[6a3a178] | 1 | import { Observable } from '../Observable';
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| 2 | import { SchedulerLike } from '../types';
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| 3 | /**
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| 4 | * Creates an Observable that emits no items to the Observer and immediately
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| 5 | * emits an error notification.
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| 6 | *
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| 7 | * <span class="informal">Just emits 'error', and nothing else.
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| 8 | * </span>
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| 9 | *
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| 10 | * ![](throw.png)
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| 11 | *
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| 12 | * This static operator is useful for creating a simple Observable that only
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| 13 | * emits the error notification. It can be used for composing with other
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| 14 | * Observables, such as in a {@link mergeMap}.
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| 15 | *
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| 16 | * ## Examples
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| 17 | * ### Emit the number 7, then emit an error
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| 18 | * ```ts
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| 19 | * import { throwError, concat, of } from 'rxjs';
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| 20 | *
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| 21 | * const result = concat(of(7), throwError(new Error('oops!')));
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| 22 | * result.subscribe(x => console.log(x), e => console.error(e));
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| 23 | *
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| 24 | * // Logs:
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| 25 | * // 7
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| 26 | * // Error: oops!
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| 27 | * ```
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| 28 | *
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| 29 | * ---
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| 30 | *
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| 31 | * ### Map and flatten numbers to the sequence 'a', 'b', 'c', but throw an error for 2
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| 32 | * ```ts
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| 33 | * import { throwError, interval, of } from 'rxjs';
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| 34 | * import { mergeMap } from 'rxjs/operators';
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| 35 | *
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| 36 | * interval(1000).pipe(
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| 37 | * mergeMap(x => x === 2
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| 38 | * ? throwError('Twos are bad')
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| 39 | * : of('a', 'b', 'c')
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| 40 | * ),
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| 41 | * ).subscribe(x => console.log(x), e => console.error(e));
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| 42 | *
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| 43 | * // Logs:
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| 44 | * // a
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| 45 | * // b
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| 46 | * // c
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| 47 | * // a
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| 48 | * // b
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| 49 | * // c
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| 50 | * // Twos are bad
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| 51 | * ```
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| 52 | *
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| 53 | * @see {@link Observable}
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| 54 | * @see {@link empty}
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| 55 | * @see {@link never}
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| 56 | * @see {@link of}
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| 57 | *
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| 58 | * @param {any} error The particular Error to pass to the error notification.
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| 59 | * @param {SchedulerLike} [scheduler] A {@link SchedulerLike} to use for scheduling
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| 60 | * the emission of the error notification.
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| 61 | * @return {Observable} An error Observable: emits only the error notification
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| 62 | * using the given error argument.
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| 63 | * @static true
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| 64 | * @name throwError
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| 65 | * @owner Observable
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| 66 | */
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| 67 | export declare function throwError(error: any, scheduler?: SchedulerLike): Observable<never>;
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