A walkthrough of how I built a node.js application, showing modules, extracted code and examples.

1. A NODE.JS APPLICATION
Robbie Clutton

2. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

3. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

4. CONCEPTS
• CommonJS (http://www.commonjs.org)
• Lint (http://www.javascriptlint.com/)

5. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

6. TOOLBOX
• nodejs - server side javascript vm (http://nodejs.org/)
• connect - middleware (http://github.com/senchalabs/connect)
• express - sinatra like routing (http://expressjs.com/)
• ndistro - dependencies (http://github.com/visionmedia/ndistro)
• ejs - view templates (http://github.com/visionmedia/ejs)
• mongoose- mongodb driver(http://github.com/LearnBoost/
mongoose)
• log4js - logging (http://github.com/csausdev/log4js-node)

7. CONNECT
• Middleware framework
• Allowsfilters to be added to HTTP processing (e.g. logging,
authentication)

8. CONNECT EXAMPLE
var server = Connect.createServer(
Connect.logger(),
function(req, res) {
res.writeHead(200, {
'Content-Type': 'text/plain'
});
res.end('Hello World');
}
);

9. EXPRESS JS
var app = require('express').createServer();
app.get('/', function(req, res){
res.send('hello world');
});
app.listen(3000);

10. EJS
res.render('show_username.ejs', {
locals:{user:user}
});
<% if (user) { %>
<h2><%= user.name %></h2>
<% } %>

11. MONGOOSE
var mongoose = require('../modules/mongoose/mongoose').Mongoose;
var db = mongoose.connect('mongodb://localhost/tapas');
mongoose.model('User', {
'properties': ['username', 'password', 'first', 'last', ...],
'indexes': ['first', 'last', [{'username':1},{unique: true}]],
'methods': {
save: function(fn){
this.updated_at = new Date();
this.__super__(fn);
}
}
});
module.exports = db.model('User');

12. LOG4JS
var log4js = require('log4js');
log4js.addAppender(log4js.fileAppender('log/app.log'), 'controller.client');
var logger = log4js.getLogger('controller.client');
logger.setLevel('DEBUG');
logger.debug(‘hello, world’);
[2010-09-28 19:50:24.816] [DEBUG] controller.user - hello, world

13. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

14. EXTRACTED MODULES
• node-daemon - a module for start-stop functionality without
the need for init.d scripts (http://github.com/theteam/node-
daemon)
• node-properties - a module for reading JSON property files
using override pattern borrowed from Ant (http://github.com/
theteam/node-properties)
• tapas-models
- a module for common data entities with
mongodb wrappers - (http://github.com/theteam/tapas-
models)

15. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

16. NDISTRO
• Bash script that creates distributions from github for node
binaries and modules
• Because it’s bash, it can easily be extended
• Hash simple syntax
• If
modules are configured nicely, will symlink modules onto
node execution path

17. NDISTRO EXAMPLE
node 0.2.0
module senchalabs connect
module visionmedia express 1.0.0beta2
module visionmedia ejs
./bin/node
./modules/senchalabs/connect
./modules/visionmedia/express
./modules/visionmedia/ejs
./lib/node/connect
./lib/node/express
./lib/node/ejs

18. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

19. DESIGN DECISIONS
• Included everything from:
• directory structure
• bootstrap and running the application

20. NOT ANOTHER NODE.JS
HELLO WORLD
• An application built to run on node.js
• Concepts
• Modules used for the application
• Modules extracted from the application
• How dependencies of modules was managed
• Design decisions made during development
• Hosting

21. HOSTING
• Joyent (https://no.de/)
• Heroku (http://heroku.com/)