+++ /dev/null
-import { Observable } from '../Observable';
-import { Operator } from '../Operator';
-import { Subscriber } from '../Subscriber';
-import { Subscription } from '../Subscription';
-import { Notification } from '../Notification';
-import { MonoTypeOperatorFunction, PartialObserver, SchedulerAction, SchedulerLike, TeardownLogic } from '../types';
-
-/**
- *
- * Re-emits all notifications from source Observable with specified scheduler.
- *
- * <span class="informal">Ensure a specific scheduler is used, from outside of an Observable.</span>
- *
- * `observeOn` is an operator that accepts a scheduler as a first parameter, which will be used to reschedule
- * notifications emitted by the source Observable. It might be useful, if you do not have control over
- * internal scheduler of a given Observable, but want to control when its values are emitted nevertheless.
- *
- * Returned Observable emits the same notifications (nexted values, complete and error events) as the source Observable,
- * but rescheduled with provided scheduler. Note that this doesn't mean that source Observables internal
- * scheduler will be replaced in any way. Original scheduler still will be used, but when the source Observable emits
- * notification, it will be immediately scheduled again - this time with scheduler passed to `observeOn`.
- * An anti-pattern would be calling `observeOn` on Observable that emits lots of values synchronously, to split
- * that emissions into asynchronous chunks. For this to happen, scheduler would have to be passed into the source
- * Observable directly (usually into the operator that creates it). `observeOn` simply delays notifications a
- * little bit more, to ensure that they are emitted at expected moments.
- *
- * As a matter of fact, `observeOn` accepts second parameter, which specifies in milliseconds with what delay notifications
- * will be emitted. The main difference between {@link delay} operator and `observeOn` is that `observeOn`
- * will delay all notifications - including error notifications - while `delay` will pass through error
- * from source Observable immediately when it is emitted. In general it is highly recommended to use `delay` operator
- * for any kind of delaying of values in the stream, while using `observeOn` to specify which scheduler should be used
- * for notification emissions in general.
- *
- * ## Example
- * Ensure values in subscribe are called just before browser repaint.
- * ```ts
- * import { interval } from 'rxjs';
- * import { observeOn } from 'rxjs/operators';
- *
- * const intervals = interval(10); // Intervals are scheduled
- * // with async scheduler by default...
- * intervals.pipe(
- * observeOn(animationFrameScheduler), // ...but we will observe on animationFrame
- * ) // scheduler to ensure smooth animation.
- * .subscribe(val => {
- * someDiv.style.height = val + 'px';
- * });
- * ```
- *
- * @see {@link delay}
- *
- * @param {SchedulerLike} scheduler Scheduler that will be used to reschedule notifications from source Observable.
- * @param {number} [delay] Number of milliseconds that states with what delay every notification should be rescheduled.
- * @return {Observable<T>} Observable that emits the same notifications as the source Observable,
- * but with provided scheduler.
- *
- * @method observeOn
- * @owner Observable
- */
-export function observeOn<T>(scheduler: SchedulerLike, delay: number = 0): MonoTypeOperatorFunction<T> {
- return function observeOnOperatorFunction(source: Observable<T>): Observable<T> {
- return source.lift(new ObserveOnOperator(scheduler, delay));
- };
-}
-
-export class ObserveOnOperator<T> implements Operator<T, T> {
- constructor(private scheduler: SchedulerLike, private delay: number = 0) {
- }
-
- call(subscriber: Subscriber<T>, source: any): TeardownLogic {
- return source.subscribe(new ObserveOnSubscriber(subscriber, this.scheduler, this.delay));
- }
-}
-
-/**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
-export class ObserveOnSubscriber<T> extends Subscriber<T> {
- /** @nocollapse */
- static dispatch(this: SchedulerAction<ObserveOnMessage>, arg: ObserveOnMessage) {
- const { notification, destination } = arg;
- notification.observe(destination);
- this.unsubscribe();
- }
-
- constructor(destination: Subscriber<T>,
- private scheduler: SchedulerLike,
- private delay: number = 0) {
- super(destination);
- }
-
- private scheduleMessage(notification: Notification<any>): void {
- const destination = this.destination as Subscription;
- destination.add(this.scheduler.schedule(
- ObserveOnSubscriber.dispatch,
- this.delay,
- new ObserveOnMessage(notification, this.destination)
- ));
- }
-
- protected _next(value: T): void {
- this.scheduleMessage(Notification.createNext(value));
- }
-
- protected _error(err: any): void {
- this.scheduleMessage(Notification.createError(err));
- this.unsubscribe();
- }
-
- protected _complete(): void {
- this.scheduleMessage(Notification.createComplete());
- this.unsubscribe();
- }
-}
-
-export class ObserveOnMessage {
- constructor(public notification: Notification<any>,
- public destination: PartialObserver<any>) {
- }
-}