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

# EventEmitterable

An **EventEmitterable** behaves similar to an EventEmitter except provides async access to its methods.

An EventEmitter implements the observer pattern.

## Extended by

* [`Provider`](/sdk/content/interfaces/Provider)

## Type parameters

| Type parameter |
| :------------- |
| `T`            |

## Methods

### addListener()

```ts theme={null}
addListener(
   event, 
   listener, 
zone?): Promise<EventEmitterable<T>>
```

Alias for [**on**](/sdk/content/interfaces/EventEmitterable#on).

#### Parameters

| Parameter  | Type                                             |
| :--------- | :----------------------------------------------- |
| `event`    | `T`                                              |
| `listener` | [`Listener`](/sdk/content/type-aliases/Listener) |
| `zone`?    | [`Zone`](/sdk/content/enumerations/Zone)         |

#### Returns

`Promise`\<[`EventEmitterable`](/sdk/content/interfaces/EventEmitterable)\<`T`>>

#### Source

[utils/events.ts:61](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L61)

***

### emit()

```ts theme={null}
emit(
   event, 
   zone?, ...
args?): Promise<boolean>
```

Triggers each listener for `event` with the `args`.

#### Parameters

| Parameter  | Type                                     |
| :--------- | :--------------------------------------- |
| `event`    | `T`                                      |
| `zone`?    | [`Zone`](/sdk/content/enumerations/Zone) |
| ...`args`? | `any`\[]                                 |

#### Returns

`Promise`\<`boolean`>

#### Source

[utils/events.ts:36](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L36)

***

### listenerCount()

```ts theme={null}
listenerCount(event?): Promise<number>
```

Resolves to the number of listeners for `event`.

#### Parameters

| Parameter | Type |
| :-------- | :--- |
| `event`?  | `T`  |

#### Returns

`Promise`\<`number`>

#### Source

[utils/events.ts:41](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L41)

***

### listeners()

```ts theme={null}
listeners(event?): Promise<Listener[]>
```

Resolves to the listeners for `event`.

#### Parameters

| Parameter | Type |
| :-------- | :--- |
| `event`?  | `T`  |

#### Returns

`Promise`\<[`Listener`](/sdk/content/type-aliases/Listener)\[]>

#### Source

[utils/events.ts:46](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L46)

***

### off()

```ts theme={null}
off(
   event, 
   listener?, 
zone?): Promise<EventEmitterable<T>>
```

Unregister the `listener` for `event`. If `listener` is unspecified, all listeners are unregistered.

#### Parameters

| Parameter   | Type                                             |
| :---------- | :----------------------------------------------- |
| `event`     | `T`                                              |
| `listener`? | [`Listener`](/sdk/content/type-aliases/Listener) |
| `zone`?     | [`Zone`](/sdk/content/enumerations/Zone)         |

#### Returns

`Promise`\<[`EventEmitterable`](/sdk/content/interfaces/EventEmitterable)\<`T`>>

#### Source

[utils/events.ts:51](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L51)

***

### on()

```ts theme={null}
on(
   event, 
   listener, 
zone?): Promise<EventEmitterable<T>>
```

Registers a `listener` that is called whenever the `event` occurs until unregistered.

#### Parameters

| Parameter  | Type                                             |
| :--------- | :----------------------------------------------- |
| `event`    | `T`                                              |
| `listener` | [`Listener`](/sdk/content/type-aliases/Listener) |
| `zone`?    | [`Zone`](/sdk/content/enumerations/Zone)         |

#### Returns

`Promise`\<[`EventEmitterable`](/sdk/content/interfaces/EventEmitterable)\<`T`>>

#### Source

[utils/events.ts:26](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L26)

***

### once()

```ts theme={null}
once(
   event, 
   listener, 
zone?): Promise<EventEmitterable<T>>
```

Registers a `listener` that is called the next time `event` occurs.

#### Parameters

| Parameter  | Type                                             |
| :--------- | :----------------------------------------------- |
| `event`    | `T`                                              |
| `listener` | [`Listener`](/sdk/content/type-aliases/Listener) |
| `zone`?    | [`Zone`](/sdk/content/enumerations/Zone)         |

#### Returns

`Promise`\<[`EventEmitterable`](/sdk/content/interfaces/EventEmitterable)\<`T`>>

#### Source

[utils/events.ts:31](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L31)

***

### removeAllListeners()

```ts theme={null}
removeAllListeners(event?): Promise<EventEmitterable<T>>
```

Unregister all listeners for `event`.

#### Parameters

| Parameter | Type |
| :-------- | :--- |
| `event`?  | `T`  |

#### Returns

`Promise`\<[`EventEmitterable`](/sdk/content/interfaces/EventEmitterable)\<`T`>>

#### Source

[utils/events.ts:56](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L56)

***

### removeListener()

```ts theme={null}
removeListener(
   event, 
   listener, 
zone?): Promise<EventEmitterable<T>>
```

Alias for [**off**](/sdk/content/interfaces/EventEmitterable#off).

#### Parameters

| Parameter  | Type                                             |
| :--------- | :----------------------------------------------- |
| `event`    | `T`                                              |
| `listener` | [`Listener`](/sdk/content/type-aliases/Listener) |
| `zone`?    | [`Zone`](/sdk/content/enumerations/Zone)         |

#### Returns

`Promise`\<[`EventEmitterable`](/sdk/content/interfaces/EventEmitterable)\<`T`>>

#### Source

[utils/events.ts:66](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/utils/events.ts#L66)