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- "use strict";
- 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 __());
- };
- var Subscriber_1 = require('../Subscriber');
- /* tslint:enable:max-line-length */
- /**
- * Emits a given value if the source Observable completes without emitting any
- * `next` value, otherwise mirrors the source Observable.
- *
- * <span class="informal">If the source Observable turns out to be empty, then
- * this operator will emit a default value.</span>
- *
- * <img src="./img/defaultIfEmpty.png" width="100%">
- *
- * `defaultIfEmpty` emits the values emitted by the source Observable or a
- * specified default value if the source Observable is empty (completes without
- * having emitted any `next` value).
- *
- * @example <caption>If no clicks happen in 5 seconds, then emit "no clicks"</caption>
- * var clicks = Rx.Observable.fromEvent(document, 'click');
- * var clicksBeforeFive = clicks.takeUntil(Rx.Observable.interval(5000));
- * var result = clicksBeforeFive.defaultIfEmpty('no clicks');
- * result.subscribe(x => console.log(x));
- *
- * @see {@link empty}
- * @see {@link last}
- *
- * @param {any} [defaultValue=null] The default value used if the source
- * Observable is empty.
- * @return {Observable} An Observable that emits either the specified
- * `defaultValue` if the source Observable emits no items, or the values emitted
- * by the source Observable.
- * @method defaultIfEmpty
- * @owner Observable
- */
- function defaultIfEmpty(defaultValue) {
- if (defaultValue === void 0) { defaultValue = null; }
- return function (source) { return source.lift(new DefaultIfEmptyOperator(defaultValue)); };
- }
- exports.defaultIfEmpty = defaultIfEmpty;
- var DefaultIfEmptyOperator = (function () {
- function DefaultIfEmptyOperator(defaultValue) {
- this.defaultValue = defaultValue;
- }
- DefaultIfEmptyOperator.prototype.call = function (subscriber, source) {
- return source.subscribe(new DefaultIfEmptySubscriber(subscriber, this.defaultValue));
- };
- return DefaultIfEmptyOperator;
- }());
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- var DefaultIfEmptySubscriber = (function (_super) {
- __extends(DefaultIfEmptySubscriber, _super);
- function DefaultIfEmptySubscriber(destination, defaultValue) {
- _super.call(this, destination);
- this.defaultValue = defaultValue;
- this.isEmpty = true;
- }
- DefaultIfEmptySubscriber.prototype._next = function (value) {
- this.isEmpty = false;
- this.destination.next(value);
- };
- DefaultIfEmptySubscriber.prototype._complete = function () {
- if (this.isEmpty) {
- this.destination.next(this.defaultValue);
- }
- this.destination.complete();
- };
- return DefaultIfEmptySubscriber;
- }(Subscriber_1.Subscriber));
- //# sourceMappingURL=defaultIfEmpty.js.map
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