OptionalVariable

@Serializable(with = OptionalVariable.Serializer)
interfaceOptionalVariable<T : Any?>

An optional variable to a query or a mutation.

The typical use case of this class is as a property of a class used as the variables of a query or mutation (OperationRef.variables). This allows omitting a variable altogether from the request, in the case ofOptionalVariable.Undefined, allowing the variable to take on its default value as defined in the GraphQL schema or operation, or an explicit value in the case ofOptionalVariable.Value, which may benull if the type parameter is nullable.

Here is an example of such a variables class:

@Serializable
dataclassUpdatePersonVariables(
valkey:PersonKey,
valname:OptionalVariable<String>,
valage:OptionalVariable<Int?>,
)

with this "variables" class, to clear a person's age but not modify their name, the instance could be created as follows

valvariables=UpdatePersonVariables(
key=key,
name=OptionalVariable.Undefined,
age=OptionalVariable.Value(42),
)

Summary

fun valueOrNull(): T?

fun valueOrThrow(): T