Express Ws

Express with Websockets

Consider this as a drop-in replacement for ExpressJS with additional functionality to handle Websockets in familiar express-middelware style.

Installation

$ npm install @parthar/express-ws --save # the package

Usage

var expressWs = require("@parthar/express-ws");
var express = require("express");

// use like normal express-apps
var appWs = expressWs();
appWs.get("/hello", function (req, res, next) {
    res.send("hello world");
});

// mix both kinds of apps
var app = express();
app.get("/express", function (req, res, next) {
    res.send("plain express");
});
appWs.use(app);

// handle websockets upgrades in express-style
// use res.upgradeWs to accept the upgrade
app.get("/ws", function (req, res, next) {
    isAuthorized(req.headers.authorization, function (err, auth) {
        if (err) {
            return res.sendStatus(500);
        }
        if (!auth) {
            return res.sendStatus(401);
        }
        res.upgradeWs(function (ws) {
            ws.on("open", function () {
                // websocket opened
            });
            ws.on("close", function () {
                // websocket closed
            });
            ...
        });
    });
});

// listen on a port; similar to http.Server.listen()
appWs.listen(8080, callback);

// close when done; closes all opened websocket-connections
appWs.close(callback);

// http & ws servers are available as attributes: appWs.httpServer & appWs.wsServer
// can use these attributes for full functionality provided by respective entities

Notes

The Websocker-server is started in "noServer" mode. Also, "clientTracking" is enabled, which means that all websocket clients are available on the server via appWs.wsServer.clients attribute. Refer to Websockets for more details.