# Azure Communication Signaling client library for JavaScript

The Azure Communication Signaling client library lets developers add real-time notifications for receiving new/update/delete chat message events, typing indicator event, read receipt event, and chat thread events.

Read more about Azure Communication Services [here](https://docs.microsoft.com/azure/communication-services/overview)

## Getting started

## Prerequisites

- An [Azure subscription][azure_sub].
- An existing Communication Services resource. If you need to create the resource, you can use the [Azure Portal][azure_portal], the [Azure PowerShell][azure_powershell], or the [Azure CLI][azure_cli].
- [Node.js](https://nodejs.org)

### Installing

```bash
npm install @azure/communication-signaling
```

### Browser support

#### JavaScript Bundle

This client library is only supported in the browser. To use this client library, first you need to use a bundler. For details on how to do this, please refer to our [bundling documentation](https://aka.ms/AzureSDKBundling).

## Key concepts

### SignalingClient

`SignalingClient` is the primary interface for developers using this client library. It provides methods to enable/disable real-time notifications and register listeners for different events.

## Examples

### Initialize SignalingClient

Use user access token and Azure logger to initialize signaling client.

```JavaScript
import { CommunicationSignalingClient } from '@azure/communication-signaling';
import { AzureCommunicationTokenCredential } from "@azure/communication-common";
import { createClientLogger } from "@azure/logger";

let userAccessToken = '<USER_ACCESS_TOKEN>';
let tokenCredential = new AzureCommunicationTokenCredential(userAccessToken);
let logger = createClientLogger("communication-signaling");
let signalingClient = new CommunicationSignalingClient(tokenCredential, logger);

```

### Enable real-time notifications

```JavaScript
signalingClient.start();

```

### Disable real-time notifications

```JavaScript
signalingClient.stop();

```

### Register listener to events

With real-time signaling, you can subscribe to listen for new incoming events and call your own business logic accordingly.

```JavaScript

// register listener to new incoming message event
signalingClient.on("chatMessageReceived", (payload) => {
    console.log("Notification chatMessageReceived!");
    // your code here
});

// register listener to typing indicator event
signalingClient.on("typingIndicatorReceived", (payload) => {
    console.log("Notification typingIndicatorReceived!");
    // your code here
});

// register listener to thread deleted event
signalingClient.on("chatThreadDeleted", (payload) => {
    console.log("Notification chatThreadDeleted!");
    // your code here
});

```

[azure_cli]: https://docs.microsoft.com/cli/azure
[azure_sub]: https://azure.microsoft.com/free/
[azure_portal]: https://portal.azure.com
[azure_powershell]: https://docs.microsoft.com/powershell/module/az.communication/new-azcommunicationservice