I have an issue with ktor-client on iOS, where I g...

# multiplatform

[galex]

I have an issue with ktor-client on iOS, where I get the following error:

kotlin.NotImplementedError: An operation is not implemented: Obtaining serializer from KClass is not available on native due to the lack of reflection. Use .serializer() directly on serializable class.
        at 0   mu51k-ios                           0x0000000108ff28a5 kfun:kotlin.Error.<init>(kotlin.String?)kotlin.Error + 21
        at 1   mu51k-ios                           0x00000001090f8bd5 kfun:kotlin.NotImplementedError.<init>(kotlin.String)kotlin.NotImplementedError + 21
        at 2   mu51k-ios                           0x0000000109134802 kfun:[e-mail]<#GENERIC_kotlin.Any>.()Generic + 226
        at 3   mu51k-ios                           0x00000001091342c1 kfun:[e-mail]<#GENERIC_kotlin.Any>.()Generic + 97
        at 4   mu51k-ios                           0x000000010913e9b0 kfun:[e-mail].(kotlin.reflect.KClass<#GENERIC_kotlin.Any>)Generic + 144
        at 5   mu51k-ios                           0x000000010913dbf8

It’s weird because the type response the API returns is indeed registered:

actual val networkHttpClient: HttpClient
    get() = HttpClient {
        install(JsonFeature) {
            serializer = KotlinxSerializer().apply {
                setMapper(CheckEmailResponse::class, CheckEmailResponse.serializer())
                setMapper(AuthResponse::class, AuthResponse.serializer())
                setMapper(ActionResponse::class, ActionResponse.serializer())
            }
        }
    }

Does this error mean the http-client doesn’t know what to do with String? Are we supposed to register simple types ourselves?

[galex]

@sandwwraith Hi, what could be the reasons for the serialiser to fail although I did set up the correct class in iOS? The network request looks like this

val address = Url("$baseUrl/$API/$AUTH/$CREATE")
        GlobalScope.launch(backgroundDispatcher) {
            val result: AuthResponse = <http://networkHttpClient.post|networkHttpClient.post> {
                url(address.toString())
                body = TextContent(
                    Json.stringify(CreateAccountParameters(email, password, reEnterPassword)),
                    contentType = ContentType.Application.Json
                )
            }

            GlobalScope.launch(foregroundDispatcher) {
                block(result)
            }
        }

Any help would be greatly appreciated!

[Lawik]

Does your response class contain generics?

[galex]

Nope, here is that class:

@Serializable
data class AuthResponse(val token: String, val userId: Int? = null)

[galex]

@Lawik @sandwwraith Found the issue, finally. I used Json.stringify(CreateAccountParameters(email, password, reEnterPassword)) instead of Json.stringify(CreateAccountParameters.serializer(), CreateAccountParameters(email, password, reEnterPassword)),. Gosh that was a difficult one to find…

[galex]

@Lawik @sandwwraith Will serializers always have to be defined manually for iOS? Is there a planned enhancement where there is no need to do so?

[sandwwraith]

Exception message contains phrase Use .serializer() directly on serializable class., or was it missing?

Unfortunately, there is a very limited possibilities to enhance this since reflection is almost impossible on Native

[galex]

@sandwwraith It was there indeed. Was confused me in this case is that it was not on the receiving part but on the sending part, when I called Json.stringify(…). Understood, so it’s better to always use .serializer and if so, better to do it in the common code already for all platforms. correct?

[sandwwraith]

Yes

[galex]

Cool, thanks