reactivestate-core/com.ensody.reactivestate/ContextualVal

ContextualVal

class ContextualVal<T>(val name: String, var default: (CoroutineContext) -> T)

A val for which the value can be set via the coroutineContext.

This is similar to a thread-local or the "dynamic scope" concept.

The default value is created lazily on demand per CoroutineScope (not globally!). For this to work you have to inject ContextualValRoot into each CoroutineScope that wants to support this class.

The name is only used to help with debugging.

Also see ContextualValSuspend for a suspend based version.

Constructors

ContextualVal

constructor(name: String, default: (CoroutineContext) -> T)

Types

ContextElement

class ContextElement<T>(val key: ContextualVal.ContextKey<T>, valueGetter: (CoroutineContext) -> T) : CoroutineContext.Element

ContextKey

class ContextKey<T>(val value: ContextualVal<T>) : CoroutineContext.Key<ContextualVal.ContextElement<T>>

Properties

default

var default: (CoroutineContext) -> T

key

val key: ContextualVal.ContextKey<T>

name

val name: String

Functions

get

suspend fun get(): T

Gets the value for the current coroutineContext.

fun get(context: CoroutineContext): T

Gets the value for the given context.

fun get(scope: CoroutineScope): T

Gets the value for the given scope.

toString

open override fun toString(): String

valued

fun valued(block: (CoroutineContext) -> T): CoroutineContext.Element

The returned CoroutineContext.Element can used to set a value via CoroutineScope.plus.

with

suspend fun <R> with(value: T, block: suspend () -> R): R

Sets a new value that only exists within block.