Book Image

Learning Node.js for .NET Developers

By : Cummings
Book Image

Learning Node.js for .NET Developers

By: Cummings

Overview of this book

Node.js is an open source, cross-platform runtime environment that allows you to use JavaScript to develop server-side web applications. This short guide will help you develop applications using JavaScript and Node.js, leverage your existing programming skills from .NET or Java, and make the most of these other platforms through understanding the Node.js programming model. You will learn how to build web applications and APIs in Node, discover packages in the Node.js ecosystem, test and deploy your Node.js code, and more. Finally, you will discover how to integrate Node.js and .NET code.
Table of Contents (16 chapters)
15
Index

Directing Socket.IO messages

Now that we have access to usernames, we can also announce the arrival of users in the lobby. We can do this by extending our Socket.IO connection event handler as given here src/realtime/chat.js:

'use strict';

module.exports = io => {

    io.on('connection', (socket) => {
        const username = socket.request.user.name;

        if(username) {
            socket.broadcast.emit('chatMessage', {
                username: username,
                message: 'has arrived',
                type: 'action'
            });
        }

        socket.on('chatMessage', (message) => {
            io.emit('chatMessage', {
                username: username,
                message: message
            });
        });
    });
 }

Here, we use socket.broadcast.emit, rather than io.emit, to send the event to all clients except for the current socket. Note that we also add extra data to the message...