44 lines
2.1 KiB
JavaScript
44 lines
2.1 KiB
JavaScript
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import { withLatestFrom as higherOrder } from '../operators/withLatestFrom';
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/* tslint:enable:max-line-length */
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/**
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* Combines the source Observable with other Observables to create an Observable
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* whose values are calculated from the latest values of each, only when the
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* source emits.
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*
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* <span class="informal">Whenever the source Observable emits a value, it
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* computes a formula using that value plus the latest values from other input
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* Observables, then emits the output of that formula.</span>
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*
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* <img src="./img/withLatestFrom.png" width="100%">
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*
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* `withLatestFrom` combines each value from the source Observable (the
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* instance) with the latest values from the other input Observables only when
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* the source emits a value, optionally using a `project` function to determine
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* the value to be emitted on the output Observable. All input Observables must
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* emit at least one value before the output Observable will emit a value.
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*
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* @example <caption>On every click event, emit an array with the latest timer event plus the click event</caption>
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* var clicks = Rx.Observable.fromEvent(document, 'click');
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* var timer = Rx.Observable.interval(1000);
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* var result = clicks.withLatestFrom(timer);
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* result.subscribe(x => console.log(x));
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*
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* @see {@link combineLatest}
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*
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* @param {ObservableInput} other An input Observable to combine with the source
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* Observable. More than one input Observables may be given as argument.
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* @param {Function} [project] Projection function for combining values
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* together. Receives all values in order of the Observables passed, where the
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* first parameter is a value from the source Observable. (e.g.
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* `a.withLatestFrom(b, c, (a1, b1, c1) => a1 + b1 + c1)`). If this is not
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* passed, arrays will be emitted on the output Observable.
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* @return {Observable} An Observable of projected values from the most recent
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* values from each input Observable, or an array of the most recent values from
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* each input Observable.
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* @method withLatestFrom
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* @owner Observable
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*/
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export function withLatestFrom(...args) {
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return higherOrder(...args)(this);
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}
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//# sourceMappingURL=withLatestFrom.js.map
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