@reactivex/rxjs
Version:
Reactive Extensions for modern JavaScript
63 lines • 2.6 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
var SubscribeOnObservable_1 = require("../observable/SubscribeOnObservable");
/**
* Asynchronously subscribes Observers to this Observable on the specified {@link SchedulerLike}.
*
* With `subscribeOn` you can decide what type of scheduler a specific Observable will be using when it is subscribed to.
*
* Schedulers control the speed and order of emissions to observers from an Observable stream.
*
* 
*
* ## Example
* Given the following code:
* ```javascript
* import { of, merge } from 'rxjs';
*
* const a = of(1, 2, 3, 4);
* const b = of(5, 6, 7, 8, 9);
* merge(a, b).subscribe(console.log);
* ```
*
* Both Observable `a` and `b` will emit their values directly and synchronously once they are subscribed to.
* This will result in the output of `1 2 3 4 5 6 7 8 9`.
*
* But if we instead us the `subscribeOn` operator declaring that we want to use the {@link asyncScheduler} for values emited by Observable `a`:
* ```javascript
* import { of, merge, asyncScheduler } from 'rxjs';
* import { subscribeOn } from 'rxjs/operators';
*
* const a = of(1, 2, 3, 4).pipe(subscribeOn(asyncScheduler));
* const b = of(5, 6, 7, 8, 9);
* merge(a, b).subscribe(console.log);
* ```
*
* The output will instead be `5 6 7 8 9 1 2 3 4`.
* The reason for this is that Observable `b` emits its values directly and synchronously like before
* but the emissions from `a` are scheduled on the event loop because we are now using the {@link asyncScheduler} for that specific Observable.
*
* @param {SchedulerLike} scheduler - The {@link SchedulerLike} to perform subscription actions on.
* @return {Observable<T>} The source Observable modified so that its subscriptions happen on the specified {@link SchedulerLike}.
.
* @method subscribeOn
* @owner Observable
*/
function subscribeOn(scheduler, delay) {
if (delay === void 0) { delay = 0; }
return function subscribeOnOperatorFunction(source) {
return source.lift(new SubscribeOnOperator(scheduler, delay));
};
}
exports.subscribeOn = subscribeOn;
var SubscribeOnOperator = /** @class */ (function () {
function SubscribeOnOperator(scheduler, delay) {
this.scheduler = scheduler;
this.delay = delay;
}
SubscribeOnOperator.prototype.call = function (subscriber, source) {
return new SubscribeOnObservable_1.SubscribeOnObservable(source, this.delay, this.scheduler).subscribe(subscriber);
};
return SubscribeOnOperator;
}());
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