带去抖动的 BehaviorSubject 订阅

Question

I have BehaviorSubject property

public results$ = new BehaviorSubject(null);

Lets'say I have a subscription to this

this.results$.subscribe(() => this.find());

Subscription in being invoked each time when I press any key on keyboards inside input element. So, to prevent many requests to the server, I added debounceTime()

this.results$
   .pipe(debounceTime(500))
   .subscribe(() => this.find());

But I need to invoke the first this.find() without any debounce, just immediately.

How can I do that?

Answer 1

I would suggest you to use throttleTime instead of debounceTime. It propagates the first value and then wait for the specified amount of time.

Also change the BehaviorSubject to Subject .

public results$ = new Subject();

this.results$
   .pipe(
         filter(value => !!value && value.length >= 3),
         throttleTime(500))
   .subscribe(() => this.find());

Please read about throttleTime, auditTime and debounceTime here - https://rxjs-dev.firebaseapp.com/guide/operators