Restart the timer on an rxjs interval

Question

I created a class which sets up a pausable rxjs observable on an interval:

export class RepeatingServiceCall {
  private paused = false;
  private o         


        

Answer 1

You can abandon the old timer on start and start a new one on start.

const { interval, Subject, fromEvent } = rxjs;
const { takeUntil } = rxjs.operators;

let timer$;

const pause = new Subject();

const obs$ = new Subject();

obs$.subscribe(_ => { console.log('Timer fired') });

function start() {
  timer$ = interval(1000);
  timer$.pipe(takeUntil(pause)).subscribe(_ => { obs$.next(); });
}

function stop() {
  pause.next();
  timer$ = undefined;
}

fromEvent(document.getElementById('toggle'), 'click').subscribe(() => {
  if (timer$) {
    stop();
  } else {
    start();
  }
});

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