authorize static method

Future<bool> authorize({ BuildContext? context, required String clientID, required String clientSecret, required String redirectUri, required String callbackUrlScheme, required bool isSandbox, })

Method that implements the OAuth 2.0 protocol and gets (and retain) in the SharedPreferences the access and refresh tokens from Dexcom APIs.

Implementation

static Future<bool> authorize(
    {BuildContext? context,
    required String clientID,
    required String clientSecret,
    required String redirectUri,
    required String callbackUrlScheme,
    required bool isSandbox}) async {
  // Instantiate Dio and its Response
  Dio dio = Dio();
  Response response;

  // Generate the Dexcom url
  final dexcomAuthorizeFormUrl = DexcomAuthAPIURL.authorizeForm(
      redirectUri: redirectUri, clientID: clientID, isSandbox: isSandbox);

  // Perform authentication
  try {
    final result = await FlutterWebAuth.authenticate(
        url: dexcomAuthorizeFormUrl.url,
        callbackUrlScheme: callbackUrlScheme);
    //Get the auth code
    final code = Uri.parse(result).queryParameters['code'];

    // Generate the Dexcom url
    final dexcomAuthorizeUrl = DexcomAuthAPIURL.authorize(
        redirectUri: redirectUri,
        code: code!,
        clientID: clientID,
        clientSecret: clientSecret,
        isSandbox: isSandbox);

    response = await dio.post(
      dexcomAuthorizeUrl.url,
      data: dexcomAuthorizeUrl.data,
      options: Options(
        contentType: Headers.formUrlEncodedContentType,
      ),
    );

    // Debugging
    final logger = Logger();
    logger.i('$response');

    // Save authorization tokens
    final accessToken = response.data['access_token'] as String;
    final refreshToken = response.data['refresh_token'] as String;
    final expires = response.data['expires_in'] as int;

    GetIt.instance<SharedPreferences>()
        .setString('dexcomAccessToken', accessToken);
    GetIt.instance<SharedPreferences>()
        .setString('dexcomRefreshToken', refreshToken);
    GetIt.instance<SharedPreferences>()
        .setString('dexcomTokenExpires', Formats.fullDateFormat.format(DateTime.now().add(Duration(seconds: expires))));
    GetIt.instance<SharedPreferences>()
        .setString('dexcomRedirectUri', redirectUri);
  } catch (e) {
    print(e);
  } // catch

  return true;
}