I need to deserialize 2 versions of an entity `Entity` : one with all properties, and another `Simpl...

# serialization

[tseisel]

I need to deserialize 2 versions of an entity Entity : one with all properties, and another SimpleEntity with only the most used properties from Entity. How can I do that? I thought of using closed polymorphism but I can't use a discriminator because I don't control the input JSON.

[diesieben07]

You could use `JsonContentPolymorphicSerializer`: https://kotlin.github.io/kotlinx.serialization/kotlinx-serialization-json/kotlinx-serialization-json/kotlinx.serialization.json/-json-content-polymorphic-serializer/index.html

[tseisel]

Does this mean that I only have to define the following 2 classes
• open class SimpleEntity(val foo: String, ...)
• class Entity(foo: String, val bar: Int) : SimpleEntity(foo)
and the dedicated implementation of JsonContentPolymorphicSerializer ?

[diesieben07]

Yes

[tseisel]

Alright, I should give it a try. Many thanks for your answers!

[tseisel]

I noticed that the custom serializer is not necessary for deserialization as long as I specify the expected subclass explicitly.
However it's currently not possible to have a @Serializable class extend from a @Serializable open class ; I ended up using a sealed class as base.