Hey all. I'm trying to use this data class and get...

# serialization

[Shan]

Hey all. I'm trying to use this data class and getting this response:
j.b.u: Can't locate argument-less serializer for class e.b.b.d.a (Kotlin reflection is not available). For generic classes, such as lists, please provide serializer explicitly.

Can anyone confirm that this means I have to write my own serializer because it's using a Map? Or is there a way to do this that I'm missing somewhere? I'm using this with a Ktor request.

Untitled

[Dominaezzz]

That's weird. You shouldn't need a custom serializer.

[Dominaezzz]

It should just work.

[Dominaezzz]

This is for json right?

[Shan]

Yeah

[Shan]

just setting up Ktor like so:

install(JsonFeature) {
    serializer = KotlinxSerializer()
}

[Shan]

I have another request class I am using that involves an Array. Should that just work out of box as well?

@Serializable
data class Request(
    val flags: Array<String>,
    val userInfo: UserAttributes
)

[Shan]

UserAttributes:

@Serializable
data class UserAttributes(
    val booleanAttributes: Map<String, Boolean>,
    val numberAttributes: Map<String, Float>,
    val stringAttributes: Map<String, String>
)

[Shan]

Not quite sure from the error message which data class is having the problem unfortunately, I think it's getting eaten by ProGuard

[Dominaezzz]

Yes the Array one should work as well.

[Dominaezzz]

Maybe proguard is the issue?

[Shan]

The issue I was having is that Ktor wasn't using the generated serializer() from Kotlinx.Serialization, and was instead trying to use reflection to find it but could not. I set it explicitly with setMapper(KClass, KSerializer) and it is now working, though I do wonder why Ktor does not find the KSerializer without me explicitly setting it seeing as it is always generated when something is annotated with @serialized.. 🤔