Book Image

Learning Node.js for .NET Developers

Book Image

Learning Node.js for .NET Developers

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 (21 chapters)
Learning Node.js for .NET Developers
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Organizing Socket.IO applications


Now that we have a chat lobby on the index page of our application, it's a bit odd that users have to reload the page (and lose the chat history) to find out about new games. We can use Socket.IO to update these as well.

Exposing real-time updates to the model

First, we'll need our games service itself to expose events for when games are added or removed. Here we use the Mongoose-provided post method to hook into persistence operations on games as given here src/services/games.js:

'use strict';

const EventEmitter = require('events');
const emitter = new EventEmitter();

module.exports = (mongoose) => {
    let Game = mongoose.models['Game'];

    if (!Game) {
        let Schema = mongoose.Schema;
        let gameSchema = new Schema({
            word: String,
            setBy: String
        });

        ...
        
        gameSchema.post('save', game =>
            emitter.emit('gameSaved', game));
        gameSchema.post('remove', game =>
  ...