doOnListen method

Observable<T> doOnListen (
  1. void onListen(
      )
    )

    Invokes the given callback function when the stream is first listened to.

    Example

    new Observable.just(1)
  .doOnListen(() => print("Is someone there?"))
  .listen(null); // prints "Is someone there?"

    Implementation

    Observable<T> doOnListen(void onListen()) =>
    transform(DoStreamTransformer<T>(onListen: onListen));