Need some help here to serialize a property in a c...

# serialization

[pajatopmr]

Need some help here to serialize a property in a class that is a list of an interface. Specifically at line 47 I need to add something like @Serializable(with = ????) val list: List<Stuff>. But what ???? is is eluding me.

[diesieben07]

Check out the docs on polymorphism: https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/polymorphism.md

[pajatopmr]

You mean for the hundredth time?

[diesieben07]

It should lead you here: https://kotlin.github.io/kotlinx.serialization/kotlinx-serialization-core/kotlinx-serialization-core/kotlinx.serialization/-polymorphic-serializer/index.html
It shows how to deal with this

[pajatopmr]

Not that I can see. I've read this page many times. What would be more helpful, and something I could not find is an example of encoding a property that is an array of an interface. The PolymorphicSerializer doc page only shows how to deal with a list of class, not a list of an interface. List of class is working for me, not list of interface, at least not yet.

[diesieben07]

An interface itself cannot be serialized, you need to specify list of possible subclasses as seen in the docs for PolymorphicSerializer

[pajatopmr]

Hmmm. You might be right. I'll mull that one for a bit ... is this a limitation for collections? I can certainly serialize interfaces that are not collections as long as the implementations are registered using a polymorphic serializer like JsonContentPolymorphicSerializer. Use that all the time. This is my first attempt with a collection of an interface.

[pajatopmr]

It turns out you can serialize a list of interfaces, as I was trying to do. The solution comes from @Sergey Shanshin on Github and is hugely appreciated!