Flutter Riverpod: 'read' method and 'timerString' getter not found in BuildContext and CountDownController

Question

I'm building a Pomodoro timer app using Flutter and decided to use Riverpod for state management due to its recommended practices for scalable projects. I've encountered two main issues that block my progress:

BuildContext 'read' Method Error:

When initializing _countDownController in PomodoroIntervals's initState, I get an error saying:

_countDownController = context.read(countDownControllerProvider.notifier);

Error: The method 'read' isn't defined for the type 'BuildContext'.

CountDownController 'timerString' Getter Error:

Attempting to access timerString from _countDownController results in:

if (_countDownController.timerString == '00:00:00') {
   _tabController.animateTo(1, duration: const Duration(milliseconds: 300));
}

Error: The getter 'timerString' isn't defined for the type 'CountDownController'.

Attempted Solutions:

• Checked for correct import of Riverpod packages.
• Searched for similar issues regarding the use of context.read in initState, suspecting a lifecycle problem.
• Looked for a missing definition or import for timerString but found none.

How can I resolve these errors and correctly implement Riverpod for state management in my Flutter app?

Answer 1

That's right, because context has no such parameter. Here's how to do it (and using ConsumerStatefulWidget):

class PomodoroIntervals extends ConsumerStatefulWidget {
  const PomodoroIntervals ({super.key});

  @override
  ConsumerState createState() => _PomodoroIntervalsState();
}

class _PomodoroIntervalsState extends ConsumerState<PomodoroIntervals> {
  @override
  void initState() {
    ...
    _countDownController = ref.read(countDownControllerProvider);
  }

  @override
  Widget build(BuildContext context) {
    ref.watch(myProvider); // and here...
    return Container();
  }
}

The ref instance is available as a field of the ConsumerStatefulWidget class