Class EventEmitter<T>

The EventEmitter class is used to emit events and register listeners. The API is based on the Node.js EventEmitter API.

Aracna Reference

Type Parameters

T extends EventEmitterEvents = EventEmitterEvents

Hierarchy (View Summary)

EventEmitter

Index

Constructors

constructor

new EventEmitter<T extends EventEmitterEvents = EventEmitterEvents>(): EventEmitter<
T,
>
Type Parameters
- T extends EventEmitterEvents = EventEmitterEvents
Returns EventEmitter<T>
- Defined in src/classes/event-emitter.ts:18

Properties

`Protected`listeners

listeners: EventEmitterListener<T, keyof T>[]

`Protected`maxListeners

maxListeners: number

Methods

countListeners

countListeners<K extends string | number | symbol>(
    name?: K,
    callback?: T[K],
    options?: EventEmitterListenerOptions,
): number
Counts the listeners that match the name, callback and options. If no arguments are passed, all listeners will be counted.
Type Parameters
- K extends string | number | symbol
Parameters
- Optionalname: K
- Optionalcallback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns number
- Defined in src/classes/event-emitter.ts:27

emit

emit<K extends string | number | symbol>(
name: K,
...args: Parameters<T[K]>,
): boolean
Emits an event.
Type Parameters
- K extends string | number | symbol
Parameters
- name: K
- ...args: Parameters<T[K]>
Returns boolean
- Defined in src/classes/event-emitter.ts:34

getEventNames

getEventNames(): (keyof T)[]
Returns the names of the events that have listeners.

Returns (keyof T)[]
- Defined in src/classes/event-emitter.ts:56

getListeners

getListeners<K extends string | number | symbol>(
    name?: K,
    callback?: T[K],
    options?: EventEmitterListenerOptions,
): EventEmitterListener<T, keyof T>[]
Returns the listeners that match the name, callback and options. If no arguments are passed, all listeners will be returned.
Type Parameters
- K extends string | number | symbol
Parameters
- Optionalname: K
- Optionalcallback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns EventEmitterListener<T, keyof T>[]
- Defined in src/classes/event-emitter.ts:64

getMaxListeners

getMaxListeners(): number
Returns the maximum number of listeners that can be registered for a single event.

Returns number
- Defined in src/classes/event-emitter.ts:78

hasListeners

hasListeners<K extends string | number | symbol>(
    name?: K,
    callback?: T[K],
    options?: EventEmitterListenerOptions,
): boolean
Checks if the event has listeners that match the name, callback and options.
Type Parameters
- K extends string | number | symbol
Parameters
- Optionalname: K
- Optionalcallback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns boolean
- Defined in src/classes/event-emitter.ts:85

off

off<K extends string | number | symbol>(
    name?: K,
    callback?: T[K],
    options?: EventEmitterListenerOptions,
): this
Removes the listeners that match the name, callback and options. If no arguments are passed, all listeners will be removed.
Type Parameters
- K extends string | number | symbol
Parameters
- Optionalname: K
- Optionalcallback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns this
- Defined in src/classes/event-emitter.ts:93

on

on<K extends string | number | symbol>(
    name: K,
    callback: T[K],
    options?: EventEmitterListenerOptions,
): this
Adds a listener, which will be called when the event is emitted.

Optionally the listener can be removed after the first call with the once option. Optionally the listener can be prepended to the listeners array with the prepend option.
Type Parameters
- K extends string | number | symbol
Parameters
- name: K
- callback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns this
- Defined in src/classes/event-emitter.ts:113

once

once<K extends string | number | symbol>(
    name: K,
    callback: T[K],
    options?: EventEmitterListenerOptions,
): this
Adds a listener, which will be called only once when the event is emitted.
Type Parameters
- K extends string | number | symbol
Parameters
- name: K
- callback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns this
- Defined in src/classes/event-emitter.ts:140

prepend

prepend<K extends string | number | symbol>(
    name: K,
    callback: T[K],
    options?: EventEmitterListenerOptions,
): this
Adds a listener, which will be called first when the event is emitted.
Type Parameters
- K extends string | number | symbol
Parameters
- name: K
- callback: T[K]
- Optionaloptions: EventEmitterListenerOptions
Returns this
- Defined in src/classes/event-emitter.ts:147

setListeners

setListeners(listeners: EventEmitterListener<T, keyof T>[]): this
Sets the listeners.
Parameters
- listeners: EventEmitterListener<T, keyof T>[]
Returns this
- Defined in src/classes/event-emitter.ts:154

setMaxListeners

setMaxListeners(n: number): this
Sets the maximum number of listeners that can be registered for a single event.
Parameters
- n: number
Returns this
- Defined in src/classes/event-emitter.ts:164

Class EventEmitter<T>

Type Parameters

Hierarchy (View Summary)

Index

Constructors

Properties

Methods

Constructors

constructor

Type Parameters

Returns EventEmitter<T>

Properties

Protectedlisteners

ProtectedmaxListeners

Methods

countListeners

Type Parameters

Parameters

Returns number

emit

Type Parameters

Parameters

Returns boolean

getEventNames

Returns (keyof T)[]

getListeners

Type Parameters

Parameters

Returns EventEmitterListener<T, keyof T>[]

getMaxListeners

Returns number

hasListeners

Type Parameters

Parameters

Returns boolean

off

Type Parameters

Parameters

Returns this

on

Type Parameters

Parameters

Returns this

once

Type Parameters

Parameters

Returns this

prepend

Type Parameters

Parameters

Returns this

setListeners

Parameters

Returns this

setMaxListeners

Parameters

Returns this

Settings

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`Protected`listeners

`Protected`maxListeners