25 lines
698 B
TypeScript
25 lines
698 B
TypeScript
import { combineLatest, Observable } from "rxjs"
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import { map } from "rxjs/operators"
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/**
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* Constructs a stream of a object from a collection of other observables
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*
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* @param streamObj The object containing key of observables to assemble from
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*
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* @returns The constructed object observable
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*/
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export function constructFromStreams<T>(streamObj: {
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[key in keyof T]: Observable<T[key]>
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}): Observable<T> {
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return combineLatest(Object.values<Observable<T[keyof T]>>(streamObj)).pipe(
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map((streams) => {
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const keys = Object.keys(streamObj) as (keyof T)[]
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return keys.reduce(
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(acc, s, i) => Object.assign(acc, { [s]: streams[i] }),
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{}
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) as T
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})
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)
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}
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