Class EventEmitter<CustomEvents>

Type Parameters

Hierarchy (View Summary)

Constructors

constructor

Methods

addListener emit listeners on once removeAllListeners removeListener setMaxListeners guard listenerCount setDefaultMaxListeners

Constructors

constructor

Methods

addListener

  • addListener<
        Type extends string
        | number
        | symbol,
        Callback extends (...args: any) => void,
    >(
        type: Type,
        listener: Callback,
    ): this

  • Type Parameters

    • Type extends string | number | symbol
    • Callback extends (...args: any) => void

    Parameters

    Returns this

    Description

    adds a listener to the end of the listeners array for the specified event.

emit

  • emit<
        Type extends string
        | number
        | symbol,
        Callback extends (...args: any) => void,
    >(
        type: Type,
        ...params: Parameters<Callback>,
    ): boolean

  • Type Parameters

    • Type extends string | number | symbol
    • Callback extends (...args: any) => void

    Parameters

    Returns boolean

    Description

    execute each of the listeners in order with the supplied parameters.

listeners

  • listeners<
        Type extends string
        | number
        | symbol,
        Callback extends (...args: any) => void,
    >(
        type: Type,
    ): Callback[]

  • Type Parameters

    • Type extends string | number | symbol
    • Callback extends (...args: any) => void

    Parameters

    Returns Callback[]

    Description

    returns an array of listeners for the specified event.

on

  • on<
        Type extends string
        | number
        | symbol,
        Callback extends (...args: any) => void,
    >(
        type: Type,
        listener: Callback,
    ): this

  • Type Parameters

    • Type extends string | number | symbol
    • Callback extends (...args: any) => void

    Parameters

    Returns this

    Description

    alias for addListener

once

  • once<
        Type extends string
        | number
        | symbol,
        Callback extends (...args: any) => void,
    >(
        type: Type,
        listener: Callback,
    ): this

  • Type Parameters

    • Type extends string | number | symbol
    • Callback extends (...args: any) => void

    Parameters

    Returns this

    Description

    adds a one time listener for the event. This listener is invoked only the next time the event is fired, after which it is removed.

removeAllListeners

  • removeAllListeners<Type extends string | number | symbol>(type?: Type): this

  • Type Parameters

    • Type extends string | number | symbol

    Parameters

    Returns this

    Description

    removes all listeners, or those of the specified event.

removeListener

  • removeListener<
        Type extends string
        | number
        | symbol,
        Callback extends (...args: any) => void,
    >(
        type: Type,
        listener: Callback,
    ): this

  • Type Parameters

    • Type extends string | number | symbol
    • Callback extends (...args: any) => void

    Parameters

    Returns this

    Description

    remove a listener from the listener array for the specified event.

setMaxListeners

  • setMaxListeners(maxListeners: number): this

  • Parameters

    • maxListeners: number

    Returns this

    Description

    by default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default which helps finding memory leaks. Obviously not all Emitters should be limited to 10. This function allows that limit to be increased. Set to zero for unlimited.

Staticguard

  • guard(cb: Function): void

  • Parameters

    • cb: Function

    Returns void

    Description

    set custom error handler for event listeners

StaticlistenerCount

StaticsetDefaultMaxListeners

  • setDefaultMaxListeners(maxListeners: number): void

  • Parameters

    • maxListeners: number

    Returns void

    Description

    set default amount for limit warning

Settings

Member Visibility

On This Page

Constructors
Methods