Class EventEmitter<EventTypes, Context>

constructor

• new EventEmitter<
      EventTypes extends ValidEventTypes = string
      | symbol,
      Context extends unknown = any,
  >(): EventEmitter<EventTypes, Context>

  Type Parameters

  • EventTypes extends ValidEventTypes = string | symbol
  • Context extends unknown = any

  Returns EventEmitter<EventTypes, Context>

Staticprefixed

addListener

• addListener<T extends string | symbol>(
      event: T,
      fn: EventListener<EventTypes, T>,
      context?: Context,
  ): this

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T
  • fn: EventListener<EventTypes, T>
  • Optionalcontext: Context

  Returns this

emit

• emit<T extends string | symbol>(
      event: T,
      ...args: Parameters<EventListener<EventTypes, T>>,
  ): boolean

  Calls each of the listeners registered for a given event.

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T
  • ...args: Parameters<EventListener<EventTypes, T>>

  Returns boolean

eventNames

• eventNames(): EventNames<EventTypes>[]

  Return an array listing the events for which the emitter has registered listeners.

  Returns EventNames<EventTypes>[]

listenerCount

• listenerCount(event: EventNames<EventTypes>): number

  Return the number of listeners listening to a given event.

  Parameters

  • event: EventNames<EventTypes>

  Returns number

listeners

• listeners<T extends string | symbol>(event: T): EventListener<EventTypes, T>[]

  Return the listeners registered for a given event.

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T

  Returns EventListener<EventTypes, T>[]

off

• off<T extends string | symbol>(
      event: T,
      fn?: EventListener<EventTypes, T>,
      context?: Context,
      once?: boolean,
  ): this

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T
  • Optionalfn: EventListener<EventTypes, T>
  • Optionalcontext: Context
  • Optionalonce: boolean

  Returns this

on

• on<T extends string | symbol>(
      event: T,
      fn: EventListener<EventTypes, T>,
      context?: Context,
  ): this

  Add a listener for a given event.

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T
  • fn: EventListener<EventTypes, T>
  • Optionalcontext: Context

  Returns this

once

• once<T extends string | symbol>(
      event: T,
      fn: EventListener<EventTypes, T>,
      context?: Context,
  ): this

  Add a one-time listener for a given event.

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T
  • fn: EventListener<EventTypes, T>
  • Optionalcontext: Context

  Returns this

removeAllListeners

• removeAllListeners(event?: EventNames<EventTypes>): this

  Remove all listeners, or those of the specified event.

  Parameters

  • Optionalevent: EventNames<EventTypes>

  Returns this

removeListener

• removeListener<T extends string | symbol>(
      event: T,
      fn?: EventListener<EventTypes, T>,
      context?: Context,
      once?: boolean,
  ): this

  Remove the listeners of a given event.

  Type Parameters

  • T extends string | symbol

  Parameters

  • event: T
  • Optionalfn: EventListener<EventTypes, T>
  • Optionalcontext: Context
  • Optionalonce: boolean

  Returns this