61 lines
1.9 KiB
TypeScript
61 lines
1.9 KiB
TypeScript
import { Observable } from '../Observable';
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import { ConnectableObservable } from '../observable/ConnectableObservable';
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import { UnaryFunction } from '../types';
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/**
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* Returns a connectable observable sequence that shares a single subscription to the
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* underlying sequence containing only the last notification.
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*
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* ![](publishLast.png)
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*
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* Similar to {@link publish}, but it waits until the source observable completes and stores
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* the last emitted value.
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* Similarly to {@link publishReplay} and {@link publishBehavior}, this keeps storing the last
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* value even if it has no more subscribers. If subsequent subscriptions happen, they will
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* immediately get that last stored value and complete.
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*
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* ## Example
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*
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* ```ts
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* import { interval } from 'rxjs';
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* import { publishLast, tap, take } from 'rxjs/operators';
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*
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* const connectable =
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* interval(1000)
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* .pipe(
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* tap(x => console.log("side effect", x)),
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* take(3),
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* publishLast());
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*
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* connectable.subscribe(
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* x => console.log( "Sub. A", x),
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* err => console.log("Sub. A Error", err),
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* () => console.log( "Sub. A Complete"));
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*
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* connectable.subscribe(
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* x => console.log( "Sub. B", x),
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* err => console.log("Sub. B Error", err),
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* () => console.log( "Sub. B Complete"));
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*
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* connectable.connect();
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*
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* // Results:
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* // "side effect 0"
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* // "side effect 1"
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* // "side effect 2"
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* // "Sub. A 2"
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* // "Sub. B 2"
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* // "Sub. A Complete"
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* // "Sub. B Complete"
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* ```
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*
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* @see {@link ConnectableObservable}
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* @see {@link publish}
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* @see {@link publishReplay}
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* @see {@link publishBehavior}
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*
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* @return {ConnectableObservable} An observable sequence that contains the elements of a
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* sequence produced by multicasting the source sequence.
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* @method publishLast
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* @owner Observable
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*/
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export declare function publishLast<T>(): UnaryFunction<Observable<T>, ConnectableObservable<T>>;
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