Hi, Is it possible to use generated serializer and custom deserializer for some data class?

yes, that’s possible

How it can be achieved?

that’s quite a large question to ask! The docs are a good start https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/serializers.md but if something’s not working you need to be more specific https://codeblog.jonskeet.uk/2010/08/29/writing-the-perfect-question/

I was able to implement this by surrogate serializer but I would like avoid this method.

Something like this should work:

@Serializable(with = MyClass.Serializer::class)
data class MyClass(val prop: Int) {
    @Serializer(forClass = MyClass::class)
    object Serializer : KSerializer<MyClass> {
        override fun deserialize(decoder: Decoder): MyClass {
            // custom logic here
        }
    }
}

(I've not tested it in a IDE and just wrote in Slack. Probably there is some syntax error or so) You might ask, why this works. Well, the

@Serializer

annotation generates the KSerializer, but skips those methods, that are implemented manually. In this case the deserialize method is defined manually, so the plugin just generates the serialize method and the descriptor.

It works. Thanks!

You can add something like this:

@Serializer(forClass = MyClass::class)
private object OriginalSerializer : KSerializer<MyClass>

Inside the

deserialize

from the

Serializer

object, you can then use

OriginalSerializer.deserialize(decoder)

.