mu_state #

A minimal state solution based on my Pragmatic state handling in Flutter Medium article .

Features #

A set of classes built on ValueNotifier and ValueListenableBuilder.

• MuEvent - the base class for our 3 state object
• MuEventData - the data state
• MuEventError - the error state
• MuEventLoading - the loading state
• MuState - a ValueNotifier of type MuEvent
• MuBuilder - a ValueListenableBuilder of type MuEvent
• MuMultiBuilder - listen to a list of MuState's and get notified with a list of MuEvent's

How To #

Declare state as a global final MuState variable and pass it an initial MuEvent type, e.g. a MuEventLoading or a MuEventData.

Alternatively extend MuState and implement the necessary methods.

Listen to MuState changes using MuBuilder.

Listen to multiple MuState objects using MuMultiBuilder and handle the list of MuEvent's on changes.

Example #

In test_state.dart:

import 'package:mu_state/mu_state.dart';

class CounterState extends MuState {
  CounterState(MuEvent initValue) : super(initValue);

  void increment() {
    value = MuEventData((value as MuEventData<int>).data + 1);
  }
}

final counterState = CounterState(const MuEventData<int>(0));

In main.dart:

Scaffold(
  body: Center(
    child: MuBuilder(
      state: counterState,
      builder: (context, event, child) {
        return switch (event) {
          MuEventLoading _ => const CircularProgressIndicator(),
          MuEventError ev => Text('Error: ${ev.error}'),
          MuEventData ev => Text('${ev.data}')
        };
      },
    ),
  ),
),

Also see Example.