<@U6647LJ30> is there any updated doc on writing custom serializer? This one uses deprecated code an...

# serialization

[thevery]

@sandwwraith is there any updated doc on writing custom serializer? This one uses deprecated code and doesn't compile: https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/custom_serializers.md#customizing

[thevery]

this note (https://github.com/Kotlin/kotlinx.serialization/blob/4ae3d34a05616d6542eca2b88afc7e30f9a0d9b6/docs/eap13.md#migration-guide) touches migrations a bit, but KSerialClassDesc/SerialDescriptor is still not explained

[thevery]

Looks like https://github.com/Kotlin/kotlinx.serialization/issues/114

[sandwwraith]

SerialDescriptor is briefly explained in KEEP: https://github.com/Kotlin/KEEP/blob/serialization/proposals/extensions/serialization.md#descriptor-of-a-serializable-entity . But indeed, it needs more documentation. Core problem with example that KOutput was split into two interfaces: one which allows writing primitive values, and one which allows write structured data. So, here example assumes that Data would be written as a single String, so it is sufficient to call Encoder.encodeString. You can use also object StringDescriptor as a descriptor

[thevery]

Yes, actually I'm struggling with polymorphic object (not primitive) deserializer - is there any sample for this?

[thevery]

[
            {
              "type": "string",
              "string": "Hello!"
            },
            {
              "type": "datetime",
              "datetime": "2018-10-05T14:36:48.997000+00:00"
            }

]

[sandwwraith]

Probably this https://github.com/Kotlin/kotlinx.serialization/blob/eap13/runtime/common/src/test/kotlin/kotlinx/serialization/CustomSerializersTest.kt#L67 and this https://github.com/Kotlin/kotlinx.serialization/blob/master/runtime/jvm/src/test/kotlin/kotlinx/serialization/formats/json/JsonTreeAndMapperTest.kt#L35 could help you a little to understand how encoder calls should be laid out

[thevery]

wow great links 👍

[thevery]

definitely should be in docs/samples