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PATH: usr / local / lib / node_modules / ghost-cli / node_modules / rxjs / src / internal / operators

import { Operator } from '../Operator';
import { Observable } from '../Observable';
import { Subscriber } from '../Subscriber';
import { Subscription } from '../Subscription';
import { OuterSubscriber } from '../OuterSubscriber';
import { InnerSubscriber } from '../InnerSubscriber';
import { subscribeToResult } from '../util/subscribeToResult';
import { ObservableInput, OperatorFunction, ObservedValueOf } from '../types';
import { map } from './map';
import { from } from '../observable/from';

/* tslint:disable:max-line-length */
export function switchMap<T, O extends ObservableInput<any>>(project: (value: T, index: number) => O): OperatorFunction<T, ObservedValueOf<O>>;
/** @deprecated resultSelector is no longer supported, use inner map instead */
export function switchMap<T, O extends ObservableInput<any>>(project: (value: T, index: number) => O, resultSelector: undefined): OperatorFunction<T, ObservedValueOf<O>>;
/** @deprecated resultSelector is no longer supported, use inner map instead */
export function switchMap<T, R, O extends ObservableInput<any>>(project: (value: T, index: number) => O, resultSelector: (outerValue: T, innerValue: ObservedValueOf<O>, outerIndex: number, innerIndex: number) => R): OperatorFunction<T, R>;
/* tslint:enable:max-line-length */

/**
 * Projects each source value to an Observable which is merged in the output
 * Observable, emitting values only from the most recently projected Observable.
 *
 * <span class="informal">Maps each value to an Observable, then flattens all of
 * these inner Observables.</span>
 *
 * ![](switchMap.png)
 *
 * Returns an Observable that emits items based on applying a function that you
 * supply to each item emitted by the source Observable, where that function
 * returns an (so-called "inner") Observable. Each time it observes one of these
 * inner Observables, the output Observable begins emitting the items emitted by
 * that inner Observable. When a new inner Observable is emitted, `switchMap`
 * stops emitting items from the earlier-emitted inner Observable and begins
 * emitting items from the new one. It continues to behave like this for
 * subsequent inner Observables.
 *
 * ## Example
 * Generate new Observable according to source Observable values
 * ```typescript
 * import { of } from 'rxjs';
 * import { switchMap } from 'rxjs/operators';
 *
 * const switched = of(1, 2, 3).pipe(switchMap((x: number) => of(x, x ** 2, x ** 3)));
 * switched.subscribe(x => console.log(x));
 * // outputs
 * // 1
 * // 1
 * // 1
 * // 2
 * // 4
 * // 8
 * // ... and so on
 * ```
 *
 * Rerun an interval Observable on every click event
 * ```ts
 * import { fromEvent, interval } from 'rxjs';
 * import { switchMap } from 'rxjs/operators';
 *
 * const clicks = fromEvent(document, 'click');
 * const result = clicks.pipe(switchMap((ev) => interval(1000)));
 * result.subscribe(x => console.log(x));
 * ```
 *
 * @see {@link concatMap}
 * @see {@link exhaustMap}
 * @see {@link mergeMap}
 * @see {@link switchAll}
 * @see {@link switchMapTo}
 *
 * @param {function(value: T, ?index: number): ObservableInput} project A function
 * that, when applied to an item emitted by the source Observable, returns an
 * Observable.
 * @return {Observable} An Observable that emits the result of applying the
 * projection function (and the optional deprecated `resultSelector`) to each item
 * emitted by the source Observable and taking only the values from the most recently
 * projected inner Observable.
 * @method switchMap
 * @owner Observable
 */
export function switchMap<T, R, O extends ObservableInput<any>>(
  project: (value: T, index: number) => O,
  resultSelector?: (outerValue: T, innerValue: ObservedValueOf<O>, outerIndex: number, innerIndex: number) => R,
): OperatorFunction<T, ObservedValueOf<O>|R> {
  if (typeof resultSelector === 'function') {
    return (source: Observable<T>) => source.pipe(
      switchMap((a, i) => from(project(a, i)).pipe(
        map((b, ii) => resultSelector(a, b, i, ii))
      ))
    );
  }
  return (source: Observable<T>) => source.lift(new SwitchMapOperator(project));
}

class SwitchMapOperator<T, R> implements Operator<T, R> {
  constructor(private project: (value: T, index: number) => ObservableInput<R>) {
  }

call(subscriber: Subscriber<R>, source: any): any {
    return source.subscribe(new SwitchMapSubscriber(subscriber, this.project));
  }
}

/**
 * We need this JSDoc comment for affecting ESDoc.
 * @ignore
 * @extends {Ignored}
 */
class SwitchMapSubscriber<T, R> extends OuterSubscriber<T, R> {
  private index: number = 0;
  private innerSubscription: Subscription;

constructor(destination: Subscriber<R>,
              private project: (value: T, index: number) => ObservableInput<R>) {
    super(destination);
  }

protected _next(value: T) {
    let result: ObservableInput<R>;
    const index = this.index++;
    try {
      result = this.project(value, index);
    } catch (error) {
      this.destination.error(error);
      return;
    }
    this._innerSub(result, value, index);
  }

private _innerSub(result: ObservableInput<R>, value: T, index: number) {
    const innerSubscription = this.innerSubscription;
    if (innerSubscription) {
      innerSubscription.unsubscribe();
    }
    const innerSubscriber = new InnerSubscriber(this, undefined, undefined);
    const destination = this.destination as Subscription;
    destination.add(innerSubscriber);
    this.innerSubscription = subscribeToResult(this, result, value, index, innerSubscriber);
  }

protected _complete(): void {
    const {innerSubscription} = this;
    if (!innerSubscription || innerSubscription.closed) {
      super._complete();
    }
    this.unsubscribe();
  }

protected _unsubscribe() {
    this.innerSubscription = null;
  }

notifyComplete(innerSub: Subscription): void {
    const destination = this.destination as Subscription;
    destination.remove(innerSub);
    this.innerSubscription = null;
    if (this.isStopped) {
      super._complete();
    }
  }

notifyNext(outerValue: T, innerValue: R,
             outerIndex: number, innerIndex: number,
             innerSub: InnerSubscriber<T, R>): void {
      this.destination.next(innerValue);
  }
}

[-] toArray.ts [edit]
[-] window.ts [edit]
[-] retry.ts [edit]
[-] mergeAll.ts [edit]
[-] windowWhen.ts [edit]
[-] every.ts [edit]
[-] timeout.ts [edit]
[-] debounceTime.ts [edit]
[-] index.ts [edit]
[-] takeWhile.ts [edit]
[-] audit.ts [edit]
[-] reduce.ts [edit]
[-] mapTo.ts [edit]
[-] count.ts [edit]
[-] debounce.ts [edit]
[-] throwIfEmpty.ts [edit]
[-] auditTime.ts [edit]
[-] scan.ts [edit]
[-] switchAll.ts [edit]
[-] map.ts [edit]
[-] bufferCount.ts [edit]
[-] mergeScan.ts [edit]
[-] publish.ts [edit]
[-] min.ts [edit]
[+] ..
[-] publishReplay.ts [edit]
[-] bufferTime.ts [edit]
[-] share.ts [edit]
[-] repeat.ts [edit]
[-] distinct.ts [edit]
[-] concatMapTo.ts [edit]
[-] buffer.ts [edit]
[-] concatMap.ts [edit]
[-] max.ts [edit]
[-] partition.ts [edit]
[-] observeOn.ts [edit]
[-] bufferWhen.ts [edit]
[-] dematerialize.ts [edit]
[-] throttle.ts [edit]
[-] groupBy.ts [edit]
[-] withLatestFrom.ts [edit]
[-] exhaust.ts [edit]
[-] exhaustMap.ts [edit]
[-] retryWhen.ts [edit]
[-] zipAll.ts [edit]
[-] find.ts [edit]
[-] mergeMap.ts [edit]
[-] single.ts [edit]
[-] last.ts [edit]
[-] combineLatest.ts [edit]
[-] publishLast.ts [edit]
[-] pluck.ts [edit]
[-] pairwise.ts [edit]
[-] distinctUntilChanged.ts [edit]
[-] timeInterval.ts [edit]
[-] shareReplay.ts [edit]
[-] skipUntil.ts [edit]
[-] findIndex.ts [edit]
[-] windowToggle.ts [edit]
[-] startWith.ts [edit]
[-] timeoutWith.ts [edit]
[-] concat.ts [edit]
[-] materialize.ts [edit]
[-] timestamp.ts [edit]
[-] onErrorResumeNext.ts [edit]
[-] subscribeOn.ts [edit]
[-] takeUntil.ts [edit]
[-] skipLast.ts [edit]
[-] throttleTime.ts [edit]
[-] mergeMapTo.ts [edit]
[-] multicast.ts [edit]
[-] merge.ts [edit]
[-] takeLast.ts [edit]
[-] delayWhen.ts [edit]
[-] sampleTime.ts [edit]
[-] tap.ts [edit]
[-] take.ts [edit]
[-] sample.ts [edit]
[-] filter.ts [edit]
[-] skip.ts [edit]
[-] expand.ts [edit]
[-] publishBehavior.ts [edit]
[-] sequenceEqual.ts [edit]
[-] ignoreElements.ts [edit]
[-] catchError.ts [edit]
[-] endWith.ts [edit]
[-] refCount.ts [edit]
[-] windowCount.ts [edit]
[-] defaultIfEmpty.ts [edit]
[-] windowTime.ts [edit]
[-] switchMapTo.ts [edit]
[-] switchMap.ts [edit]
[-] delay.ts [edit]
[-] bufferToggle.ts [edit]
[-] repeatWhen.ts [edit]
[-] concatAll.ts [edit]
[-] first.ts [edit]
[-] zip.ts [edit]
[-] elementAt.ts [edit]
[-] skipWhile.ts [edit]
[-] race.ts [edit]
[-] finalize.ts [edit]
[-] combineAll.ts [edit]
[-] distinctUntilKeyChanged.ts [edit]
[-] isEmpty.ts [edit]