import {root} from '../util/root';
import {Scheduler} from '../Scheduler';
import {Observable} from '../Observable';
import {Subscriber} from '../Subscriber';
import {Subscription} from '../Subscription';
export class PromiseObservable<T> extends Observable<T> {
public value: T;
static create<T>(promise: Promise<T>, Escheduler: Scheduler = null): Observable<T> {
return new PromiseObservable(promise, scheduler);
}
constructor(private promise: Promise<T>, public scheduler: Scheduler = null) {
super();
}
protected _subscribe(subscriber: Subscriber<T>): Subscription | Function | void {
const promise = this.promise;
const scheduler = this.scheduler;
Eif (scheduler == null) {
if (this._isScalar) {
Eif (!subscriber.isUnsubscribed) {
subscriber.next(this.value);
subscriber.complete();
}
} else {
promise.then(
(value) => {
this.value = value;
this._isScalar = true;
if (!subscriber.isUnsubscribed) {
subscriber.next(value);
subscriber.complete();
}
},
(err) => {
if (!subscriber.isUnsubscribed) {
subscriber.error(err);
}
}
)
.then(null, err => {
// escape the promise trap, throw unhandled errors
root.setTimeout(() => { throw err; });
});
}
} else {
if (this._isScalar) {
if (!subscriber.isUnsubscribed) {
return scheduler.schedule(dispatchNext, 0, { value: this.value, subscriber });
}
} else {
promise.then(
(value) => {
this.value = value;
this._isScalar = true;
if (!subscriber.isUnsubscribed) {
subscriber.add(scheduler.schedule(dispatchNext, 0, { value, subscriber }));
}
},
(err) => {
if (!subscriber.isUnsubscribed) {
subscriber.add(scheduler.schedule(dispatchError, 0, { err, subscriber }));
}
})
.then(null, (err) => {
// escape the promise trap, throw unhandled errors
root.setTimeout(() => { throw err; });
});
}
}
}
}
function dispatchNext({ value, subscriber }) {
if (!subscriber.isUnsubscribed) {
subscriber.next(value);
subscriber.complete();
}
}
function dispatchError({ err, subscriber }) {
if (!subscriber.isUnsubscribed) {
subscriber.error(err);
}
}
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