mu_state #

A set of helpers for pragmatic state handling in Flutter as mentioned in my Medium article .

Features #

A set of classes for handling state based on ValueNotifier and ValueListenableBuilder, where state is wrapped in a MuEvent object:

• MuEvent - state event with data, loading and error fields
• MuState - a ValueNotifier of type MuEvent
• MuBuilder - a ValueListenableBuilder of type MuEvent
• MuMultiBuilder - listen to multiple MuState objects and get notified with a list of MuEvent values

Getting started #

Declare state as a global final MuState variable and pass it an initial MuEvent. Add new MuEvent objects to MuState.value as state changes.

For more complex state handling, extends MuState and implement the necessary logic / methods.

Listen to a single MuState object using MuBuilder.

Listen to multiple MuState objects using MuMultiBuilder, which notifies you with a list of MuEvent values on every state change.

Example #

In test_state.dart:

import 'package:mu_state/mu_state.dart';

class TestState extends MuState<String> {
  TestState(MuEvent<String> value) : super(value);

  void load() async {
    value = const MuEvent.loading();
    await Future.delayed(const Duration(milliseconds: 500));
    value = const MuEvent.data('done');
  }
}

final testState = TestState(const MuEvent.data('initial'));

In main.dart:

Scaffold(
  body: Center(
    child: MuBuilder<String>(
      state: testState,
      builder: (context, event, child) {
        if (event.loading) {
          return const CircularProgressIndicator();
        }
        if (event.hasError) {
          return Text('Error: ${event.error.toString()}');
        }
        return Text('${event.data}');
      },
    ),
  ),
),

Also see Example.

Additional information #

I'd like to keep this packages minimal, but please create an issue if you have a suggestion.

I'm on Twitter as @apptakk