## SubscriptionEmitter class

An `EventTarget` that emits events when new subscription notifications come in over WebSockets.

---

### Events emitted:

- `connect` - A new subscription is connected to the `SubscriptionManager` and `message` events for this subscription can be expected.
- `disconnect` - The specified subscription is no longer being monitored by the `SubscriptionManager`.
- `error` - An error has occurred.
- `message` - A message containing a notification `Bundle` has been received.
- `open` - The WebSocket has been opened.
- `close` - The WebSocket has been closed.
- `heartbeat` - A `heartbeat` message has been received.

**Signature:**

```typescript
export declare class SubscriptionEmitter extends TypedEventTarget<SubscriptionEventMap>
```

**Extends:** [TypedEventTarget](/content/docs/sdk/core.typedeventtarget) < [SubscriptionEventMap](/content/docs/sdk/core.subscriptioneventmap) >

## Constructors

| Constructor | Modifiers | Description |
| --- | --- | --- |
| [(constructor)(criteria)](/content/docs/sdk/core.subscriptionemitter._constructor_/index.html) |  | Constructs a new instance of the `SubscriptionEmitter` class |

## Methods

| Method | Modifiers | Description |
| --- | --- | --- |
| [getCriteria()](/content/docs/sdk/core.subscriptionemitter.getcriteria) |  |  |