Opal-Estate-Pro/node_modules/rxjs/_esm2015/operators/multicast.js

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2019-09-13 06:27:52 +02:00
import { connectableObservableDescriptor } from '../observable/ConnectableObservable';
/* tslint:enable:max-line-length */
/**
* Returns an Observable that emits the results of invoking a specified selector on items
* emitted by a ConnectableObservable that shares a single subscription to the underlying stream.
*
* <img src="./img/multicast.png" width="100%">
*
* @param {Function|Subject} subjectOrSubjectFactory - Factory function to create an intermediate subject through
* which the source sequence's elements will be multicast to the selector function
* or Subject to push source elements into.
* @param {Function} [selector] - Optional selector function that can use the multicasted source stream
* as many times as needed, without causing multiple subscriptions to the source stream.
* Subscribers to the given source will receive all notifications of the source from the
* time of the subscription forward.
* @return {Observable} An Observable that emits the results of invoking the selector
* on the items emitted by a `ConnectableObservable` that shares a single subscription to
* the underlying stream.
* @method multicast
* @owner Observable
*/
export function multicast(subjectOrSubjectFactory, selector) {
return function multicastOperatorFunction(source) {
let subjectFactory;
if (typeof subjectOrSubjectFactory === 'function') {
subjectFactory = subjectOrSubjectFactory;
}
else {
subjectFactory = function subjectFactory() {
return subjectOrSubjectFactory;
};
}
if (typeof selector === 'function') {
return source.lift(new MulticastOperator(subjectFactory, selector));
}
const connectable = Object.create(source, connectableObservableDescriptor);
connectable.source = source;
connectable.subjectFactory = subjectFactory;
return connectable;
};
}
export class MulticastOperator {
constructor(subjectFactory, selector) {
this.subjectFactory = subjectFactory;
this.selector = selector;
}
call(subscriber, source) {
const { selector } = this;
const subject = this.subjectFactory();
const subscription = selector(subject).subscribe(subscriber);
subscription.add(source.subscribe(subject));
return subscription;
}
}
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