using a redirect code flow I cannot handleAuthorizationResponse because of the state of the grant

[mnelsonwhite]

Using a redirect code flow will mean that I must recreate the state of the AuthorizationCodeGrant after redirect.

The current implementation makes the state private.

AuthorizationCodeGrant should be changed to be able to recreate the state or remove the state entirely.

You can avoid the risk of calling methods on the grant out of sequence by providing any additionally required state in the method parameters.

  Future<Client> handleAuthorizationResponse(
      Map<String, String> parameters, bool requireState = false) async {

    if (requireState) {
      if (!parameters.containsKey('state')) {
        throw FormatException('Invalid OAuth response for '
            '"$authorizationEndpoint": parameter "state" expected to be '
            '"$_stateString", was missing.');
      } else if (parameters['state'] != _stateString) {
        throw FormatException('Invalid OAuth response for '
            '"$authorizationEndpoint": parameter "state" expected to be '
            '"$_stateString", was "${parameters['state']}".');
      }
    }

    if (parameters.containsKey('error')) {
      var description = parameters['error_description'];
      var uriString = parameters['error_uri'];
      var uri = uriString == null ? null : Uri.parse(uriString);
      throw AuthorizationException(parameters['error']!, description, uri);
    } else if (!parameters.containsKey('code')) {
      throw FormatException('Invalid OAuth response for '
          '"$authorizationEndpoint": did not contain required parameter '
          '"code".');
    }

    return _handleAuthorizationCode(parameters['code']);
  }