flutter_launch_arguments

A flutter plugin to retrieve Android and iOS launch arguments

Motivation

There are some cases where you need to pass arguments to your app when launching it. Typically, in Flutter you can use --dart-define or --dart-define-from-file to pass arguments to your app. However, these arguments are only available at runtime and not when the app is already installed. This plugin allows you to retrieve the launch arguments on both Android and iOS.

This plugin comes in handy when you need to pass arguments to your app when launching instrumentation tests. For example, you might need to set up a test environment or configure your app in a specific way when running tests. This plugin allows you to pass arguments to your app when launching the tests and retrieve them in your app.

Getting Started

Add the following dependencies to your pubspec.yaml:

dependencies:
  flutter_launch_arguments: latest

Usage

flutter_launch_arguments provides a simple API to retrieve launch arguments from the platform. To get a launch argument, you can use the following methods:

• getString(String key): retrieves a string argument from the launch arguments
• getBool(String key): retrieves a boolean argument from the launch arguments
• getDouble(String key): retrieves a double argument from the launch arguments
• getInt(String key): retrieves an integer argument from the launch arguments

These methods return a Future with the type of the argument you are trying to retrieve. If the argument is not found, the future will return null.

Before using these methods, you need to initialize the plugin by calling FlutterLaunchArguments() which is a singleton.

Example

import 'package:flutter/material.dart';
import 'package:flutter_launch_arguments/flutter_launch_arguments.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late final FlutterLaunchArguments _flutterLaunchArgumentsPlugin;

  @override
  void initState() {
    super.initState();

    _flutterLaunchArgumentsPlugin = FlutterLaunchArguments();
  }

  @override
  Widget build(BuildContext context) =>
      MaterialApp(
        home: Scaffold(
          appBar: AppBar(
            title: const Text('flutter_launch_arguments example app'),
          ),
          body: ListView(
            children: [
              FutureBuilder<String?>(
                future: _flutterLaunchArgumentsPlugin.getString('foo'),
                builder: (context, snapshot) =>
                    ListTile(
                      title: Text('${snapshot.data}'),
                      subtitle: const Text('foo'),
                    ),
              ),
              FutureBuilder<bool?>(
                future: _flutterLaunchArgumentsPlugin.getBool('isFooEnabled'),
                builder: (context, snapshot) =>
                    ListTile(
                      title: Text('${snapshot.data}'),
                      subtitle: const Text('isFooEnabled'),
                    ),
              ),
              FutureBuilder<double?>(
                future: _flutterLaunchArgumentsPlugin.getDouble('fooValue'),
                builder: (context, snapshot) =>
                    ListTile(
                      title: Text('${snapshot.data}'),
                      subtitle: const Text('fooValue'),
                    ),
              ),
              FutureBuilder<int?>(
                future: _flutterLaunchArgumentsPlugin.getInt('fooInt'),
                builder: (context, snapshot) =>
                    ListTile(
                      title: Text('${snapshot.data}'),
                      subtitle: const Text('fooInt'),
                    ),
              ),
            ],
          ),
        ),
      );
}

Passing arguments to the app

Android

To pass arguments to your app on Android, you can use the adb shell am start command. For example:

adb shell am start -n com.example.myapp/com.example.myapp.MainActivity --es foo bar --ez isFooEnabled true --ed fooValue 3.14 --ei fooInt 42

iOS

To pass arguments to your app on iOS, you can use the xcrun simctl command. For example:

xcrun simctl launch booted com.example.myapp -foo bar -isFooEnabled "true" -fooValue 3.14 -fooInt 42

Questions and bugs

Please feel free to submit new issues if you encounter problems while using this library.

If you need help with the use of the library or you just want to request new features, please use the Discussions section of the repository. Issues opened as questions will be automatically closed.

License

flutter_launch_arguments is available under the MIT license. See the LICENSE file for more info.