RyanlinkManager

Defined in: src/core/Manager.ts:12

Extends

• EventEmitter

Type Parameters

Type Parameter	Default type
CustomPlayerT extends Player	Player

Constructors

Constructor

new RyanlinkManager<CustomPlayerT>(options: RyanConfiguration<CustomPlayerT>): RyanlinkManager<CustomPlayerT>;

Defined in: src/core/Manager.ts:194

Parameters

Parameter	Type
options	RyanConfiguration<CustomPlayerT>

Returns

RyanlinkManager<CustomPlayerT>

Overrides

EventEmitter.constructor

Properties

Property (defined in)	Type	Default value	Description
initiated (src/core/Manager.ts:51)	boolean	false
nodeManager (src/core/Manager.ts:41)	NodeManager	undefined
options (src/core/Manager.ts:39)	RyanConfiguration<CustomPlayerT>	undefined
players (src/core/Manager.ts:53)	MiniMap<string, CustomPlayerT>	undefined
utils (src/core/Manager.ts:43)	RyanlinkUtils	undefined
voiceStates (src/core/Manager.ts:45)	Map<string, { channelId: string; deaf: boolean; guildId: string; mute: boolean; userId: string; }>	undefined
captureRejections (node_modules/@types/node/events.d.ts:425)	boolean	undefined	Value: boolean Change the default captureRejections option on all new EventEmitter objects. Since v13.4…
captureRejectionSymbol (node_modules/@types/node/events.d.ts:418)	typeof captureRejectionSymbol	undefined	Value: Symbol.for('nodejs.rejection') See how to write a custom rejection handler. Since v13.4.0, v12.16.0
defaultMaxListeners (node_modules/@types/node/events.d.ts:464)	number	undefined	By default, a maximum of 10 listeners can be registered for any single event. This limit can be changed for individual EventEmitter instances using the emitter.setMaxListeners(n) method. To chan…
errorMonitor (node_modules/@types/node/events.d.ts:411)	typeof errorMonitor	undefined	This symbol shall be used to install a listener for only monitoring 'error' events. Listeners installed using this symbol are called before the regular 'error' listeners are called. Installing a l…

Accessors

useable

Get Signature

get useable(): boolean;

Defined in: src/core/Manager.ts:276

Returns

boolean

Methods

[captureRejectionSymbol]()?

optional [captureRejectionSymbol]<K>(
   error: Error,
   event: string | symbol, ...
   args: AnyRest): void;

Defined in: node_modules/@types/node/events.d.ts:103

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
error	Error
event	string | symbol
…args	AnyRest

Returns

void

Inherited from

EventEmitter.[captureRejectionSymbol]

---

addListener()

addListener<K>(eventName: string | symbol, listener: (...args: any[]) => void): this;

Defined in: node_modules/@types/node/events.d.ts:642

Alias for emitter.on(eventName, listener).

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
eventName	string | symbol
listener	(…args: any[]) => void

Returns

this

Since

v0.1.26

Inherited from

EventEmitter.addListener

---

createPlayer()

createPlayer(options: PlayerOptions): CustomPlayerT;

Defined in: src/core/Manager.ts:223

Parameters

Parameter	Type
options	PlayerOptions

Returns

CustomPlayerT

---

deletePlayer()

deletePlayer(guildId: string): boolean | void;

Defined in: src/core/Manager.ts:259

Parameters

Parameter	Type
guildId	string

Returns

boolean | void

---

destroyPlayer()

destroyPlayer(guildId: string, destroyReason?: string): Promise<void | CustomPlayerT>;

Defined in: src/core/Manager.ts:251

Parameters

Parameter	Type
guildId	string
destroyReason?	string

Returns

Promise<void | CustomPlayerT>

---

emit()

emit<Event>(event: Event, ...args: Parameters<ManagerEvents<CustomPlayerT>[Event]>): boolean;

Defined in: src/core/Manager.ts:13

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener

Type Parameters

Type Parameter
Event extends keyof ManagerEvents<CustomPlayerT>

Parameters

Parameter	Type
event	Event
…args	Parameters<ManagerEvents<CustomPlayerT>[Event]>

Returns

boolean

Since

v0.1.26

Overrides

EventEmitter.emit

---

eventNames()

eventNames(): (string | symbol)[];

Defined in: node_modules/@types/node/events.d.ts:967

Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

Returns

(string | symbol)[]

Since

v6.0.0

Inherited from

EventEmitter.eventNames

---

getMaxListeners()

getMaxListeners(): number;

Defined in: node_modules/@types/node/events.d.ts:819

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.

Returns

number

Since

v1.0.0

Inherited from

EventEmitter.getMaxListeners

---

getPlayer()

getPlayer(guildId: string): CustomPlayerT;

Defined in: src/core/Manager.ts:219

Parameters

Parameter	Type
guildId	string

Returns

CustomPlayerT

---

getVoiceStateUsers()

getVoiceStateUsers(guildId: string, channelId: string): object[];

Defined in: src/core/Manager.ts:47

Parameters

Parameter	Type
guildId	string
channelId	string

Returns

object[]

---

init()

init(clientData: BotClientOptions): Promise<RyanlinkManager<CustomPlayerT>>;

Defined in: src/core/Manager.ts:280

Parameters

Parameter	Type
clientData	BotClientOptions

Returns

Promise<RyanlinkManager<CustomPlayerT>>

---

listenerCount()

listenerCount<K>(eventName: string | symbol, listener?: Function): number;

Defined in: node_modules/@types/node/events.d.ts:913

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

Type Parameters

Type Parameter
K

Parameters

Parameter	Type	Description
eventName	string | symbol	The name of the event being listened for
listener?	Function	The event handler function

Returns

number

Since

v3.2.0

Inherited from

EventEmitter.listenerCount

---

listeners()

listeners<K>(eventName: string | symbol): Function[];

Defined in: node_modules/@types/node/events.d.ts:832

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
eventName	string | symbol

Returns

Function[]

Since

v0.1.26

Inherited from

EventEmitter.listeners

---

off()

off<Event>(event: Event, listener: ManagerEvents<CustomPlayerT>[Event]): this;

Defined in: src/core/Manager.ts:28

Alias for emitter.removeListener().

Type Parameters

Type Parameter
Event extends keyof ManagerEvents<CustomPlayerT>

Parameters

Parameter	Type
event	Event
listener	ManagerEvents<CustomPlayerT>[Event]

Returns

this

Since

v10.0.0

Overrides

EventEmitter.off

---

on()

on<Event>(event: Event, listener: ManagerEvents<CustomPlayerT>[Event]): this;

Defined in: src/core/Manager.ts:20

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Type Parameters

Type Parameter
Event extends keyof ManagerEvents<CustomPlayerT>

Parameters

Parameter	Type	Description
event	Event	-
listener	ManagerEvents<CustomPlayerT>[Event]	The callback function

Returns

this

Since

v0.1.101

Overrides

EventEmitter.on

---

once()

once<Event>(event: Event, listener: ManagerEvents<CustomPlayerT>[Event]): this;

Defined in: src/core/Manager.ts:24

Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Type Parameters

Type Parameter
Event extends keyof ManagerEvents<CustomPlayerT>

Parameters

Parameter	Type	Description
event	Event	-
listener	ManagerEvents<CustomPlayerT>[Event]	The callback function

Returns

this

Since

v0.3.0

Overrides

EventEmitter.once

---

prependListener()

prependListener<K>(eventName: string | symbol, listener: (...args: any[]) => void): this;

Defined in: node_modules/@types/node/events.d.ts:931

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Type Parameter
K

Parameters

Parameter	Type	Description
eventName	string | symbol	The name of the event.
listener	(…args: any[]) => void	The callback function

Returns

this

Since

v6.0.0

Inherited from

EventEmitter.prependListener

---

prependOnceListener()

prependOnceListener<K>(eventName: string | symbol, listener: (...args: any[]) => void): this;

Defined in: node_modules/@types/node/events.d.ts:947

Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Type Parameter
K

Parameters

Parameter	Type	Description
eventName	string | symbol	The name of the event.
listener	(…args: any[]) => void	The callback function

Returns

this

Since

v6.0.0

Inherited from

EventEmitter.prependOnceListener

---

provideVoiceUpdate()

provideVoiceUpdate(data:
  | ChannelDeletePacket
  | VoiceState
  | VoiceServer
| VoicePacket): Promise<void>;

Defined in: src/core/Manager.ts:309

Parameters

Parameter	Type
data	| ChannelDeletePacket | VoiceState | VoiceServer | VoicePacket

Returns

Promise<void>

---

rawListeners()

rawListeners<K>(eventName: string | symbol): Function[];

Defined in: node_modules/@types/node/events.d.ts:863

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
eventName	string | symbol

Returns

Function[]

Since

v9.4.0

Inherited from

EventEmitter.rawListeners

---

removeAllListeners()

removeAllListeners(eventName?: string | symbol): this;

Defined in: node_modules/@types/node/events.d.ts:803

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

Parameter	Type
eventName?	string | symbol

Returns

this

Since

v0.1.26

Inherited from

EventEmitter.removeAllListeners

---

removeListener()

removeListener<Event>(event: Event, listener: ManagerEvents<CustomPlayerT>[Event]): this;

Defined in: src/core/Manager.ts:32

Removes the specified listener from the listener array for the event named eventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them fromemit() in progress. Subsequent events behave as expected.

import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indices of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

import { EventEmitter } from 'node:events';
const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Type Parameter
Event extends keyof ManagerEvents<CustomPlayerT>

Parameters

Parameter	Type
event	Event
listener	ManagerEvents<CustomPlayerT>[Event]

Returns

this

Since

v0.1.26

Overrides

EventEmitter.removeListener

---

search()

search(
   query: SearchQuery,
   requestUser?: unknown,
   node?:
  | RyanlinkNode
  | NodeLinkNode,
throwOnEmpty?: boolean): Promise<SearchResult>;

Defined in: src/core/Manager.ts:235

Parameters

Parameter	Type	Default value
query	SearchQuery	undefined
requestUser?	unknown	undefined
node?	| RyanlinkNode | NodeLinkNode	undefined
throwOnEmpty?	boolean	false

Returns

Promise<SearchResult>

---

setMaxListeners()

setMaxListeners(n: number): this;

Defined in: node_modules/@types/node/events.d.ts:813

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

Parameter	Type
n	number

Returns

this

Since

v0.3.5

Inherited from

EventEmitter.setMaxListeners

---

toJSON()

toJSON(): object;

Defined in: src/core/Manager.ts:211

Returns

object

Name	Type	Defined in
initiated	boolean	src/core/Manager.ts:213
nodeCount	number	src/core/Manager.ts:215
playerCount	number	src/core/Manager.ts:214

---

addAbortListener()

static addAbortListener(signal: AbortSignal, resource: (event: Event) => void): Disposable;

Defined in: node_modules/@types/node/events.d.ts:403

Listens once to the abort event on the provided signal.

Listening to the abort event on abort signals is unsafe and may lead to resource leaks since another third party with the signal can call e.stopImmediatePropagation(). Unfortunately Node.js cannot change this since it would violate the web standard. Additionally, the original API makes it easy to forget to remove listeners.

This API allows safely using AbortSignals in Node.js APIs by solving these two issues by listening to the event such that stopImmediatePropagation does not prevent the listener from running.

Returns a disposable so that it may be unsubscribed from more easily.

import { addAbortListener } from 'node:events';

function example(signal) {
  let disposable;
  try {
    signal.addEventListener('abort', (e) => e.stopImmediatePropagation());
    disposable = addAbortListener(signal, (e) => {
      // Do something when signal is aborted.
    });
  } finally {
    disposable?.[Symbol.dispose]();
  }
}

Parameters

Parameter	Type
signal	AbortSignal
resource	(event: Event) => void

Returns

Disposable

Disposable that removes the abort listener.

Since

v20.5.0

Inherited from

EventEmitter.addAbortListener

---

getEventListeners()

static getEventListeners(emitter: EventEmitter<DefaultEventMap> | EventTarget, name: string | symbol): Function[];

Defined in: node_modules/@types/node/events.d.ts:325

Returns a copy of the array of listeners for the event named eventName.

For EventEmitters this behaves exactly the same as calling .listeners on the emitter.

For EventTargets this is the only way to get the event listeners for the event target. This is useful for debugging and diagnostic purposes.

import { getEventListeners, EventEmitter } from 'node:events';

{
  const ee = new EventEmitter();
  const listener = () => console.log('Events are fun');
  ee.on('foo', listener);
  console.log(getEventListeners(ee, 'foo')); // [ [Function: listener] ]
}
{
  const et = new EventTarget();
  const listener = () => console.log('Events are fun');
  et.addEventListener('foo', listener);
  console.log(getEventListeners(et, 'foo')); // [ [Function: listener] ]
}

Parameters

Parameter	Type
emitter	EventEmitter<DefaultEventMap> | EventTarget
name	string | symbol

Returns

Function[]

Since

v15.2.0, v14.17.0

Inherited from

EventEmitter.getEventListeners

---

getMaxListeners()

static getMaxListeners(emitter: EventEmitter<DefaultEventMap> | EventTarget): number;

Defined in: node_modules/@types/node/events.d.ts:354

Returns the currently set max amount of listeners.

For EventEmitters this behaves exactly the same as calling .getMaxListeners on the emitter.

For EventTargets this is the only way to get the max event listeners for the event target. If the number of event handlers on a single EventTarget exceeds the max set, the EventTarget will print a warning.

import { getMaxListeners, setMaxListeners, EventEmitter } from 'node:events';

{
  const ee = new EventEmitter();
  console.log(getMaxListeners(ee)); // 10
  setMaxListeners(11, ee);
  console.log(getMaxListeners(ee)); // 11
}
{
  const et = new EventTarget();
  console.log(getMaxListeners(et)); // 10
  setMaxListeners(11, et);
  console.log(getMaxListeners(et)); // 11
}

Parameters

Parameter	Type
emitter	EventEmitter<DefaultEventMap> | EventTarget

Returns

number

Since

v19.9.0

Inherited from

EventEmitter.getMaxListeners

---

listenerCount()

static listenerCount(emitter: EventEmitter, eventName: string | symbol): number;

Defined in: node_modules/@types/node/events.d.ts:297

A class method that returns the number of listeners for the given eventName registered on the given emitter.

import { EventEmitter, listenerCount } from 'node:events';

const myEmitter = new EventEmitter();
myEmitter.on('event', () => {});
myEmitter.on('event', () => {});
console.log(listenerCount(myEmitter, 'event'));
// Prints: 2

Deprecated

Since v3.2.0 - Use listenerCount instead.

Parameters

Parameter	Type	Description
emitter	EventEmitter	The emitter to query
eventName	string | symbol	The event name

Returns

number

Since

v0.9.12

Inherited from

EventEmitter.listenerCount

---

on()

Call Signature

static on(
   emitter: EventEmitter,
   eventName: string | symbol,
options?: StaticEventEmitterIteratorOptions): AsyncIterator<any[]>;

Defined in: node_modules/@types/node/events.d.ts:270

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
});

for await (const event of on(ee, 'foo')) {
  // The execution of this inner block is synchronous and it
  // processes one event at a time (even with await). Do not use
  // if concurrent execution is required.
  console.log(event); // prints ['bar'] [42]
}
// Unreachable here

Returns an AsyncIterator that iterates eventName events. It will throw if the EventEmitter emits 'error'. It removes all listeners when exiting the loop. The value returned by each iteration is an array composed of the emitted event arguments.

An AbortSignal can be used to cancel waiting on events:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ac = new AbortController();

(async () => {
  const ee = new EventEmitter();

  // Emit later on
  process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
  });

  for await (const event of on(ee, 'foo', { signal: ac.signal })) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
  }
  // Unreachable here
})();

process.nextTick(() => ac.abort());

Use the close option to specify an array of event names that will end the iteration:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
  ee.emit('close');
});

for await (const event of on(ee, 'foo', { close: ['close'] })) {
  console.log(event); // prints ['bar'] [42]
}
// the loop will exit after 'close' is emitted
console.log('done'); // prints 'done'

Parameters

Parameter	Type
emitter	EventEmitter
eventName	string | symbol
options?	StaticEventEmitterIteratorOptions

Returns

AsyncIterator<any[]>

An AsyncIterator that iterates eventName events emitted by the emitter

Since

v13.6.0, v12.16.0

Inherited from

EventEmitter.on

Call Signature

static on(
   emitter: EventTarget,
   eventName: string,
options?: StaticEventEmitterIteratorOptions): AsyncIterator<any[]>;

Defined in: node_modules/@types/node/events.d.ts:275

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
});

for await (const event of on(ee, 'foo')) {
  // The execution of this inner block is synchronous and it
  // processes one event at a time (even with await). Do not use
  // if concurrent execution is required.
  console.log(event); // prints ['bar'] [42]
}
// Unreachable here

Returns an AsyncIterator that iterates eventName events. It will throw if the EventEmitter emits 'error'. It removes all listeners when exiting the loop. The value returned by each iteration is an array composed of the emitted event arguments.

An AbortSignal can be used to cancel waiting on events:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ac = new AbortController();

(async () => {
  const ee = new EventEmitter();

  // Emit later on
  process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
  });

  for await (const event of on(ee, 'foo', { signal: ac.signal })) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
  }
  // Unreachable here
})();

process.nextTick(() => ac.abort());

Use the close option to specify an array of event names that will end the iteration:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
  ee.emit('close');
});

for await (const event of on(ee, 'foo', { close: ['close'] })) {
  console.log(event); // prints ['bar'] [42]
}
// the loop will exit after 'close' is emitted
console.log('done'); // prints 'done'

Parameters

Parameter	Type
emitter	EventTarget
eventName	string
options?	StaticEventEmitterIteratorOptions

Returns

AsyncIterator<any[]>

An AsyncIterator that iterates eventName events emitted by the emitter

Since

v13.6.0, v12.16.0

Inherited from

EventEmitter.on

---

once()

Call Signature

static once(
   emitter: EventEmitter,
   eventName: string | symbol,
options?: StaticEventEmitterOptions): Promise<any[]>;

Defined in: node_modules/@types/node/events.d.ts:184

Creates a Promise that is fulfilled when the EventEmitter emits the given event or that is rejected if the EventEmitter emits 'error' while waiting. The Promise will resolve with an array of all the arguments emitted to the given event.

This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event semantics and does not listen to the 'error' event.

import { once, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

process.nextTick(() => {
  ee.emit('myevent', 42);
});

const [value] = await once(ee, 'myevent');
console.log(value);

const err = new Error('kaboom');
process.nextTick(() => {
  ee.emit('error', err);
});

try {
  await once(ee, 'myevent');
} catch (err) {
  console.error('error happened', err);
}

The special handling of the 'error' event is only used when events.once() is used to wait for another event. If events.once() is used to wait for the ‘error' event itself, then it is treated as any other kind of event without special handling:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();

once(ee, 'error')
  .then(([err]) => console.log('ok', err.message))
  .catch((err) => console.error('error', err.message));

ee.emit('error', new Error('boom'));

// Prints: ok boom

An AbortSignal can be used to cancel waiting for the event:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();
const ac = new AbortController();

async function foo(emitter, event, signal) {
  try {
    await once(emitter, event, { signal });
    console.log('event emitted!');
  } catch (error) {
    if (error.name === 'AbortError') {
      console.error('Waiting for the event was canceled!');
    } else {
      console.error('There was an error', error.message);
    }
  }
}

foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!

Parameters

Parameter	Type
emitter	EventEmitter
eventName	string | symbol
options?	StaticEventEmitterOptions

Returns

Promise<any[]>

Since

v11.13.0, v10.16.0

Inherited from

EventEmitter.once

Call Signature

static once(
   emitter: EventTarget,
   eventName: string,
options?: StaticEventEmitterOptions): Promise<any[]>;

Defined in: node_modules/@types/node/events.d.ts:189

Creates a Promise that is fulfilled when the EventEmitter emits the given event or that is rejected if the EventEmitter emits 'error' while waiting. The Promise will resolve with an array of all the arguments emitted to the given event.

This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event semantics and does not listen to the 'error' event.

import { once, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

process.nextTick(() => {
  ee.emit('myevent', 42);
});

const [value] = await once(ee, 'myevent');
console.log(value);

const err = new Error('kaboom');
process.nextTick(() => {
  ee.emit('error', err);
});

try {
  await once(ee, 'myevent');
} catch (err) {
  console.error('error happened', err);
}

The special handling of the 'error' event is only used when events.once() is used to wait for another event. If events.once() is used to wait for the ‘error' event itself, then it is treated as any other kind of event without special handling:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();

once(ee, 'error')
  .then(([err]) => console.log('ok', err.message))
  .catch((err) => console.error('error', err.message));

ee.emit('error', new Error('boom'));

// Prints: ok boom

An AbortSignal can be used to cancel waiting for the event:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();
const ac = new AbortController();

async function foo(emitter, event, signal) {
  try {
    await once(emitter, event, { signal });
    console.log('event emitted!');
  } catch (error) {
    if (error.name === 'AbortError') {
      console.error('Waiting for the event was canceled!');
    } else {
      console.error('There was an error', error.message);
    }
  }
}

foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!

Parameters

Parameter	Type
emitter	EventTarget
eventName	string
options?	StaticEventEmitterOptions

Returns

Promise<any[]>

Since

v11.13.0, v10.16.0

Inherited from

EventEmitter.once

---

setMaxListeners()

static setMaxListeners(n?: number, ...eventTargets: (EventEmitter<DefaultEventMap> | EventTarget)[]): void;

Defined in: node_modules/@types/node/events.d.ts:369

import { setMaxListeners, EventEmitter } from 'node:events';

const target = new EventTarget();
const emitter = new EventEmitter();

setMaxListeners(5, target, emitter);

Parameters

Parameter	Type	Description
n?	number	A non-negative number. The maximum number of listeners per EventTarget event.
…eventTargets?	(EventEmitter<DefaultEventMap> | EventTarget)[]	Zero or more {EventTarget} or {EventEmitter} instances. If none are specified, n is set as the default max for all newly created {EventTarget} and {EventEmitter} objects.

Returns

void

Since

v15.4.0

Inherited from

EventEmitter.setMaxListeners