স্কিপ করে মূল কন্টেন্ট এ যাও

Getting started

Try Riverpod online​

To get a feel of Riverpod, try it online on Dartpad or on Zapp:

Installing the package​

Once you know what package you want to install, proceed to add the dependency to your app in a single line like this:

flutter pub add \
  flutter_riverpod \
  riverpod_annotation \
  dev:riverpod_generator \
  dev:build_runner \
  dev:custom_lint \
  dev:riverpod_lint

Alternatively, you can manually add the dependency to your app from within your pubspec.yaml:

pubspec.yaml
name: my_app_name
environment:
  sdk: ">=3.0.0 <4.0.0"
  flutter: ">=3.0.0"

dependencies:
  flutter:
    sdk: flutter
  flutter_riverpod: ^2.4.3
  riverpod_annotation: ^2.2.0

dev_dependencies:
  build_runner:
  custom_lint:
  riverpod_generator: ^3.0.0-dev.3
  riverpod_lint: ^2.3.0

Then, install packages with flutter pub get.

You can now run the code-generator with dart run build_runner watch.

That's it. You've added Riverpod to your app!

Enabling riverpod_lint/custom_lint​

Riverpod comes with an optional riverpod_lint package that provides lint rules to help you write better code, and provide custom refactoring options.

The package should already be installed if you followed the previous steps, but a separate step is necessary to enable it.

To enable riverpod_lint, you need add an analysis_options.yaml placed next to your pubspec.yaml and include the following:

analysis_options.yaml
analyzer:
  plugins:
    - custom_lint

You should now see warnings in your IDE if you made mistakes when using Riverpod in your codebase.

To see the full list of warnings and refactorings, head to the riverpod_lint page.

note

Those warnings will not show-up in the dart analyze command.
If you want to check those warnings in the CI/terminal, you can run the following:

dart run custom_lint

Usage example: Hello world​

Now that we have installed Riverpod, we can start using it.

The following snippets showcase how to use our new dependency to make a "Hello world":

lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:riverpod_annotation/riverpod_annotation.dart';

part 'main.g.dart';

// We create a "provider", which will store a value (here "Hello world").
// By using a provider, this allows us to mock/override the value exposed.
@riverpod
String helloWorld(HelloWorldRef ref) {
  return 'Hello world';
}

void main() {
  runApp(
    // For widgets to be able to read providers, we need to wrap the entire
    // application in a "ProviderScope" widget.
    // This is where the state of our providers will be stored.
    ProviderScope(
      child: MyApp(),
    ),
  );
}

// Extend ConsumerWidget instead of StatelessWidget, which is exposed by Riverpod
class MyApp extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final String value = ref.watch(helloWorldProvider);

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('Example')),
        body: Center(
          child: Text(value),
        ),
      ),
    );
  }
}

Then, start the application with flutter run.
This will render "Hello world" on your device.

Going further: Installing code snippets​

If you are using Flutter and VS Code , consider using Flutter Riverpod Snippets

If you are using Flutter and Android Studio or IntelliJ, consider using Flutter Riverpod Snippets

img

Choose your next step​

Learn some basic concepts:

Follow a cookbook: