48 lines
1.8 KiB
JavaScript
48 lines
1.8 KiB
JavaScript
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"use strict";
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var ArrayObservable_1 = require('../observable/ArrayObservable');
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var ScalarObservable_1 = require('../observable/ScalarObservable');
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var EmptyObservable_1 = require('../observable/EmptyObservable');
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var concat_1 = require('../observable/concat');
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var isScheduler_1 = require('../util/isScheduler');
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/* tslint:enable:max-line-length */
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/**
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* Returns an Observable that emits the items you specify as arguments before it begins to emit
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* items emitted by the source Observable.
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*
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* <img src="./img/startWith.png" width="100%">
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*
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* @param {...T} values - Items you want the modified Observable to emit first.
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* @param {Scheduler} [scheduler] - A {@link IScheduler} to use for scheduling
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* the emissions of the `next` notifications.
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* @return {Observable} An Observable that emits the items in the specified Iterable and then emits the items
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* emitted by the source Observable.
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* @method startWith
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* @owner Observable
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*/
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function startWith() {
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var array = [];
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for (var _i = 0; _i < arguments.length; _i++) {
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array[_i - 0] = arguments[_i];
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}
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return function (source) {
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var scheduler = array[array.length - 1];
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if (isScheduler_1.isScheduler(scheduler)) {
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array.pop();
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}
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else {
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scheduler = null;
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}
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var len = array.length;
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if (len === 1) {
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return concat_1.concat(new ScalarObservable_1.ScalarObservable(array[0], scheduler), source);
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}
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else if (len > 1) {
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return concat_1.concat(new ArrayObservable_1.ArrayObservable(array, scheduler), source);
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}
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else {
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return concat_1.concat(new EmptyObservable_1.EmptyObservable(scheduler), source);
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}
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};
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}
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exports.startWith = startWith;
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//# sourceMappingURL=startWith.js.map
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