Hi all. Using KotlinX, how do I serialize or desarialize a generic attribute? ```@Serializable data ...

# serialization

[Rodrigo Silva]

Hi all. Using KotlinX, how do I serialize or desarialize a generic attribute?

@Serializable
data class Test<T>(
val attr: T
)

[Adam S]

either pass in a serializer for T manually
https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/serializers.md#plugin-generated-generic-serializer

or define a custom serializer
https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/serializers.md#custom-serializers-for-a-generic-type

or set up contextual serialization
https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/serializers.md#contextual-serialization-and-generic-classes

[Rodrigo Silva]

Thanks @Adam S
But i have another question
How do I serializer and deserializer this class

@Serializable(with = BoxSerializer::class)
data class Box<T>(
val name: String
val contents: T
)

Im lost here

override fun deserialize(decoder: Decoder) = Box(dataSerializer.deserialize(decoder))

[Adam S]

Generics can be really difficult with KxS, so I understand what you mean.

What can T be? Do you have a class for it?

[Rodrigo Silva]

I'm using a messenger system. The stream follows publish the command-> read the command

@Serializable
data class Command <T> (
 @Serializeble(KUUID::class) val id: UUID,
  val status: CommandStatusEnum,
   val message: T
)

enum class CommandStatusEnum(val value: String) {
  Open("Open"),
  Closed("Closed"),
  Processing("Processing"),
  Error("Error")
}

object KUUID : KSerializer<UUID> {
  override val descriptor = PrimitiveSerialDescriptor("UUID", PrimitiveKind.STRING)
  override fun serialize(encoder: Encoder, value: UUID) = encoder.encodeString(value.toString())
  override fun deserialize(decoder: Decoder): UUID = UUID.fromString(decoder.decodeString())
}

the message can be any class, such as pro example, email class

@Serializable
data class EmailModel(
  @Serializable(KUUID::class) override val id: UUID,
  val active: Boolean,
  val address: String,
  @Serializable(KUUID::class) val associateFK: UUID
)

[Adam S]

are the messages in JSON?

[Adam S]

Can you add a discriminator into the message types? It’s difficult for KxS to try and figure out how to decode something if it doesn’t know what the type is

[Adam S]

@Serializable
data class Command <T> (
  val status: CommandStatusEnum,
  val messageType: MessageType,
  val message: T
)

[Rodrigo Silva]

I will convert the objects to jsonObject,

[Rodrigo Silva]

my question, is, when I have a class, with more than one attribute, how does that line

override fun deserialize(decoder: Decoder) = Box(dataSerializer.deserialize(decoder))

[Rodrigo Silva]

override fun deserialize(decoder: Decoder) = Command((string, enum,  dataSerializer.deserialize(decoder))