Opal-Estate-Pro/node_modules/rxjs/observable/DeferObservable.d.ts
2019-09-13 11:27:52 +07:00

61 lines
2.7 KiB
TypeScript
Executable File

import { Observable, SubscribableOrPromise } from '../Observable';
import { Subscriber } from '../Subscriber';
import { Subscription } from '../Subscription';
/**
* We need this JSDoc comment for affecting ESDoc.
* @extends {Ignored}
* @hide true
*/
export declare class DeferObservable<T> extends Observable<T> {
private observableFactory;
/**
* Creates an Observable that, on subscribe, calls an Observable factory to
* make an Observable for each new Observer.
*
* <span class="informal">Creates the Observable lazily, that is, only when it
* is subscribed.
* </span>
*
* <img src="./img/defer.png" width="100%">
*
* `defer` allows you to create the Observable only when the Observer
* subscribes, and create a fresh Observable for each Observer. It waits until
* an Observer subscribes to it, and then it generates an Observable,
* typically with an Observable factory function. It does this afresh for each
* subscriber, so although each subscriber may think it is subscribing to the
* same Observable, in fact each subscriber gets its own individual
* Observable.
*
* @example <caption>Subscribe to either an Observable of clicks or an Observable of interval, at random</caption>
* var clicksOrInterval = Rx.Observable.defer(function () {
* if (Math.random() > 0.5) {
* return Rx.Observable.fromEvent(document, 'click');
* } else {
* return Rx.Observable.interval(1000);
* }
* });
* clicksOrInterval.subscribe(x => console.log(x));
*
* // Results in the following behavior:
* // If the result of Math.random() is greater than 0.5 it will listen
* // for clicks anywhere on the "document"; when document is clicked it
* // will log a MouseEvent object to the console. If the result is less
* // than 0.5 it will emit ascending numbers, one every second(1000ms).
*
* @see {@link create}
*
* @param {function(): SubscribableOrPromise} observableFactory The Observable
* factory function to invoke for each Observer that subscribes to the output
* Observable. May also return a Promise, which will be converted on the fly
* to an Observable.
* @return {Observable} An Observable whose Observers' subscriptions trigger
* an invocation of the given Observable factory function.
* @static true
* @name defer
* @owner Observable
*/
static create<T>(observableFactory: () => SubscribableOrPromise<T> | void): Observable<T>;
constructor(observableFactory: () => SubscribableOrPromise<T> | void);
/** @deprecated internal use only */ _subscribe(subscriber: Subscriber<T>): Subscription;
}