Hi team, How `refreshTokens` works while using `Au...

# ktor

[Pallaw Pathak]

Hi team, How refreshTokens works while using Auth plugin with bearer provider? In my understanding it should be invoked as soon as server returns 401 in the response. Unfortunately its not working for me. Can anyone please help

code for reference

fun RemoteDataModule() =
    module {
        single<HttpClient> {
            HttpClient {
                // converts response into dto objects
                install(ContentNegotiation) {
                    json(HttpClientUtil.nonStrictJson)
                }

                // Log HTTP request and response
                install(Logging) {
                    logger = HttpClientLogger // custom logger
                    level = LogLevel.ALL
                }.also { initLogger() } // this will initialise napier for both platform

                //Add authentication header in the request
                install(Auth) {
                    bearer {
                        loadTokens {// add BearerTokens in header
                            val appPreferenceDataSource = get<AppPreferencesDataSource>()
                            val accessToken = appPreferenceDataSource.getAccessToken().first() ?: ""
                            val refreshToken = appPreferenceDataSource.getRefreshToken().first() ?: ""

                            BearerTokens(accessToken, refreshToken)
                        }

                        /**
                         * This block is called when API returns 401, UnAuthorized
                         * In that case it will automatically hit the same API with updated token
                         */
                        refreshTokens {
                            // Refresh tokens and return them as the 'BearerTokens' instance
                            val appPreferenceDataSource = get<AppPreferencesDataSource>()
                            val accessToken = appPreferenceDataSource.getAccessToken().first() ?: ""
                            val refreshToken = appPreferenceDataSource.getRefreshToken().first() ?: ""

                            BearerTokens(accessToken, refreshToken)
                        }
                    }
                }

                defaultRequest {
                    // Set the Content-Type header for each request
                    header(HttpHeaders.ContentType, ContentType.Application.Json.toString())
                    header("Client-id", AppConstants.UNIGO_ORG_ID)
                }
            }
        }

        single<KtorApiService> { KtorApiServiceImp(get<HttpClient>()) }
    }

[Alexander Zhirkevich]

It seems like you don't refresh tokens but just load them the same way from cache twice inside load and refresh blocks. You should call the API endpoint for new tokens and save them to the cache.

[Pallaw Pathak]

@Alexander Zhirkevich I am updating the token in cache at success block of token api. I have checked it. The chache is being updated before calling the secured API.
Will it not work this way?

[Aleksei Tirman [JB]]

Can you check that the WWW-Authenticate header is present and contains the Bearer auth scheme?

[Pallaw Pathak]

@Aleksei Tirman [JB] It's not currently present in the header. I'll try once more with the response header as per your suggestion. But is it really needed? According to the official documentation WWW-Authenticate is only needed when multiple providers are used, Otherwise just 401 should be enough to call the refreshToken{} block.
Please correct me if I am wrong here.

Attached is the SS of the official document for reference.

[Aleksei Tirman [JB]]

You're right. Can you please check with the header anyway?

[Pallaw Pathak]

Sure, Will try and let you guys know. Meanwhile, Do you think how we create instance of the client matters in this case? I am using koin for DI and creating the client as single instance. Can it be a problem here?

[Aleksei Tirman [JB]]

It shouldn't be a problem.