While testing, refactoring and future-proofing a customers project, I stumbled over this little deprecation notification:
Will be removed in v9 or v10. Use repeat's delay option instead.
repeatWhen(notifier: (notifications: Observable) => Observable): MonoTypeOperatorFunction
Simple enough, right? But when I tried, I didn't find a simple way to do so. I have a rough idea how I could hack it. But that's not exactly what I'd like to hand over to a customer as "improved" code. So what obvious path do I fail to see, that leads from this (straight out of the rxjs documentation):
import { of, fromEvent, repeatWhen } from 'rxjs';
const source = of('Repeat message');
const documentClick$ = fromEvent(document, 'click');
***const result = source.pipe(repeatWhen(() => documentClick$));***
result.subscribe(data => console.log(data))
to this:
import { of, fromEvent, repeat } from 'rxjs';
const source = of('Repeat message');
const documentClick$ = fromEvent(document, 'click');
const result = source.pipe(repeat({ delay: ??? () => documentClick$) });
result.subscribe(data => console.log(data))
How to switch an option that accepts a number into an option that repeats whenever the event happens? Well, as said, I have an idea how to achieve it, but it would be incredibly ugly. So what am I missing?
You almost got it right, just remove the question marks :)
source.pipe(repeat({ delay: () => documentClick$ }));
This basically says "Whenever source completes, subscribe to documentClick$ and whenever this (documentClick$) emits, re-subscribe to source.
Did you want to do more with that? I didn't fully understand your last paragraph.
In my little example, where a mouse click is faked by a timer, I get an emission every 2 seconds:
import { of, repeat, timer } from 'rxjs';
const source = of('Repeat message');
const documentClick$ = timer(2000);
const result = source.pipe(repeat({ delay: () => documentClick$ }));
result.subscribe((data) => console.log(data));