firebase-dataconnect/com.google.firebase.dataconnect/OptionalVariable

OptionalVariable

@Serializable(with = OptionalVariable.Serializer::class)

sealed interface OptionalVariable<out T>(source)

A variable of an operation that may be left undefined, which is distinct from null: an Undefined variable is not sent to the server at all (and takes the operation's default), a Value is sent even when it holds null.

Inheritors

Undefined

Value

Types

Serializer

class Serializer<T>(elementSerializer: KSerializer<T>) : KSerializer<OptionalVariable<T>>

Serializes a Value with elementSerializer and an Undefined as nothing at all, so that the field is absent from the encoded variables. Only encoders that tolerate an element encoding nothing support this (the tree encoder of kotlinx-serialization-json does, its streaming encoder does not). Decoding is not supported, as variables are only ever sent.

Undefined

object Undefined : OptionalVariable<Nothing>

The undefined variable: omitted when the variables are serialized.

Value

class Value<T>(val value: T) : OptionalVariable<T>

A defined variable, possibly holding null.

Functions

valueOrNull

abstract fun valueOrNull(): T?

The value, or null when undefined.

valueOrThrow

abstract fun valueOrThrow(): T

The value; throws when undefined.