authentication intercepto retry

authentication_interceptor_retry.dart

import 'package:app/data/storage/auth/auth_shared_references.dart';
import 'package:app/domain/repository/auth_repo.dart';
import 'package:dio/dio.dart';
import 'package:kiwi/kiwi.dart';

class AuthenticationInterceptor extends Interceptor{
  final Dio _dio;

  AuthenticationInterceptor(this._dio);
  
  AuthSharedPreferences _authSharedPreferences = KiwiContainer().resolve<AuthSharedPreferences>();

  @override
  Future onRequest(RequestOptions options) async {
	String token = await _authSharedPreferences.getAccessToken();
	options.headers.addAll({'Authorization': 'Bearer $token'});
	return super.onRequest(options);

  }

  @override
  Future onError(DioError dioError) async{
	var resp = dioError.response;
	if (resp == null) {
	  return super.onError(dioError);
	}
	
	//#1: get http response status code
	int responseCode = resp.statusCode;
	
	//#2: check accessToken & refreshToken
	String oldAccessToken = await _authSharedPreferences.getAccessToken();
	String refreshToken = await _authSharedPreferences.getRefreshToken();
	if (oldAccessToken != null && refreshToken != null && responseCode == 401) {
	  
	  //#3: lock
	  _dio.interceptors.requestLock.lock();
	  _dio.interceptors.responseLock.lock();

	  //#5: invoked refreshToken api
	  AuthRepo _authRepo = KiwiContainer().resolve<AuthRepo>();
	  var refreshSuccess = await _authRepo.refreshAuth(refreshToken);

	  //#4 unlock
	  _dio.interceptors.requestLock.unlock();
	  _dio.interceptors.responseLock.unlock();

	  if (refreshSuccess == true) {
	    //#6: retry request which is failed
		RequestOptions options = dioError.response.request;
		return _dio.request(options.path, options: options);
	  }
	}

	return super.onError(dioError);
  }

  @override
  Future onResponse(Response response) {
	return super.onResponse(response);
  }
}

class RestClient{
  final Dio restClient = Dio();

  void setUp() {
	restClient.interceptors.addAll([AuthenticationInterceptor(restClient)]);
  }
}