Wait for an async operation in onNext of RxJS Observable

Question

I have an RxJS sequence being consumed in the normal manner...

However, in the observable \'onNext\' handler, some of the operations will complete synchronously, but oth

Answer 1

Another simple example to do manual async operations.

Be aware that it is not a good reactive practice ! If you only want to wait 1000ms, use Rx.Observable.timer or delay operator.

someObservable.flatMap(response => {
  return Rx.Observable.create(observer => {
    setTimeout(() => {
      observer.next('the returned value')
      observer.complete()
    }, 1000)
  })
}).subscribe()

Now, replace setTimeout by your async function, like Image.onload or fileReader.onload ...