> ## Documentation Index
> Fetch the complete documentation index at: https://orderly.network/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Orderly network core.EventEmitter 1

[Orderly SDKs](/sdks/tech-doc/README) / [Modules](/sdks/tech-doc/modules) / [@orderly.network/core](/sdks/tech-doc/modules/orderly_network_core) / EventEmitter

# Class: EventEmitter\<EventTypes, Context>

[@orderly.network/core](/sdks/tech-doc/modules/orderly_network_core).EventEmitter

Minimal `EventEmitter` interface that is molded against the Node.js
`EventEmitter` interface.

## Type parameters

| Name         | Type                                                                                                                         |
| :----------- | :--------------------------------------------------------------------------------------------------------------------------- |
| `EventTypes` | extends [`ValidEventTypes`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#valideventtypes) = `string` \| `symbol` |
| `Context`    | extends `any` = `any`                                                                                                        |

## Table of contents

### Constructors

* [constructor](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#constructor)

### Properties

* [prefixed](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#prefixed)

### Methods

* [addListener](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#addlistener)
* [emit](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#emit)
* [eventNames](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#eventnames)
* [listenerCount](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#listenercount)
* [listeners](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#listeners)
* [off](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#off)
* [on](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#on)
* [once](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#once)
* [removeAllListeners](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#removealllisteners)
* [removeListener](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1#removelistener)

## Constructors

### constructor

• **new EventEmitter**\<`EventTypes`, `Context`>()

#### Type parameters

| Name         | Type                                                                                                                         |
| :----------- | :--------------------------------------------------------------------------------------------------------------------------- |
| `EventTypes` | extends [`ValidEventTypes`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#valideventtypes) = `string` \| `symbol` |
| `Context`    | extends `unknown` = `any`                                                                                                    |

## Properties

### prefixed

▪ `Static` **prefixed**: `string` | `boolean`

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:9

## Methods

### addListener

▸ **addListener**\<`T`>(`event`, `fn`, `context?`): [`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name       | Type                                                                                                          |
| :--------- | :------------------------------------------------------------------------------------------------------------ |
| `event`    | `T`                                                                                                           |
| `fn`       | [`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`> |
| `context?` | `Context`                                                                                                     |

#### Returns

[`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:45

***

### emit

▸ **emit**\<`T`>(`event`, `...args`): `boolean`

Calls each of the listeners registered for a given event.

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name      | Type                                                                                                                         |
| :-------- | :--------------------------------------------------------------------------------------------------------------------------- |
| `event`   | `T`                                                                                                                          |
| `...args` | `Parameters`\<[`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`>> |

#### Returns

`boolean`

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:32

***

### eventNames

▸ **eventNames**(): [`EventNames`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventnames)\<`EventTypes`>\[]

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

#### Returns

[`EventNames`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventnames)\<`EventTypes`>\[]

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:15

***

### listenerCount

▸ **listenerCount**(`event`): `number`

Return the number of listeners listening to a given event.

#### Parameters

| Name    | Type                                                                                               |
| :------ | :------------------------------------------------------------------------------------------------- |
| `event` | [`EventNames`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventnames)\<`EventTypes`> |

#### Returns

`number`

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:27

***

### listeners

▸ **listeners**\<`T`>(`event`): [`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`>\[]

Return the listeners registered for a given event.

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name    | Type |
| :------ | :--- |
| `event` | `T`  |

#### Returns

[`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`>\[]

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:20

***

### off

▸ **off**\<`T`>(`event`, `fn?`, `context?`, `once?`): [`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name       | Type                                                                                                          |
| :--------- | :------------------------------------------------------------------------------------------------------------ |
| `event`    | `T`                                                                                                           |
| `fn?`      | [`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`> |
| `context?` | `Context`                                                                                                     |
| `once?`    | `boolean`                                                                                                     |

#### Returns

[`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:69

***

### on

▸ **on**\<`T`>(`event`, `fn`, `context?`): [`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

Add a listener for a given event.

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name       | Type                                                                                                          |
| :--------- | :------------------------------------------------------------------------------------------------------------ |
| `event`    | `T`                                                                                                           |
| `fn`       | [`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`> |
| `context?` | `Context`                                                                                                     |

#### Returns

[`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:40

***

### once

▸ **once**\<`T`>(`event`, `fn`, `context?`): [`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

Add a one-time listener for a given event.

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name       | Type                                                                                                          |
| :--------- | :------------------------------------------------------------------------------------------------------------ |
| `event`    | `T`                                                                                                           |
| `fn`       | [`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`> |
| `context?` | `Context`                                                                                                     |

#### Returns

[`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:54

***

### removeAllListeners

▸ **removeAllListeners**(`event?`): [`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

Remove all listeners, or those of the specified event.

#### Parameters

| Name     | Type                                                                                               |
| :------- | :------------------------------------------------------------------------------------------------- |
| `event?` | [`EventNames`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventnames)\<`EventTypes`> |

#### Returns

[`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:79

***

### removeListener

▸ **removeListener**\<`T`>(`event`, `fn?`, `context?`, `once?`): [`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

Remove the listeners of a given event.

#### Type parameters

| Name | Type                         |
| :--- | :--------------------------- |
| `T`  | extends `string` \| `symbol` |

#### Parameters

| Name       | Type                                                                                                          |
| :--------- | :------------------------------------------------------------------------------------------------------------ |
| `event`    | `T`                                                                                                           |
| `fn?`      | [`EventListener`](/sdks/tech-doc/modules/orderly_network_core.EventEmitter#eventlistener)\<`EventTypes`, `T`> |
| `context?` | `Context`                                                                                                     |
| `once?`    | `boolean`                                                                                                     |

#### Returns

[`EventEmitter`](/sdks/tech-doc/classes/orderly_network_core.EventEmitter-1)\<`EventTypes`, `Context`>

#### Defined in

node\_modules/.pnpm/eventemitter3\@5.0.1/node\_modules/eventemitter3/index.d.ts:63