Listenable Interface

An object which allows the registration of listeners so that subscribers can be notified when an event happens.

Sealed

This type is "sealed," meaning that code outside of the library defining it should not implement or extend it. Future versions of this type may add members or make typing of readonly members more specific.

Signature

/** @sealed */
export interface Listenable<TListeners extends object>

Type Parameters

Parameter	Constraint	Description
TListeners	object

Methods

Method	Return Type	Description
off(eventName, listener)	void	Deregister an event listener.
on(eventName, listener)	Off

Method Details

off

Deregister an event listener.

Signature

off<K extends keyof Listeners<TListeners>>(eventName: K, listener: TListeners[K]): void;

Type Parameters

Parameter	Constraint	Description
K	keyof Listeners<TListeners>

Remarks

If listener is not currently registered, this method will have no effect.

Listeners may also be deregistered by calling the deregistration function returned when they are registered.

Parameters

Parameter	Type	Description
eventName	K	The name of the event.
listener	TListeners[K]	The listener function to remove from the current set of event listeners.

on

Signature

on<K extends keyof Listeners<TListeners>>(eventName: K, listener: TListeners[K]): Off;

Type Parameters

Parameter	Constraint	Description
K	keyof Listeners<TListeners>

Parameters

Parameter	Type	Description
eventName	K
listener	TListeners[K]

Returns

Return type: Off