KVar

class KVar<T>(initialValue: T) : KVal<T> (source)

A KVar is an observable container for a value of type T. It must be initialized with initialValue, and this can then be modified by setting the KVar.value property. Listeners may be added using KVar.addListener, and these will be called whenever the value is changed.

From within Kweb's DSL, you can use the ElementCreator.kvar function to create a KVar without needing to import KVar, and which will also call KVar.close when this part of the DOM is cleaned up.

Constructors

KVar

constructor(initialValue: T)

Properties

path

val KVar<URL>.path: KVar<String>

pathQueryFragment

val KVar<URL>.pathQueryFragment: KVar<String>

Given the URI specification:

pathSegments

val KVar<URL>.pathSegments: KVar<List<String>>

query

val KVar<URL>.query: KVar<String?>

value

open override var value: T

The current value of this KVar. Setting this property to a different value will notify all listeners, but if the new value is the same as the old value then it will be ignored.

Functions

addListener

fun addListener(listener: (T, T) -> Unit): Long

Add a listener to this KVar. The listener will be called whenever the value property changes.

attr

infix fun KVar<String>.attr(s: String): KVal<String>

open override fun close()

fun close(reason: CloseReason)

Close this KVal, and notify all handlers that it has been closed.

get

operator fun <T : Any> KVar<List<T>>.get(pos: Int): KVar<T>

KVar extensions

operator fun <K : Any, V : Any> KVar<Map<K, V>>.get(k: K): KVar<V?>

map

fun <O> map(mapper: (T) -> O): KVal<O>

Create another KVal that is a mapping of this KVal. The mapping function will be called whenever this KVal changes, and the new KVal will be updated with the result of the mapping function.

fun <O> map(reversibleFunction: ReversibleFunction<T, O>): KVar<O>

Create another KVar that is a bi-directional mapping of this KVar. ReversibleFunction.invoke will be called whenever this KVar changes, and the new KVar will be updated with the result of this mapping function.

notNull