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Diffstat (limited to 'node_modules/rxjs/src/internal/Subject.ts')
| -rw-r--r-- | node_modules/rxjs/src/internal/Subject.ts | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/node_modules/rxjs/src/internal/Subject.ts b/node_modules/rxjs/src/internal/Subject.ts new file mode 100644 index 0000000..61ed267 --- /dev/null +++ b/node_modules/rxjs/src/internal/Subject.ts @@ -0,0 +1,185 @@ +import { Operator } from './Operator'; +import { Observable } from './Observable'; +import { Subscriber } from './Subscriber'; +import { Subscription, EMPTY_SUBSCRIPTION } from './Subscription'; +import { Observer, SubscriptionLike, TeardownLogic } from './types'; +import { ObjectUnsubscribedError } from './util/ObjectUnsubscribedError'; +import { arrRemove } from './util/arrRemove'; +import { errorContext } from './util/errorContext'; + +/** + * A Subject is a special type of Observable that allows values to be + * multicasted to many Observers. Subjects are like EventEmitters. + * + * Every Subject is an Observable and an Observer. You can subscribe to a + * Subject, and you can call next to feed values as well as error and complete. + */ +export class Subject<T> extends Observable<T> implements SubscriptionLike { + closed = false; + + private currentObservers: Observer<T>[] | null = null; + + /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */ + observers: Observer<T>[] = []; + /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */ + isStopped = false; + /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */ + hasError = false; + /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */ + thrownError: any = null; + + /** + * Creates a "subject" by basically gluing an observer to an observable. + * + * @deprecated Recommended you do not use. Will be removed at some point in the future. Plans for replacement still under discussion. + */ + static create: (...args: any[]) => any = <T>(destination: Observer<T>, source: Observable<T>): AnonymousSubject<T> => { + return new AnonymousSubject<T>(destination, source); + }; + + constructor() { + // NOTE: This must be here to obscure Observable's constructor. + super(); + } + + /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */ + lift<R>(operator: Operator<T, R>): Observable<R> { + const subject = new AnonymousSubject(this, this); + subject.operator = operator as any; + return subject as any; + } + + /** @internal */ + protected _throwIfClosed() { + if (this.closed) { + throw new ObjectUnsubscribedError(); + } + } + + next(value: T) { + errorContext(() => { + this._throwIfClosed(); + if (!this.isStopped) { + if (!this.currentObservers) { + this.currentObservers = Array.from(this.observers); + } + for (const observer of this.currentObservers) { + observer.next(value); + } + } + }); + } + + error(err: any) { + errorContext(() => { + this._throwIfClosed(); + if (!this.isStopped) { + this.hasError = this.isStopped = true; + this.thrownError = err; + const { observers } = this; + while (observers.length) { + observers.shift()!.error(err); + } + } + }); + } + + complete() { + errorContext(() => { + this._throwIfClosed(); + if (!this.isStopped) { + this.isStopped = true; + const { observers } = this; + while (observers.length) { + observers.shift()!.complete(); + } + } + }); + } + + unsubscribe() { + this.isStopped = this.closed = true; + this.observers = this.currentObservers = null!; + } + + get observed() { + return this.observers?.length > 0; + } + + /** @internal */ + protected _trySubscribe(subscriber: Subscriber<T>): TeardownLogic { + this._throwIfClosed(); + return super._trySubscribe(subscriber); + } + + /** @internal */ + protected _subscribe(subscriber: Subscriber<T>): Subscription { + this._throwIfClosed(); + this._checkFinalizedStatuses(subscriber); + return this._innerSubscribe(subscriber); + } + + /** @internal */ + protected _innerSubscribe(subscriber: Subscriber<any>) { + const { hasError, isStopped, observers } = this; + if (hasError || isStopped) { + return EMPTY_SUBSCRIPTION; + } + this.currentObservers = null; + observers.push(subscriber); + return new Subscription(() => { + this.currentObservers = null; + arrRemove(observers, subscriber); + }); + } + + /** @internal */ + protected _checkFinalizedStatuses(subscriber: Subscriber<any>) { + const { hasError, thrownError, isStopped } = this; + if (hasError) { + subscriber.error(thrownError); + } else if (isStopped) { + subscriber.complete(); + } + } + + /** + * Creates a new Observable with this Subject as the source. You can do this + * to create custom Observer-side logic of the Subject and conceal it from + * code that uses the Observable. + * @return Observable that this Subject casts to. + */ + asObservable(): Observable<T> { + const observable: any = new Observable<T>(); + observable.source = this; + return observable; + } +} + +export class AnonymousSubject<T> extends Subject<T> { + constructor( + /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */ + public destination?: Observer<T>, + source?: Observable<T> + ) { + super(); + this.source = source; + } + + next(value: T) { + this.destination?.next?.(value); + } + + error(err: any) { + this.destination?.error?.(err); + } + + complete() { + this.destination?.complete?.(); + } + + /** @internal */ + protected _subscribe(subscriber: Subscriber<T>): Subscription { + return this.source?.subscribe(subscriber) ?? EMPTY_SUBSCRIPTION; + } +} |
