| /** PURE_IMPORTS_START .._Observable,.._util_subscribeToResult,.._OuterSubscriber PURE_IMPORTS_END */ |
| var __extends = (this && this.__extends) || function (d, b) { |
| for (var p in b) |
| if (b.hasOwnProperty(p)) |
| d[p] = b[p]; |
| function __() { this.constructor = d; } |
| d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __()); |
| }; |
| import { Observable } from '../Observable'; |
| import { subscribeToResult } from '../util/subscribeToResult'; |
| import { OuterSubscriber } from '../OuterSubscriber'; |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @extends {Ignored} |
| * @hide true |
| */ |
| export var DeferObservable = /*@__PURE__*/ (/*@__PURE__*/ function (_super) { |
| __extends(DeferObservable, _super); |
| function DeferObservable(observableFactory) { |
| _super.call(this); |
| this.observableFactory = 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 |
| */ |
| DeferObservable.create = function (observableFactory) { |
| return new DeferObservable(observableFactory); |
| }; |
| DeferObservable.prototype._subscribe = function (subscriber) { |
| return new DeferSubscriber(subscriber, this.observableFactory); |
| }; |
| return DeferObservable; |
| }(Observable)); |
| var DeferSubscriber = /*@__PURE__*/ (/*@__PURE__*/ function (_super) { |
| __extends(DeferSubscriber, _super); |
| function DeferSubscriber(destination, factory) { |
| _super.call(this, destination); |
| this.factory = factory; |
| this.tryDefer(); |
| } |
| DeferSubscriber.prototype.tryDefer = function () { |
| try { |
| this._callFactory(); |
| } |
| catch (err) { |
| this._error(err); |
| } |
| }; |
| DeferSubscriber.prototype._callFactory = function () { |
| var result = this.factory(); |
| if (result) { |
| this.add(subscribeToResult(this, result)); |
| } |
| }; |
| return DeferSubscriber; |
| }(OuterSubscriber)); |
| //# sourceMappingURL=DeferObservable.js.map |