HierarchySerializer

A serializer which will delegate (de)serialization to a serializer for a subtype of T based on a string property in a node.

Instances can be constructed either using the default constructor (passing in a map directly) or using a simple DSL model to define subtypes (Model). If unspecified, the default key of the type node is TYPE_KEY.

This serializer must be added through TypeSerializerCollection.Builder.registerExact instead of register!

Callers must provide a map of strings to subtypes with which nodes will be deserialized:

interface Base
class Foo(val a: Int) : Base
class Bar(val b: String) : Base

HierarchySerializer<Base>( // `<Base>` can be excluded
  mapOf(
    "foo" to Foo::class.java,
    "bar" to Bar::class.java,
  ),
)
// or
HierarchySerializer<Base> {
  // use `_` to omit the `Base` type parameter
  subType<_, Foo>("foo")
  subType<_, Bar>("bar")
}

Assuming a structure like:

data class Root(
  val items: ArrayList<Base>,
)

With the typeKey as TYPE_KEY, a possible serialized form would be:

{
  "items": [
    {
      "type": "foo",
      "a": 3
    },
    {
      "type": "bar",
      "b": "hello"
    }
  ]
}