sample.d.ts 1.5 KB

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  1. import { Observable } from '../Observable';
  2. import { MonoTypeOperatorFunction } from '../interfaces';
  3. /**
  4. * Emits the most recently emitted value from the source Observable whenever
  5. * another Observable, the `notifier`, emits.
  6. *
  7. * <span class="informal">It's like {@link sampleTime}, but samples whenever
  8. * the `notifier` Observable emits something.</span>
  9. *
  10. * <img src="./img/sample.png" width="100%">
  11. *
  12. * Whenever the `notifier` Observable emits a value or completes, `sample`
  13. * looks at the source Observable and emits whichever value it has most recently
  14. * emitted since the previous sampling, unless the source has not emitted
  15. * anything since the previous sampling. The `notifier` is subscribed to as soon
  16. * as the output Observable is subscribed.
  17. *
  18. * @example <caption>On every click, sample the most recent "seconds" timer</caption>
  19. * var seconds = Rx.Observable.interval(1000);
  20. * var clicks = Rx.Observable.fromEvent(document, 'click');
  21. * var result = seconds.sample(clicks);
  22. * result.subscribe(x => console.log(x));
  23. *
  24. * @see {@link audit}
  25. * @see {@link debounce}
  26. * @see {@link sampleTime}
  27. * @see {@link throttle}
  28. *
  29. * @param {Observable<any>} notifier The Observable to use for sampling the
  30. * source Observable.
  31. * @return {Observable<T>} An Observable that emits the results of sampling the
  32. * values emitted by the source Observable whenever the notifier Observable
  33. * emits value or completes.
  34. * @method sample
  35. * @owner Observable
  36. */
  37. export declare function sample<T>(notifier: Observable<any>): MonoTypeOperatorFunction<T>;