Bloc: Flutter 1.17 and bloc 4.00 update: Transform isn't a valid override

[Luppakorva]

Being a complete novice I can't seem to figure this out. I had:

Stream<ActivityEvent> transform(Stream<ActivityEvent> events) { return (events as Observable<ActivityEvent>) .debounce(Duration(milliseconds: 500)); }

In earlier version which worked perfect, however now I'm getting both:

• Transform not being valid override
• Observable isn't a type so it can't be used in an 'as' expression

Any help would be much appreciated, at total loss why this happens (have tried to read the change logs but not skilled enough to get it)

[felangel]

Hi @Luppakorva 👋
Thanks for opening an issue!

There are two transforms in v4.0.0 (transformEvents and transformTransitions).

In your case, you can replace your code with:

  @override
  Stream<Transition<ActivityEvent, ActivityState>> transformEvents(
    Stream<ActivityEvent> events,
    TransitionFunction<ActivityEvent, ActivityState> transitionFn,
  ) {
    return super.transformEvents(
      events.debounceTime(const Duration(milliseconds: 500)),
      transitionFn,
    );
  }

Hope that helps 👍

[Luppakorva]

Thank you so much for the quick reply and sorry to bother with a follow up,

events.debounceTime is not playing ball, instead getting:

error: The method 'debounceTime' isn't defined for the type 'Stream'.

Any chance you could hint me to right direction why this happens?

[felangel]

You need to make sure you add rxdart as a dependency and import it.

[Luppakorva]

Many many thanks! You saved my night :).