123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185 |
- 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;
- }
- }
|