Here is my TypeScript code utilizing RxJS:
function getParam(val:any):Observable<any> {
return from(val).pipe(delay(1000))
}
of(1,2,3,4).pipe(
switchMap(val => getParam(val))
).subscribe(val => console.log(val));
I believe that the getParam function should return 'val' within an observable. However, I encounter an error with switchMap stating:
hostReportError.js:5 Uncaught TypeError: You provided '1' where a stream was expected. You can provide an Observable, Promise, Array, or Iterable.
at subscribeTo (subscribeTo.js:39)
at Module.from (from.js:15)
at getParam (index.ts:6)
at SwitchMapSubscriber.eval [as project] (index.ts:8)
at SwitchMapSubscriber._next (switchMap.js:43)
at SwitchMapSubscriber.Subscriber.next (Subscriber.js:63)
at Observable.eval [as _subscribe] (subscribeToArray.js:7)
at Observable._trySubscribe (Observable.js:50)
at Observable.subscribe (Observable.js:36)
at SwitchMapOperator.call (switchMap.js:27)
If I modify the getParam function to:
function getParam(val:any):Observable<any> {
return of(val).pipe(delay(1000))
}
It successfully returns 4. So why does the from operator not return an observable in this scenario?
Edit: This question is distinct from RxJs Observable of vs from because it focuses on the fact that both from and of should be observables. Yet, when using from, switchMap raises an issue about not receiving an observable and simply obtaining '1' from the array. I hope this clarifies the inquiry.