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39 lines
1.6 KiB
39 lines
1.6 KiB
"use strict"; |
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var defaultIfEmpty_1 = require('../operators/defaultIfEmpty'); |
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/* tslint:enable:max-line-length */ |
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/** |
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* Emits a given value if the source Observable completes without emitting any |
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* `next` value, otherwise mirrors the source Observable. |
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* |
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* <span class="informal">If the source Observable turns out to be empty, then |
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* this operator will emit a default value.</span> |
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* |
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* <img src="./img/defaultIfEmpty.png" width="100%"> |
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* |
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* `defaultIfEmpty` emits the values emitted by the source Observable or a |
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* specified default value if the source Observable is empty (completes without |
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* having emitted any `next` value). |
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* |
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* @example <caption>If no clicks happen in 5 seconds, then emit "no clicks"</caption> |
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* var clicks = Rx.Observable.fromEvent(document, 'click'); |
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* var clicksBeforeFive = clicks.takeUntil(Rx.Observable.interval(5000)); |
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* var result = clicksBeforeFive.defaultIfEmpty('no clicks'); |
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* result.subscribe(x => console.log(x)); |
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* |
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* @see {@link empty} |
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* @see {@link last} |
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* |
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* @param {any} [defaultValue=null] The default value used if the source |
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* Observable is empty. |
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* @return {Observable} An Observable that emits either the specified |
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* `defaultValue` if the source Observable emits no items, or the values emitted |
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* by the source Observable. |
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* @method defaultIfEmpty |
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* @owner Observable |
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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 defaultIfEmpty_1.defaultIfEmpty(defaultValue)(this); |
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} |
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exports.defaultIfEmpty = defaultIfEmpty; |
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//# sourceMappingURL=defaultIfEmpty.js.map
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