firebase-js-sdk/docs-devsite/remote-config.configupdateobserver.md

Project: /docs/reference/js/_project.yaml
Book: /docs/reference/_book.yaml
page_type: reference

{% comment %}
DO NOT EDIT THIS FILE!
This is generated by the JS SDK team, and any local changes will be
overwritten. Changes should be made in the source code at
https://github.com/firebase/firebase-js-sdk
{% endcomment %}

# ConfigUpdateObserver interface
Observer interface for receiving real-time Remote Config update notifications.

NOTE: Although an `complete` callback can be provided, it will never be called because the ConfigUpdate stream is never-ending.

<b>Signature:</b>

```typescript
export interface ConfigUpdateObserver 
```

## Properties

|  Property | Type | Description |
|  --- | --- | --- |
|  [complete](./remote-config.configupdateobserver.md#configupdateobservercomplete) | () =&gt; void | Called when the stream is gracefully terminated. |
|  [error](./remote-config.configupdateobserver.md#configupdateobservererror) | (error: [FirebaseError](./util.firebaseerror.md#firebaseerror_class)<!-- -->) =&gt; void | Called if an error occurs during the stream. |
|  [next](./remote-config.configupdateobserver.md#configupdateobservernext) | (configUpdate: [ConfigUpdate](./remote-config.configupdate.md#configupdate_interface)<!-- -->) =&gt; void | Called when a new ConfigUpdate is available. |

## ConfigUpdateObserver.complete

Called when the stream is gracefully terminated.

<b>Signature:</b>

```typescript
complete: () => void;
```

## ConfigUpdateObserver.error

Called if an error occurs during the stream.

<b>Signature:</b>

```typescript
error: (error: FirebaseError) => void;
```

## ConfigUpdateObserver.next

Called when a new ConfigUpdate is available.

<b>Signature:</b>

```typescript
next: (configUpdate: ConfigUpdate) => void;
```