Deserialize a list of generics inside a data class with kotlinx.serialization

Say you have:

@Serializable
data class PagedData<T>(val data: T, val page: Int, val totalPages: Int, val pageSize: Int)

Where you know for sure that T is a class that has the annotations @Serializable or a list of a type that is annotated with @Serializable.

Why the serialization runtime is not able to infer what to use? It would be kind of pointless to explicitly build a serializer before every response as such.

Cross reference on kotlin.serialization issue board

[e5l]

Hi, @lamba92. I reproduced the problem on the server, it will be fixed in the next minor release.

[monxalo]

Don’t know if this is new or not but with a combination of Plugin generated generic serializer with Serializers module this is possible.

@Serializable
data class Item(val entry: String)

@Serializable
data class PagedData<T>(val data: T, val page: Int, val totalPages: Int, val pageSize: Int)

// in Application.module()

json(json = Json {
    serializersModule = SerializersModule {
        contextual(PagedData.serializer(Item.serializer()))
    }
})

With these changes on your response in ktor you no longer need to serialize the object in call.response() method to a String