--- /dev/null
+import { Operator } from '../Operator';
+import { Subscriber } from '../Subscriber';
+import { Observable } from '../Observable';
+import { Subject } from '../Subject';
+import { Subscription } from '../Subscription';
+
+import { OuterSubscriber } from '../OuterSubscriber';
+import { InnerSubscriber } from '../InnerSubscriber';
+import { subscribeToResult } from '../util/subscribeToResult';
+
+import { MonoTypeOperatorFunction, TeardownLogic } from '../types';
+
+/**
+ * Returns an Observable that mirrors the source Observable with the exception of an `error`. If the source Observable
+ * calls `error`, this method will emit the Throwable that caused the error to the Observable returned from `notifier`.
+ * If that Observable calls `complete` or `error` then this method will call `complete` or `error` on the child
+ * subscription. Otherwise this method will resubscribe to the source Observable.
+ *
+ * ![](retryWhen.png)
+ *
+ * @param {function(errors: Observable): Observable} notifier - Receives an Observable of notifications with which a
+ * user can `complete` or `error`, aborting the retry.
+ * @return {Observable} The source Observable modified with retry logic.
+ * @method retryWhen
+ * @owner Observable
+ */
+export function retryWhen<T>(notifier: (errors: Observable<any>) => Observable<any>): MonoTypeOperatorFunction<T> {
+ return (source: Observable<T>) => source.lift(new RetryWhenOperator(notifier, source));
+}
+
+class RetryWhenOperator<T> implements Operator<T, T> {
+ constructor(protected notifier: (errors: Observable<any>) => Observable<any>,
+ protected source: Observable<T>) {
+ }
+
+ call(subscriber: Subscriber<T>, source: any): TeardownLogic {
+ return source.subscribe(new RetryWhenSubscriber(subscriber, this.notifier, this.source));
+ }
+}
+
+/**
+ * We need this JSDoc comment for affecting ESDoc.
+ * @ignore
+ * @extends {Ignored}
+ */
+class RetryWhenSubscriber<T, R> extends OuterSubscriber<T, R> {
+
+ private errors: Subject<any>;
+ private retries: Observable<any>;
+ private retriesSubscription: Subscription;
+
+ constructor(destination: Subscriber<R>,
+ private notifier: (errors: Observable<any>) => Observable<any>,
+ private source: Observable<T>) {
+ super(destination);
+ }
+
+ error(err: any) {
+ if (!this.isStopped) {
+
+ let errors = this.errors;
+ let retries: any = this.retries;
+ let retriesSubscription = this.retriesSubscription;
+
+ if (!retries) {
+ errors = new Subject();
+ try {
+ const { notifier } = this;
+ retries = notifier(errors);
+ } catch (e) {
+ return super.error(e);
+ }
+ retriesSubscription = subscribeToResult(this, retries);
+ } else {
+ this.errors = null;
+ this.retriesSubscription = null;
+ }
+
+ this._unsubscribeAndRecycle();
+
+ this.errors = errors;
+ this.retries = retries;
+ this.retriesSubscription = retriesSubscription;
+
+ errors.next(err);
+ }
+ }
+
+ /** @deprecated This is an internal implementation detail, do not use. */
+ _unsubscribe() {
+ const { errors, retriesSubscription } = this;
+ if (errors) {
+ errors.unsubscribe();
+ this.errors = null;
+ }
+ if (retriesSubscription) {
+ retriesSubscription.unsubscribe();
+ this.retriesSubscription = null;
+ }
+ this.retries = null;
+ }
+
+ notifyNext(outerValue: T, innerValue: R,
+ outerIndex: number, innerIndex: number,
+ innerSub: InnerSubscriber<T, R>): void {
+ const { _unsubscribe } = this;
+
+ this._unsubscribe = null;
+ this._unsubscribeAndRecycle();
+ this._unsubscribe = _unsubscribe;
+
+ this.source.subscribe(this);
+ }
+}