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49 lines
1.9 KiB
49 lines
1.9 KiB
"use strict"; |
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var elementAt_1 = require('../operators/elementAt'); |
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/** |
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* Emits the single value at the specified `index` in a sequence of emissions |
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* from the source Observable. |
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* |
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* <span class="informal">Emits only the i-th value, then completes.</span> |
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* |
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* <img src="./img/elementAt.png" width="100%"> |
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* |
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* `elementAt` returns an Observable that emits the item at the specified |
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* `index` in the source Observable, or a default value if that `index` is out |
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* of range and the `default` argument is provided. If the `default` argument is |
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* not given and the `index` is out of range, the output Observable will emit an |
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* `ArgumentOutOfRangeError` error. |
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* |
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* @example <caption>Emit only the third click event</caption> |
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* var clicks = Rx.Observable.fromEvent(document, 'click'); |
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* var result = clicks.elementAt(2); |
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* result.subscribe(x => console.log(x)); |
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* |
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* // Results in: |
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* // click 1 = nothing |
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* // click 2 = nothing |
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* // click 3 = MouseEvent object logged to console |
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* |
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* @see {@link first} |
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* @see {@link last} |
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* @see {@link skip} |
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* @see {@link single} |
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* @see {@link take} |
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* |
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* @throws {ArgumentOutOfRangeError} When using `elementAt(i)`, it delivers an |
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* ArgumentOutOrRangeError to the Observer's `error` callback if `i < 0` or the |
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* Observable has completed before emitting the i-th `next` notification. |
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* |
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* @param {number} index Is the number `i` for the i-th source emission that has |
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* happened since the subscription, starting from the number `0`. |
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* @param {T} [defaultValue] The default value returned for missing indices. |
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* @return {Observable} An Observable that emits a single item, if it is found. |
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* Otherwise, will emit the default value if given. If not, then emits an error. |
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* @method elementAt |
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* @owner Observable |
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*/ |
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function elementAt(index, defaultValue) { |
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return elementAt_1.elementAt(index, defaultValue)(this); |
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} |
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exports.elementAt = elementAt; |
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//# sourceMappingURL=elementAt.js.map
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