How to use refershToken in ktor-CodePudding

Hey I am working in kotlin multiplatform moblie. I want to ask that if api returns 401 status, I want to call refresh api. I am reading the doc to configure ktor but unable to understand this. Can someone guide me on this. I tried some code in my side, Can some one guide me any proper example how to achieve in my solution.

commonMain

expect fun httpClient(config: HttpClientConfig<*>.() -> Unit = {}): HttpClient

iOSMain

actual class Platform actual constructor() {
    actual val versionCode =
        platform.Foundation.NSBundle.mainBundle.infoDictionary?.get("CFBundleVersion").toString()
    actual val accessToken = ""
}

androidMain

actual fun httpClient(config: HttpClientConfig<*>.() -> Unit) = HttpClient(OkHttp) {
    config(this)
    install(ContentNegotiation) {
        json(Json {
            prettyPrint = true
            ignoreUnknownKeys = true
            explicitNulls = false
        })
    }
    engine {
        config {
            retryOnConnectionFailure(true)
            connectTimeout(30, TimeUnit.SECONDS)
            readTimeout(40, TimeUnit.SECONDS)
        }
    }
    defaultRequest {
        header("Client-Version", Platform().versionCode)
    }
    HttpResponseValidator {
        validateResponse { response ->
            when (response.status.value) {
                401 -> {

                }
            }
        }
    }
    install(Auth) {
        bearer {
            loadTokens {
                BearerTokens(tokenProvider.accessToken, "")
            }
        }
    }
}

Platform.kt

package com.example.kotlinmultiplatformsharedmodule

lateinit var provider: VersionAndroidProvider
lateinit var tokenProvider: AndroidToken

actual class Platform actual constructor() {
    actual val versionCode get() = provider.version
    actual val accessToken: String
        get() = tokenProvider.accessToken
}

interface VersionAndroidProvider {
    val version: String
}

interface AndroidToken {
    val accessToken: String
}

I need to call api, if api returns 401 status, I need to call refershToken api. After getting new accessToken from refreshToken api, I need to send this to api call.

If refreshToken is giving 401 then I need to infrom my application to logout.

CodePudding user response：

If you use the Bearer provider in Ktor’s Authentication plugin then the refreshTokens lambda will be called when a server returns 401. For more information read the documentation. Here is an incomplete example for your use case:

val client = HttpClient(Apache) {
    install(Auth) {
        bearer {
            loadTokens {
                BearerTokens("initial_access_token", "initial_refresh_token")
            }

            refreshTokens {
                val response = client.get("https://example.com/get_token")

                if (response.status == HttpStatusCode.Unauthorized) {
                    // logout
                    null
                } else {
                    // get token from a response
                    BearerTokens("new_access_token", "new_refresh_token")
                }
            }
        }
    }
}