput<T5>, v5: ObservableInput<T6>, v6: ObservableInput<T7>): OperatorFunction<T, T | T2 | T3 | T4 | T5 | T6 | T7>;
20 export function onErrorResumeNext<T, R>(...observables: Array<ObservableInput<any>>): OperatorFunction<T, T | R>;
21 export function onErrorResumeNext<T, R>(array: ObservableInput<any>[]): OperatorFunction<T, T | R>;
22 /* tslint:enable:max-line-length */
25 * When any of the provided Observable emits an complete or error notification, it immediately subscribes to the next one
28 * <span class="informal">Execute series of Observables no matter what, even if it means swallowing errors.</span>
30 * ![](onErrorResumeNext.png)
32 * `onErrorResumeNext` is an operator that accepts a series of Observables, provided either directly as
33 * arguments or as an array. If no single Observable is provided, returned Observable will simply behave the same
36 * `onErrorResumeNext` returns an Observable that starts by subscribing and re-emitting values from the source Observable.
37 * When its stream of values ends - no matter if Observable completed or emitted an error - `onErrorResumeNext`
38 * will subscribe to the first Observable that was passed as an argument to the method. It will start re-emitting
39 * its values as well and - again - when that stream ends, `onErrorResumeNext` will proceed to subscribing yet another
40 * Observable in provided series, no matter if previous Observable completed or ended with an error. This will
41 * be happening until there is no more Observables left in the series, at which point returned Observable will
42 * complete - even if the last subscribed stream ended with an error.
44 * `onErrorResumeNext` can be therefore thought of as version of {@link concat} operator, which is more permissive
45 * when it comes to the errors emitted by its input Observables. While `concat` subscribes to the next Observable
46 * in series only if previous one successfully completed, `onErrorResumeNext` subscribes even if it ended with
49 * Note that you do not get any access to errors emitted by the Observables. In particular do not
50 * expect these errors to appear in error callback passed to {@link Observable#subscribe}. If you want to take
51 * specific actions based on what error was emitted by an Observable, you should try out {@link catchError} instead.
55 * Subscribe to the next Observable after map fails
57 * import { of } from 'rxjs';
58 * import { onErrorResumeNext, map } from 'rxjs/operators';
60 * of(1, 2, 3, 0).pipe(
62 * if (x === 0) { throw Error(); }
65 * onErrorResumeNext(of(1, 2, 3)),
68 * val => console.log(val),
69 * err => console.log(err), // Will never be called.
70 * () => console.log('that\'s it!')
76 * // 3.3333333333333335
84 * @see {@link catchError}
86 * @param {...ObservableInput} observables Observables passed either directly or as an array.
87 * @return {Observable} An Observable that emits values from source Observable, but - if it errors - subscribes
88 * to the next passed Observable and so on, until it completes or runs out of Observables.
89 * @method onErrorResumeNext
93 export function onErrorResumeNext<T, R>(...nextSources: Array<ObservableInput<any> |
94 Array<ObservableInput<any>>>): OperatorFunction<T, R> {
95 if (nextSources.length === 1 && isArray(nextSources[0])) {
96 nextSources = <Array<Observable<any>>>nextSources[0];
99 return (source: Observable<T>) => source.lift(new OnErrorResumeNextOperator<T, R>(nextSources));
102 /* tslint:disable:max-line-length */
103 export function onErrorResumeNextStatic<R>(v: ObservableInput<R>): Observable<R>;
104 export function onErrorResumeNextStatic<T2, T3, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>): Observable<R>;
105 export function onErrorResumeNextStatic<T2, T3, T4, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>): Observable<R>;
106 export function onErrorResumeNextStatic<T2, T3, T4, T5, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>): Observable<R>;
107 export function onErrorResumeNextStatic<T2, T3, T4, T5, T6, R>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>): Observable<R>;
109 export function onErrorResumeNextStatic<R>(...observables: Array<ObservableInput<any> | ((...values: Array<any>) => R)>): Observable<R>;
110 export function onErrorResumeNextStatic<R>(array: ObservableInput<any>[]): Observable<R>;
111 /* tslint:enable:max-line-length */
113 export function onErrorResumeNextStatic<T, R>(...nextSources: Array<ObservableInput<any> |
114 Array<ObservableInput<any>> |
115 ((...values: Array<any>) => R)>): Observable<R> {
116 let source: ObservableInput<any> = null;
118 if (nextSources.length === 1 && isArray(nextSources[0])) {
119 nextSources = <Array<ObservableInput<any>>>nextSources[0];
121 source = nextSources.shift();
123 return from(source, null).lift(new OnErrorResumeNextOperator<T, R>(nextSources));
126 class OnErrorResumeNextOperator<T, R> implements Operator<T, R> {
127 constructor(private nextSources: Array<ObservableInput<any>>) {
130 call(subscriber: Subscriber<R>, source: any): any {
131 return source.subscribe(new OnErrorResumeNextSubscriber(subscriber, this.nextSources));
135 class OnErrorResumeNextSubscriber<T, R> extends OuterSubscriber<T, R> {
136 constructor(protected destination: Subscriber<T>,
137 private nextSources: Array<ObservableInput<any>>) {
141 notifyError(error: any, innerSub: InnerSubscriber<T, any>): void {
142 this.subscribeToNextSource();
145 notifyComplete(innerSub: InnerSubscriber<T, any>): void {
146 this.subscribeToNextSource();
149 protected _error(err: any): void {
150 this.subscribeToNextSource();
154 protected _complete(): void {
155 this.subscribeToNextSource();
159 private subscribeToNextSource(): void {
160 const next = this.nextSources.shift();
162 const innerSubscriber = new InnerSubscriber(this, undefined, undefined);
163 const destination = this.destination as Subscription;
164 destination.add(innerSubscriber);
165 const innerSubscription = subscribeToResult(this, next, undefined, undefined, innerSubscriber);
166 // The returned subscription will usually be the subscriber that was
167 // passed. However, interop subscribers will be wrapped and for
168 // unsubscriptions to chain correctly, the wrapper needs to be added, too.
169 if (innerSubscription !== innerSubscriber) {
170 destination.add(innerSubscription);
173 this.destination.complete();