InheritableSerialInfo

annotation class InheritableSerialInfo

Meta-annotation that commands the compiler plugin to handle the annotation as serialization-specific. Serialization-specific annotations are preserved in the SerialDescriptor and can be retrieved during serialization process with SerialDescriptor.getElementAnnotations.

In contrary to regular SerialInfo, this one makes annotations inheritable: If class X marked as Serializable has any of its supertypes annotated with annotation A that has @InheritableSerialInfo on it, A appears in X's SerialDescriptor even if X itself is not annotated. It is possible to use A multiple times on different supertypes. Resulting X's SerialDescriptor.annotations would still contain only one instance of A. Note that if A has any arguments, their values should be the same across all hierarchy. Otherwise, a compilation error would be reported by the plugin.

Example:

@InheritableSerialInfo
annotation class A(val value: Int)

@A(1) // Annotation can also be inherited from interfaces
interface I

@Serializable
@A(1) // Argument value is the same as in I, no compiler error
abstract class Base: I

@Serializable
class Derived: Base()

// This function returns 1.
fun foo(): Int = Derived.serializer().descriptor.annotations.filterIsInstance<A>().single().value

Constructors

Link copied to clipboard
fun InheritableSerialInfo()