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91 lines
3.1 KiB
91 lines
3.1 KiB
"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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var ArgumentOutOfRangeError_1 = require('../util/ArgumentOutOfRangeError'); |
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var EmptyObservable_1 = require('../observable/EmptyObservable'); |
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/** |
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* Emits only the first `count` values emitted by the source Observable. |
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* |
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* <span class="informal">Takes the first `count` values from the source, then |
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* completes.</span> |
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* |
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* <img src="./img/take.png" width="100%"> |
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* |
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* `take` returns an Observable that emits only the first `count` values emitted |
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* by the source Observable. If the source emits fewer than `count` values then |
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* all of its values are emitted. After that, it completes, regardless if the |
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* source completes. |
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* |
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* @example <caption>Take the first 5 seconds of an infinite 1-second interval Observable</caption> |
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* var interval = Rx.Observable.interval(1000); |
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* var five = interval.take(5); |
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* five.subscribe(x => console.log(x)); |
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* |
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* @see {@link takeLast} |
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* @see {@link takeUntil} |
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* @see {@link takeWhile} |
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* @see {@link skip} |
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* |
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* @throws {ArgumentOutOfRangeError} When using `take(i)`, it delivers an |
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* ArgumentOutOrRangeError to the Observer's `error` callback if `i < 0`. |
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* |
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* @param {number} count The maximum number of `next` values to emit. |
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* @return {Observable<T>} An Observable that emits only the first `count` |
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* values emitted by the source Observable, or all of the values from the source |
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* if the source emits fewer than `count` values. |
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* @method take |
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* @owner Observable |
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*/ |
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function take(count) { |
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return function (source) { |
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if (count === 0) { |
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return new EmptyObservable_1.EmptyObservable(); |
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} |
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else { |
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return source.lift(new TakeOperator(count)); |
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} |
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}; |
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} |
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exports.take = take; |
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var TakeOperator = (function () { |
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function TakeOperator(total) { |
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this.total = total; |
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if (this.total < 0) { |
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throw new ArgumentOutOfRangeError_1.ArgumentOutOfRangeError; |
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} |
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} |
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TakeOperator.prototype.call = function (subscriber, source) { |
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return source.subscribe(new TakeSubscriber(subscriber, this.total)); |
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}; |
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return TakeOperator; |
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}()); |
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/** |
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* We need this JSDoc comment for affecting ESDoc. |
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* @ignore |
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* @extends {Ignored} |
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*/ |
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var TakeSubscriber = (function (_super) { |
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__extends(TakeSubscriber, _super); |
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function TakeSubscriber(destination, total) { |
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_super.call(this, destination); |
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this.total = total; |
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this.count = 0; |
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} |
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TakeSubscriber.prototype._next = function (value) { |
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var total = this.total; |
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var count = ++this.count; |
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if (count <= total) { |
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this.destination.next(value); |
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if (count === total) { |
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this.destination.complete(); |
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this.unsubscribe(); |
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} |
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} |
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}; |
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return TakeSubscriber; |
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}(Subscriber_1.Subscriber)); |
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//# sourceMappingURL=take.js.map
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