rxjs
Version:
Reactive Extensions for modern JavaScript
65 lines • 2.09 kB
JavaScript
import { Observable } from '../Observable';
import { isArray } from '../util/isArray';
import { EMPTY } from './empty';
import { subscribeToResult } from '../util/subscribeToResult';
import { OuterSubscriber } from '../OuterSubscriber';
import { map } from '../operators/map';
export function forkJoin(...sources) {
let resultSelector;
if (typeof sources[sources.length - 1] === 'function') {
resultSelector = sources.pop();
}
if (sources.length === 1 && isArray(sources[0])) {
sources = sources[0];
}
if (sources.length === 0) {
return EMPTY;
}
if (resultSelector) {
return forkJoin(sources).pipe(map(args => resultSelector(...args)));
}
return new Observable(subscriber => {
return new ForkJoinSubscriber(subscriber, sources);
});
}
class ForkJoinSubscriber extends OuterSubscriber {
constructor(destination, sources) {
super(destination);
this.sources = sources;
this.completed = 0;
this.haveValues = 0;
const len = sources.length;
this.values = new Array(len);
for (let i = 0; i < len; i++) {
const source = sources[i];
const innerSubscription = subscribeToResult(this, source, null, i);
if (innerSubscription) {
this.add(innerSubscription);
}
}
}
notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) {
this.values[outerIndex] = innerValue;
if (!innerSub._hasValue) {
innerSub._hasValue = true;
this.haveValues++;
}
}
notifyComplete(innerSub) {
const { destination, haveValues, values } = this;
const len = values.length;
if (!innerSub._hasValue) {
destination.complete();
return;
}
this.completed++;
if (this.completed !== len) {
return;
}
if (haveValues === len) {
destination.next(values);
}
destination.complete();
}
}
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