Using Provider for Simple State Management in Flutter

Introduction

State management is a core concept in Flutter development. As your app grows, passing state down widget trees via constructors becomes tedious. The Flutter Provider package offers a lightweight, efficient way to share and react to state changes. In this tutorial, you’ll learn how to integrate Flutter Provider (and its close variant provider package) for simple state management. By the end, you’ll have a working counter app that updates UI automatically when data changes.

Adding Provider to Your Project

1. Open pubspec.yaml.

2. Add the provider dependency:

dependencies:
  flutter:
    sdk: flutter
  provider

3. Run flutter pub get to install.

4. Import the library in your Dart files:

import 'package:provider/provider.dart';

Creating a ChangeNotifier

Provider uses classes that extend ChangeNotifier to hold mutable state. Below is a simple counter model. Whenever the count updates, listeners are notified, and the UI rebuilds.

import 'package:flutter/foundation.dart';

class CounterModel extends ChangeNotifier {
  int _count = 0;
  int get count => _count;

  void increment() {
    _count++;
    notifyListeners();
  }
}

• _count is private.

• count is a public getter.

• increment() mutates state and calls notifyListeners().

Providing and Consuming State

Wrap your app (or part of it) with a ChangeNotifierProvider. This makes the counter available to any descendant widget.

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'counter_model.dart';

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (_) => CounterModel(),
      child: const MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: const CounterPage(),
    );
  }
}

• create lazily instantiates CounterModel.

• Descendant widgets use context.watch<CounterModel>(), context.read<CounterModel>(), or Consumer<CounterModel>().

Updating the UI

In your CounterPage, display the current count and a button to increment. Use context.watch to rebuild when the model changes, and context.read to call methods without triggering rebuilds.

class CounterPage extends StatelessWidget {
  const CounterPage({super.key});
  @override
  Widget build(BuildContext context) {
    final counter = context.watch<CounterModel>().count;
    return Scaffold(
      appBar: AppBar(title: const Text('Provider Counter')),
      body: Center(child: Text('Count: $counter')),
      floatingActionButton: FloatingActionButton(
        onPressed: () => context.read<CounterModel>().increment(),
        child: const Icon(Icons.add),
      ),
    );
  }
}

• context.watch<CounterModel>().count subscribes to updates.

• context.read<CounterModel>().increment() invokes state change without rebuilding this widget.

Advanced Tips

• Using Consumer wraps only part of the widget tree, limiting rebuild scope.

• For multiple providers, use MultiProvider.

• Consider Selector or ProxyProvider for derived or combined state.

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Conclusion

You’ve set up a minimal Flutter Provider example, created a ChangeNotifier model, and connected it to your UI. This approach scales well: you can add more providers, aggregate data, and keep widgets focused on presentation. Flutter Provider delivers a clear separation between state and UI, enabling predictable and maintainable code.

With this foundation in Flutter Provider, you’re ready to explore more advanced state management patterns and deliver robust, reactive applications. Happy coding!