Flutter OAuth

A Flutter OAuth package for performing user authentication for your apps.

I've tested this with a small collection of APIs (Buffer, Strava, Unsplash and GitHub). If there is an issue with an API you are trying to work with, please file an issue :)

Authorizing an application

Performing authorization for an API is straight forward using this library. In most cases you will just be able to use the following approach:

final OAuth flutterOAuth = new FlutterOAuth(new Config(
    "https://unsplash.com/oauth/authorize",
    "https://unsplash.com/oauth/token",
    "YOUR_CLIENT_ID",
    "YOUR_CLIENT_SECRET",
    "http://localhost:8080",
    "code"));

This allows you to pass in an Authorization URL, Token request URL, Client ID, Client Secret, Redirect URL and the response type. This should satisfy most requests, but if not then you can pass in other optional parameters for:

• contentType - This allows you to change the content type for the request. For example, for Spotify API authorization you need to use "application/x-www-form-urlencoded"

final OAuth flutterOAuth = new FlutterOAuth(new Config(
    ...,
    contentType: "application/x-www-form-urlencoded"));

• parameters - Add your own parameters that this library may not support out-of-the-box. For example, with the GitHub API you can send a state string and scopes to gain authorization for

Map<String, String> customParameters = {"state": "SOME_RANDOM_SECURE_STRING", "scope": "public_repo"};

final OAuth flutterOAuth = new FlutterOAuth(new Config(
    ...,
    parameters: customParameters));

• headers - Some APIs require you to send custom headers, such as an Authorization Header. Use this parameter if you require this

Map<String, String> headers = {"Authorization": "Basic SOME_BASE_64_STRING"};

final OAuth flutterOAuth = new FlutterOAuth(new Config(
    ...,
    headers: headers));

Then once you have an OAuth instance, you can simply call the performAuthorization() method like so to retrieve a Token instance:

Token token = await flutterOauth.performAuthorization();
String accessToken = token.accessToken;

Installing

Add the following you your pubspec.yaml dependancies:

dependencies:
  flutter_oauth: "^0.0.1"

Thanks to

Kevin Seqaud for his awesome blog post on Flutter OAuth https://medium.com/@segaud.kevin/facebook-oauth-login-flow-with-flutter-9adb717c9f2e

The author, Hadrien Lejard, behind the:

The Gitter-Dart repo, where a lot of this library was influenced

and the Flutter Webview plugin, which this library uses