WebSocket

The WebSocket API provides access to the Session object for the management of bi-directional communication based on the WebSocket specification. WebSockets enable real-time, full-duplex communication between a client (such as a web browser) and a server over a single, long-lived connection.

Overview

WebSocket is a communication protocol that provides a full-duplex, persistent connection between a client and a server, allowing them to exchange messages in real-time. The WebSocket API offers developers a way to interact with WebSocket sessions, handle events, and send/receive messages efficiently.

Key Features

• WebSocket Session Management: The API provides functionalities to manage WebSocket sessions, including opening, closing, and handling events.
• Message Exchange: Developers can send and receive messages over WebSocket connections, enabling real-time communication between clients and servers.
• Event Handling: The API supports event-driven programming, allowing developers to define callback functions to handle WebSocket events such as connection open, close, error, and message reception.
• Protocol Support: WebSocket API adheres to the WebSocket protocol specification, ensuring compatibility with WebSocket servers and clients.

Example Usage

Client

import { websockets } from "sdk/net"

const uri = "ws://echo.websocket.org:80/";
const handler = "my-project/ws-handler"

function initialize() {
    console.log("Connect to: " + uri);
    let websocket = websockets.createWebsocket(uri, handler);
    websocket.send("hello");
}

initialize();

websockets.getClientByHandler(handler).close();

Server

For example: my-endpoint.websocket is using the same handler from above

{
  "handler": "my-project/ws-handler",
  "endpoint":"my-endpoint",
  "description":"My Websocket"
}

then you can call from a browser:

let ws = new WebSocket("ws://localhost:8080/websockets/v4/service/my-endpoint");
ws.send('hello');

Functions

---

Function	Description	Returns
createWebsocket(uri, handler, engine)	Creates a WebsocketClient by URI, handler and engine type	WebsocketClient
getClients()	Returns the list of the created WebsocketClients	list of WebsocketClient metadata
getClient(id)	Returns the client by its id, if exists or null otherwise	WebsocketClient
getClientByHandler(handler)	Returns the client by its handler, if exists or null otherwise	WebsocketClient
getMessage()	Returns the message in context of OnMessage handler	string
getError()	Returns the error in context of OnError handler	string
getMethod()	Returns the method type in context of the handler	onopen, onmessage, onerror, onclose
isOnOpen()	Returns true in context of OnOpen handler	boolean
isOnMessage()	Returns true in context of OnMessage handler	boolean
isOnError()	Returns true in context of OnError handler	boolean
isOnClose()	Returns true in context of OnClose handler	boolean

Objects

---

WebsocketClient

Function	Description	Returns
send(message)	Sends a text message via the Websocket connection	-
close()	Closes the Websocket connection	-