ConfigCat SDK for Dart (Flutter)

https://configcat.com

ConfigCat SDK for Dart provides easy integration for your application to ConfigCat.

ConfigCat is a feature flag and configuration management service that lets you separate feature releases from code deployments. You can turn features ON or OFF using the ConfigCat Dashboard even after they are deployed. ConfigCat lets you target specific groups of users based on region, email, or any other custom user attribute.

ConfigCat is a hosted feature flag service that lets you manage feature toggles across frontend, backend, mobile, and desktop apps. Alternative to LaunchDarkly. Management app + feature flag SDKs.

Getting started

1. Install the ConfigCat SDK

With Dart:

dart pub add configcat_client

With Flutter:

flutter pub add configcat_client

Or put the following directly to your pubspec.yml and run dart pub get or flutter pub get.

dependencies:
  configcat_client: ^2.4.0

2. Go to the ConfigCat Dashboard to get your SDK Key:

3. Import the configcat_client package in your application code

import 'package:configcat_client/configcat_client.dart';

4. Create a ConfigCat client instance

final client = ConfigCatClient.get(sdkKey: '#YOUR-SDK-KEY#');

5. (Optional) Set up Flutter caching

If you're using the SDK in a Flutter application, we recommend to use our Flutter Preferences Cache for caching. It's based on the shared_preferences package.

final client = ConfigCatClient.get(
    sdkKey: '#YOUR-SDK-KEY#',
    options: ConfigCatOptions(cache: ConfigCatPreferencesCache()));

6. Get your setting value

final isMyAwesomeFeatureEnabled = await client.getValue(key: 'isMyAwesomeFeatureEnabled', defaultValue: false);
if (isMyAwesomeFeatureEnabled) {
    doTheNewThing();
} else {
    doTheOldThing();
}

7. Close the client on application exit

client.close();

Getting user-specific setting values with Targeting

Using this feature, you will be able to get different setting values for different users in your application by passing a User Object to the getValue() function.

Read more about Targeting here.

User Object

Percentage and targeted rollouts are calculated by the user object passed to the configuration requests. The user object must be created with a mandatory identifier parameter which uniquely identifies each user:

final user = ConfigCatUser(identifier: '#USER-IDENTIFIER#');

final isMyAwesomeFeatureEnabled = await client.getValue(key: 'isMyAwesomeFeatureEnabled', defaultValue: false, user: user);
if (isMyAwesomeFeatureEnabled) {
  doTheNewThing();
} else {
  doTheOldThing();
}

Sample/Demo app

• Sample Console app
• Sample Flutter app

Polling Modes

The ConfigCat SDK supports three different polling mechanisms to acquire the setting values from ConfigCat. After the latest setting values are downloaded, they are stored in an internal cache . After that, all requests are served from the cache. Read more about Polling Modes and how to use them at ConfigCat Dart Docs.

Support

If you need help using this SDK, feel free to contact the ConfigCat Staff at https://configcat.com. We're happy to help.

Contributing

Contributions are welcome. For more info please read the Contribution Guideline.

Contributors

Special thanks to @augustorsouza, @miguelspe, and @mugbug from @quintoandar who made available the initial project.

About ConfigCat

• Official ConfigCat SDKs for other platforms
• Documentation
• Blog