46 lines
1.9 KiB
JavaScript
46 lines
1.9 KiB
JavaScript
"use strict";
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var __extends = (this && this.__extends) || function (d, b) {
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for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
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function __() { this.constructor = d; }
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d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
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};
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var Subscriber_1 = require('../Subscriber');
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/**
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* Returns an Observable that emits the elements of the source or a specified default value if empty.
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* @param {any} defaultValue the default value used if source is empty; defaults to null.
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* @returns {Observable} an Observable of the items emitted by the where empty values are replaced by the specified default value or null.
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*/
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function defaultIfEmpty(defaultValue) {
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if (defaultValue === void 0) { defaultValue = null; }
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return this.lift(new DefaultIfEmptyOperator(defaultValue));
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}
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exports.defaultIfEmpty = defaultIfEmpty;
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var DefaultIfEmptyOperator = (function () {
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function DefaultIfEmptyOperator(defaultValue) {
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this.defaultValue = defaultValue;
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}
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DefaultIfEmptyOperator.prototype.call = function (subscriber) {
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return new DefaultIfEmptySubscriber(subscriber, this.defaultValue);
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};
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return DefaultIfEmptyOperator;
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}());
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var DefaultIfEmptySubscriber = (function (_super) {
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__extends(DefaultIfEmptySubscriber, _super);
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function DefaultIfEmptySubscriber(destination, defaultValue) {
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_super.call(this, destination);
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this.defaultValue = defaultValue;
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this.isEmpty = true;
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}
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DefaultIfEmptySubscriber.prototype._next = function (value) {
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this.isEmpty = false;
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this.destination.next(value);
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};
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DefaultIfEmptySubscriber.prototype._complete = function () {
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if (this.isEmpty) {
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this.destination.next(this.defaultValue);
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}
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this.destination.complete();
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};
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return DefaultIfEmptySubscriber;
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}(Subscriber_1.Subscriber));
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//# sourceMappingURL=defaultIfEmpty.js.map
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