Hi, how can I create a serialiazer for an Enum whe...

# serialization

[Ayfri]

Hi, how can I create a serialiazer for an Enum where it would serialize as an int (from the value field, using an interface to ensure that field exists), and deserialize as the enum value

For now I have the serializer working and it was pretty easy, but what should be the deserializer ?

[ephemient]

if you're not using Enum.ordinal or Enum.name you have to build your own reverse mapping

[Ayfri]

And is there a way to get the enum values within the deserializer ?

[ephemient]

not from the descriptor, but if you pass in the enum class then sure

[Ayfri]

@Serializable
sealed interface EnumAsInt {
	val value: Int
}

class EnumAsIntSerializer<T>(private val enum: T) : KSerializer<T> where T : EnumAsInt, T : Enum<*> {
	override val descriptor = Int.serializer().descriptor

	override fun deserialize(decoder: Decoder): T {
		return enum::class.java.enumConstants.first { it.value == decoder.decodeInt() }
	}
	
	override fun serialize(encoder: Encoder, value: T) {
		encoder.encodeInt(value.value)
	}
}

Is this right ?

[ephemient]

no

[ephemient]

well, I suppose you could do that, but you don't have a way to register that serializer

[Ayfri]

Ah, then I didn't understood how to pass the enum class 🤔

[ephemient]

abstract class EnumAsIntSerializer<T : EnumAsInt>(private val values: Array<T>) { ... }

@Serializable(with = MyEnum.Serializer::class)
enum class MyEnum : EnumAsInt {
    object Serializer : EnumAsIntSerializer<MyEnum>(enumValues())
}

[Ayfri]

okay I see, thanks !