Class: Client

Main class for working with Yurba API

The Client class is the main entry point for interacting with the Yurba.one platform. It provides methods for sending messages, registering commands, handling events, and managing bot functionality.

Examples

typescript

import { Client } from 'yurba.js';

const client = new Client('your-token-here');

client.registerCommand('hello', { name: 'string' }, (message, args) => {
  message.reply(`Hello, ${args.name}!`);
});

client.on('ready', () => {
  console.log('Bot is ready!');
});

client.init();

typescript

const client = new Client('token', {
  prefix: '!',
  maxReconnectAttempts: 10
});

Extends

EventEmitter

Constructors

Constructor

new Client(token, options): Client

Creates a new Yurba client

Parameters

token

string

Authorization token from Yurba.one (must start with 'y.' and be at least 34 characters)

options

ClientOptions = {}

Client configuration options

Returns

Client

Throws

When token format is invalid

Example

typescript

const client = new Client('y.your-token-here', {
  prefix: '!',
  maxReconnectAttempts: 10,
  intents: ['dialogs']
});

Overrides

EventEmitter.constructor

Properties

userClient

userClient: UserClientManager

users

users: UserManager

captureRejections

static captureRejections: boolean

Value: boolean

Change the default captureRejections option on all new EventEmitter objects.

Since

v13.4.0, v12.16.0

Inherited from

EventEmitter.captureRejections

captureRejectionSymbol

readonly static captureRejectionSymbol: typeof captureRejectionSymbol

Value: Symbol.for('nodejs.rejection')

See how to write a custom rejection handler.

Since

v13.4.0, v12.16.0

Inherited from

EventEmitter.captureRejectionSymbol

defaultMaxListeners

static defaultMaxListeners: number

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 change the default for allEventEmitter instances, the events.defaultMaxListeners property can be used. If this value is not a positive number, a RangeError is thrown.

Take caution when setting the events.defaultMaxListeners because the change affects all EventEmitter instances, including those created before the change is made. However, calling emitter.setMaxListeners(n) still has precedence over events.defaultMaxListeners.

This is not a hard limit. The EventEmitter instance will allow more listeners to be added but will output a trace warning to stderr indicating that a "possible EventEmitter memory leak" has been detected. For any single EventEmitter, the emitter.getMaxListeners() and emitter.setMaxListeners() methods can be used to temporarily avoid this warning:

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.setMaxListeners(emitter.getMaxListeners() + 1);
emitter.once('event', () => {
  // do stuff
  emitter.setMaxListeners(Math.max(emitter.getMaxListeners() - 1, 0));
});

The --trace-warnings command-line flag can be used to display the stack trace for such warnings.

The emitted warning can be inspected with process.on('warning') and will have the additional emitter, type, and count properties, referring to the event emitter instance, the event's name and the number of attached listeners, respectively. Its name property is set to 'MaxListenersExceededWarning'.

Since

v0.11.2

Inherited from

EventEmitter.defaultMaxListeners

errorMonitor

readonly static errorMonitor: typeof errorMonitor

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 listener using this symbol does not change the behavior once an 'error' event is emitted. Therefore, the process will still crash if no regular 'error' listener is installed.

Since

v13.6.0, v12.17.0

Inherited from

EventEmitter.errorMonitor

Accessors

dialogs

Get Signature

get dialogs(): undefined | Dialog[]

Getter for bot user dialogs

Returns

undefined | Dialog[]

Dialogs

user

Get Signature

get user(): null | User

Gets bot user data (synchronous)

Returns

null | User

User | null Bot user data or null if loading

Methods

[captureRejectionSymbol]()?

optional [captureRejectionSymbol]<K>(error, event, ...args): void

Type Parameters

K

K

Parameters

error

Error

event

string | symbol

args

...AnyRest

Returns

void

Inherited from

EventEmitter.[captureRejectionSymbol]

addListener()

addListener<K>(eventName, listener): this

Alias for emitter.on(eventName, listener).

Type Parameters

K

K

Parameters

eventName

string | symbol

listener

(...args) => void

Returns

this

Since

v0.1.26

Inherited from

EventEmitter.addListener

deleteMessage()

deleteMessage(ID): Promise<boolean>

Deletes a message by its ID

Parameters

ID

number

Message ID to delete

Returns

Promise<boolean>

Promise that resolves with boolean indicating success

emit()

emit(event, ...args): boolean

Internal

Emits the specified event with given arguments

Parameters

event

Event name or symbol

string | symbol

args

...any[]

Arguments to pass to event listeners

Returns

boolean

True if the event had listeners, false otherwise

Example

 client.emit('customEvent', { foo: 'bar' });

Overrides

EventEmitter.emit

eventNames()

eventNames(): (string | symbol)[]

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

getCommands()

getCommands(): string[]

Returns list of registered commands

Returns

string[]

Array of command names

Example

const commands = client.getCommands();
console.log('Registered commands:', commands);
// Result: Registered commands: [ 'info', 'help' ]

getMaxListeners()

getMaxListeners(): number

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

getMiddlewares()

getMiddlewares(): MiddlewareConfig[]

Gets a list of all middleware

Returns

MiddlewareConfig[]

Array of middleware configurations

getPhoto()

getPhoto(photoId): Promise<null | Photo>

Gets a photo from Yurba

Parameters

photoId

string

Photo ID to retrieve

Returns

Promise<null | Photo>

Promise that resolves with API response

getUser()

getUser(userTag): Promise<null | User>

Gets user information by tag

Parameters

userTag

string

User tag

Returns

Promise<null | User>

Promise that resolves with user data

init()

init(): Promise<void>

Initializes the client

Returns

Promise<void>

Promise that resolves after successful initialization

listenerCount()

listenerCount<K>(eventName, listener?): number

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

K

K

Parameters

eventName

The name of the event being listened for

string | symbol

listener?

Function

The event handler function

Returns

number

Since

v3.2.0

Inherited from

EventEmitter.listenerCount

listeners()

listeners<K>(eventName): Function[]

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

K

K

Parameters

eventName

string | symbol

Returns

Function[]

Since

v0.1.26

Inherited from

EventEmitter.listeners

off()

off(event, listener): this

Removes a listener for the specified event

Parameters

event

Event name or symbol

string | symbol

listener

(...args) => void

Callback function to remove

Returns

this

Client instance

Example

const handler = (msg) => {};
client.on('message', handler);
client.off('message', handler);

Overrides

EventEmitter.off

on()

on(event, listener): this

Adds a listener for the specified event

Parameters

event

Event name or symbol

string | symbol

listener

(...args) => void

Callback function

Returns

this

Client instance

Example

client.on('message', (msg) => {
  console.log('Received message:', msg);
});

Overrides

EventEmitter.on

once()

once(event, listener): this

Adds a one-time listener for the specified event The listener is invoked only the next time the event is triggered, then removed

Parameters

event

Event name or symbol

string | symbol

listener

(...args) => void

Callback function

Returns

this

Client instance

Example

client.once('ready', () => {
  console.log('Bot is ready!');
});

Overrides

EventEmitter.once

prependListener()

prependListener<K>(eventName, listener): this

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

K

K

Parameters

eventName

The name of the event.

string | symbol

listener

(...args) => void

The callback function

Returns

this

Since

v6.0.0

Inherited from

EventEmitter.prependListener

prependOnceListener()

prependOnceListener<K>(eventName, listener): this

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

K

K

Parameters

eventName

The name of the event.

string | symbol

listener

(...args) => void

The callback function

Returns

this

Since

v6.0.0

Inherited from

EventEmitter.prependOnceListener

rawListeners()

rawListeners<K>(eventName): Function[]

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

K

K

Parameters

eventName

string | symbol

Returns

Function[]

Since

v9.4.0

Inherited from

EventEmitter.rawListeners

registerCommand()

registerCommand(command, argsSchema, handler): void

Registers a new command

Parameters

command

string

Command name

argsSchema

CommandArgsSchema

Command arguments schema

handler

CommandHandler

Command handler

Returns

void

Examples

client.registerCommand('hello', { name: 'string' }, (message, args) => {
  console.log(`Hello, ${args.name}!`);
});

client.registerCommand('add', { a: 'int', b: 'int' }, (message, args) => {
  const sum = args.a + args.b;
  message.reply(`The sum is ${sum}`);
});

removeAllListeners()

removeAllListeners(event?): this

Removes all listeners or those specified for an event

Parameters

event?

Event name or symbol (optional)

string | symbol

Returns

this

Client instance

Example

client.removeAllListeners('message');

Overrides

EventEmitter.removeAllListeners

removeListener()

removeListener(event, listener): this

Removes a specific listener from an event Alias for off()

Parameters

event

Event name or symbol

string | symbol

listener

(...args) => void

Callback function to remove

Returns

this

Client instance

Overrides

EventEmitter.removeListener

removeMiddleware()

removeMiddleware(name): boolean

Removes middleware by name

Parameters

name

string

Middleware name

Returns

boolean

Boolean indicating whether the middleware was removed

sendMessage()

sendMessage(dialogId, payload): Promise<Message>

Send message to dialog

Parameters

dialogId

number

Dialog identifier

payload

SendMessagePayload

SendMessagePayload Message data

Returns

Promise<Message>

Message Sent message

Example

javascript

// Text message
await client.sendMessage(123, { text: "Hello!" });

// With photos and reply
await client.sendMessage(123, {
  text: "Check this",
  photos_list: [-1112],
  replyTo: 48561
});

// With attachments
await client.sendMessage(123, {
  text: "Media",
  attachments: [
    { Type: "video", Item: 28 },
    { Type: "track", Item: 6422 },
    { Type: "file", Item: 684 },
    { Type: "post", Item: 3201 }
  ]
});

// Edit message
await client.sendMessage(123, {
  text: "Updated",
  edit: 12345
});

setMaxListeners()

setMaxListeners(n): this

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

n

number

Returns

this

Since

v0.3.5

Inherited from

EventEmitter.setMaxListeners

typing()

typing(dialogId): void

Shows typing indicator in dialog

Parameters

dialogId

number

Dialog ID

Returns

void

use()

use(middleware, config?): void

Adds a middleware function to execute for each incoming message

Parameters

middleware

MiddlewareFunction

Middleware function

config?

MiddlewareConfig

Middleware configuration

Returns

void

waitFor()

waitFor<T>(event, check, options): Promise<any>

Waits for a specific event and resolves when the check function returns true

Type Parameters

T

T extends any[] = any[]

Type of arguments passed to the event

Parameters

event

string

Event name to listen for

check

(...args) => boolean

Function that receives event arguments and returns boolean, indicating whether the desired condition is met

options

Additional parameters:

timeout: Maximum time to wait for the event in milliseconds. Default is 60000.
multiple: If true, resolves with all arguments as an array; otherwise resolves with the first argument or full array of arguments if there are multiple.
signal: AbortSignal to cancel the wait operation.

multiple?

boolean

signal?

AbortSignal

timeout?

number

Returns

Promise<any>

Promise that resolves with event arguments when condition is met, or rejects if timeout is reached or operation is cancelled.

Examples

1
// Wait for a message with text "Hello"
await client.waitFor('message', msg => msg.Text === 'Hello', { timeout: 5000 });

2
// Wait for user event and get all arguments
const [arg1, arg2] = await client.waitFor('customEvent', () => true, { multiple: true });

addAbortListener()

static addAbortListener(signal, resource): Disposable

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

signal

AbortSignal

resource

(event) => void

Returns

Disposable

Disposable that removes the abort listener.

Since

v20.5.0

Inherited from

EventEmitter.addAbortListener

getEventListeners()

static getEventListeners(emitter, name): Function[]

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

emitter

EventTarget | EventEmitter<DefaultEventMap>

name

string | symbol

Returns

Function[]

Since

v15.2.0, v14.17.0

Inherited from

EventEmitter.getEventListeners

getMaxListeners()

static getMaxListeners(emitter): number

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

emitter

EventTarget | EventEmitter<DefaultEventMap>

Returns

number

Since

v19.9.0

Inherited from

EventEmitter.getMaxListeners

listenerCount()

static listenerCount(emitter, eventName): number

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

Parameters

emitter

EventEmitter

The emitter to query

eventName

The event name

string | symbol

Returns

number

Since

v0.9.12

Deprecated

Since v3.2.0 - Use listenerCount instead.

Inherited from

EventEmitter.listenerCount

on()

Call Signature

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

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

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, eventName, options?): AsyncIterator<any[]>

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

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

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, eventName, options?): Promise<any[]>

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

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, eventName, options?): Promise<any[]>

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);
}

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

emitter

EventTarget

eventName

string

options?

StaticEventEmitterOptions

Returns

Promise<any[]>

Since

v11.13.0, v10.16.0

Inherited from

EventEmitter.once

setMaxListeners()

static setMaxListeners(n?, ...eventTargets?): void

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

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

setMaxListeners(5, target, emitter);

Parameters

n?

number

A non-negative number. The maximum number of listeners per EventTarget event.

eventTargets?

...(EventTarget | EventEmitter<DefaultEventMap>)[]

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

Client

Other

Class: Client ​

Examples ​

Extends ​

Constructors ​

Constructor ​

Parameters ​

token ​

options ​

Returns ​

Throws ​

Example ​

Overrides ​

Properties ​

userClient ​

users ​

captureRejections ​

Since ​

Inherited from ​

captureRejectionSymbol ​

Since ​

Inherited from ​

defaultMaxListeners ​

Since ​

Inherited from ​

errorMonitor ​

Since ​

Inherited from ​

Accessors ​

dialogs ​

Get Signature ​

Returns ​

user ​

Get Signature ​

Returns ​

Methods ​

[captureRejectionSymbol]()? ​

Type Parameters ​

K ​

Parameters ​

error ​

event ​

args ​

Returns ​

Inherited from ​

addListener() ​

Type Parameters ​

K ​

Parameters ​

eventName ​

listener ​

Returns ​

Since ​

Inherited from ​

deleteMessage() ​

Parameters ​

ID ​

Returns ​

emit() ​

Parameters ​

event ​

args ​

Returns ​

Example ​

Overrides ​

eventNames() ​

Returns ​

Since ​

Inherited from ​

getCommands() ​

Returns ​

Example ​

getMaxListeners() ​

Returns ​

Since ​

Inherited from ​

getMiddlewares() ​

Returns ​

getPhoto() ​

Class: Client

Examples

Extends

Constructors

Constructor

Parameters

token

options

Returns

Throws

Example

Overrides

Properties

userClient

users

captureRejections

Since

Inherited from

captureRejectionSymbol

Since

Inherited from

defaultMaxListeners

Since

Inherited from

errorMonitor

Since

Inherited from

Accessors

dialogs

Get Signature

Returns

user

Get Signature

Returns

Methods

[captureRejectionSymbol]()?

Type Parameters

K

Parameters

error

event

args

Returns

Inherited from

addListener()

Type Parameters

K

Parameters

eventName

listener

Returns

Since

Inherited from

deleteMessage()

Parameters

ID

Returns

emit()

Parameters

event

args

Returns

Example

Overrides

eventNames()

Returns

Since

Inherited from

getCommands()

Returns

Example

getMaxListeners()

Returns

Since

Inherited from

getMiddlewares()

Returns

getPhoto()

Parameters

photoId