sockjs-client

What is sockjs-client?

The sockjs-client npm package provides a browser JavaScript library that provides a WebSocket-like object that offers a consistent, cross-browser interface for real-time, bi-directional communication between the client and the server. It falls back to a variety of browser-specific transport protocols if WebSockets are not available.

What are sockjs-client's main functionalities?

Establishing a connection to a SockJS server

This code sample demonstrates how to establish a connection to a SockJS server. It creates a new SockJS client instance, sets up event listeners for 'open', 'message', and 'close' events, and logs information to the console when these events occur.

var sock = new SockJS('http://mydomain.com/my_prefix');
sock.onopen = function() {
  console.log('open');
};
sock.onmessage = function(e) {
  console.log('message', e.data);
};
sock.onclose = function() {
  console.log('close');
};

Sending messages to the server

This code sample shows how to send a message to the server using the SockJS client. It sends a JSON stringified object as the message content.

sock.send(JSON.stringify({message: 'Hello, server!'}));

Receiving messages from the server

This code sample illustrates how to receive messages from the server. It sets up an event listener for the 'message' event and logs the received message to the console after parsing the JSON data.

sock.onmessage = function(e) {
  var message = JSON.parse(e.data);
  console.log('Received message:', message);
};

Closing the connection

This code sample demonstrates how to close the connection to the server using the SockJS client.

sock.close();

Other packages similar to sockjs-client

websocket

The 'websocket' npm package provides client and server implementations of the WebSocket protocol. It is more focused on providing a low-level WebSocket API and does not include the same level of fallback options for older browsers or environments that do not support WebSockets, unlike sockjs-client which provides a variety of fallbacks.

socket.io-client

The 'socket.io-client' package is the client-side library of Socket.IO, which enables real-time bidirectional event-based communication. It is similar to sockjs-client in providing fallbacks for WebSockets, but it also offers additional features like auto-reconnection, event broadcasting, and rooms for organizing clients, which sockjs-client does not provide out of the box.

engine.io-client

The 'engine.io-client' is the client component of Engine.IO, the core of Socket.IO. It is responsible for handling the connection transport, including long-polling and other fallback mechanisms. It is similar to sockjs-client in terms of providing reliable connections in diverse environments but is typically used as part of the larger Socket.IO framework.

README

SockJS Client Node

Node client for SockJS. Currently, only the XHR Streaming transport is supported.

Usage

var sjsc = require('sockjs-client');
var client = sjsc.create("http://localhost/sjsServer");
client.on('connection', function () { // connection is established });
client.on('data', function (msg) { // received some data });
client.on('error', function (e) { // something went wrong });
client.write("Have some text you mighty SockJS server!");