Is there a way to have a sync function that subscribes to an observable within it?

Issue

Assuming I have this code

observableMethod(): Observably { ... Return of([1, 2, 3]); }

notObservableMethod(): integer {

Let myVal;

if (isOM) { this.observableMethod().pipe( first() ).subscribe( val => myVal = val; }); } else { myVal = this.nonAsyncMethod(); }

return myVal * 5; }

What can I do to notObservableMethod so it can return myVal * 5;? Meaning it has to be a syncronous method?

Edit: In reality, val is a url and I have a postProcess for that url that is more complex in the example I posted above before I navigate to it. Currently, what I did is create another method for the post process then call it in each condition or in a subscribe if its observable but I was thinking if there's a better way of doing it. Thank you!

Solution

Since I am not entirely sure I understand the whole snippet, I'll try to guide you based on your example. I was trying to figure out if there could be a better way by using some RxJS operators along the way, before you subscribe, or a async$ pipe in your template.

I would change your code above to something like this:

observableMethod(): Observably { ... Return of([1, 2, 3]); }

notObservableMethod(): Observable<number> {

  const observableSource = isOM ? this.observableMethod() : Observable.of(nonAsyncMethod());

  return observableSource.pipe(first(), map(val => val * 5)); 
}

Answered By - Eren Yeager