@acutmore/rxjs/dist/typings/internal/observable/UsingObservable.d.ts

Reactive Extensions for modern JavaScript

import { Observable, SubscribableOrPromise } from '../Observable';
import { Subscriber } from '../Subscriber';
import { AnonymousSubscription, TeardownLogic } from '../Subscription';
/**
 * We need this JSDoc comment for affecting ESDoc.
 * @extends {Ignored}
 * @hide true
 */
export declare class UsingObservable<T> extends Observable<T> {
    private resourceFactory;
    private observableFactory;
    /**
     * Creates an Observable that uses a resource which will be disposed at the same time as the Observable.
     *
     * <span class="informal">Use it when you catch yourself cleaning up after an Observable.</span>
     *
     * `using` is a factory operator, which accepts two functions. First function returns a disposable resource.
     * It can be an arbitrary object that implements `unsubscribe` method. Second function will be injected with
     * that object and should return an Observable. That Observable can use resource object during its execution.
     * Both functions passed to `using` will be called every time someone subscribes - neither an Observable nor
     * resource object will be shared in any way between subscriptions.
     *
     * When Observable returned by `using` is subscribed, Observable returned from the second function will be subscribed
     * as well. All its notifications (nexted values, completion and error events) will be emitted unchanged by the output
     * Observable. If however someone unsubscribes from the Observable or source Observable completes or errors by itself,
     * the `unsubscribe` method on resource object will be called. This can be used to do any necessary clean up, which
     * otherwise would have to be handled by hand. Note that complete or error notifications are not emitted when someone
     * cancels subscription to an Observable via `unsubscribe`, so `using` can be used as a hook, allowing you to make
     * sure that all resources which need to exist during an Observable execution will be disposed at appropriate time.
     *
     * @see {@link defer}
     *
     * @param {function(): ISubscription} resourceFactory A function which creates any resource object
     * that implements `unsubscribe` method.
     * @param {function(resource: ISubscription): Observable<T>} observableFactory A function which
     * creates an Observable, that can use injected resource object.
     * @return {Observable<T>} An Observable that behaves the same as Observable returned by `observableFactory`, but
     * which - when completed, errored or unsubscribed - will also call `unsubscribe` on created resource object.
     * @static true
     * @name using
     * @owner Observable
     */
    static create<T>(resourceFactory: () => AnonymousSubscription | void, observableFactory: (resource: AnonymousSubscription) => SubscribableOrPromise<T> | void): Observable<T>;
    constructor(resourceFactory: () => AnonymousSubscription | void, observableFactory: (resource: AnonymousSubscription) => SubscribableOrPromise<T> | void);
    protected _subscribe(subscriber: Subscriber<T>): TeardownLogic;
}