1.
Node.js Workshop
Tom Hughes-Croucher
Chief Evangelist / Node Tech Lead
@sh1mmer
tom@joyent.com

2.
Overview
• Introduction
• Why Server-Side JavaScript?
• What is Node?
• Using Node
• Understanding Node
• Node Ecosystem
• Programming Style
• More Complex applications
• Deploying Node apps to the cloud

3.
Introduction
• Tom Hughes-Croucher
• Chief Evangelist at Joyent
• Node.js core contributor
• Author of "Up and Running with Node.js"

4.
Scalable Server-Side Code with JavaScript
Node Up and Running
Tom Hughes-Croucher

5.
Major update
this week

6.
Why Server-Side
JavaScript?

7.
JavaScript
programmers
3>2>1

8.
Massive Code base of
jQuery and other JS
libraries

9.
Laziness or “I’m sick
of writing stuff twice”
I could have said efficiency, but I think we all
secretly long to sit around in our underwear.

10.
Progressive
Enhancement is free*
Remember WWCD (What Would Crockford Do)
*close enough

11.
TL;DR:
SSJS is Awesome
Like a Unicorn riding a Narwhal

12.
If SSJS is so
awesome
why is it "new"?

13.
1. Professionalism

14.
“Yahoo!'s corporate
motto is: Don't be
eval().“

15.
2. JavaScript
Runtimes

16.
Runtimes
• V8 (Google), C++
• Spider Monkey (Mozilla), C++
• Rhino (Mozilla), Java

17.
V8
Spider
Monkey
JavaScript Performance

18.
8x
Sep 08! Mar 11!

19.
Anatomy of SSJS

20.
Node
{
!

21.
Runtime != Browser

22.
No DOM
(By default, anyway)

23.
Summary
• Benefits of SSJS
• Lots of JavaScript expertise
• Lots of web code in JS libraries
• Write once, run anywhere
• Progressive Enhancement
• Why SSJS happened now
• Professionalism in JavaScript
• New generation of JavaScript runtimes

24.
What is Node?

25.
Node
• JavaScript programming environment
• Uses V8 runtime
• Event Driven
• Non-blocking libraries
• Supports CommonJS module format
• Supports C/C++ based add-ons

26.
Woah! Overload.

27.
1. It's JavaScript

28.
See Above.

29.
2. It's Fast

30.
concurrency=300, Smaller is Better
400
300
response time (ms)
server
nginx
200 thin
tornado
node_buffer
100
24 26 28 210 212 214 216 218
response size (bytes)

31.
3. It's easy to extend

32.
'Modules' in JS
'Add-ons' in C

33.
4. Node is _not_ Rails/
Django/etc

34.
Node is bare-bone to
the metal

35.
However, the Node
community are making
Rails/Django/etc

36.
5. Node is young

37.
Stable is "stable"
Unstable moves fast

38.
Using Node

39.
Using Node
• Part 1. Installation
• Part 2. Basics
• Part 3. Getting stuck in

40.
Part 1. Installation

41.
Nave
a.k.a the easy way

42.
Enki:~ $ wget -q http://github.com/isaacs/nave/raw/
master/nave.sh
Enki:~ $ chmod 755 nave.sh
Enki:~ $ ./nave.sh install latest

43.
Nave
• Installs and versions Node
• Allows Node shells with specific versions
• Allows you to get 'latest' <-- Stable
• May add 'unstable' option in future

44.
Manual Installation

45.
Go to
http://nodejs.org/#download
and get the URL of the current
stable release

46.
Enki:~ $ wget -q http://nodejs.org/dist/node-
v0.4.10.tar.gz
Enki:~ $ tar xzf node-v0.4.10.tar.gz
Enki:~ $ cd node-v0.4.10
Enki:~/node-v0.4.10 $

47.
Local or system?

48.
Local

49.
Enki:~/node-v0.4.10 $ mkdir ~/local
Enki:~/node-v0.4.10 $ ./configure --prefix=~/local
Checking for program g++ or c++ : /usr/bin/g++
Checking for program cpp : /usr/bin/cpp
...
Checking for fdatasync(2) with c++ : no
'configure' finished successfully (3.466s)

50.
Enki:~/node-v0.4.10 $ make
Waf: Entering directory `/Users/sh1mmer/node-v0.4.10/build'
DEST_OS: darwin
DEST_CPU: x86
Parallel Jobs: 1
[ 1/69] cc: deps/libeio/eio.c -> build/default/deps/libeio/eio_1.o
/usr/bin/gcc -rdynamic -D_GNU_SOURCE -DHAVE_CONFIG_H=1
-DEV_MULTIPLICITY=0 -pthread -g -O3 -DHAVE_OPENSSL=1 -
DX_STACKSIZE=65536 -D_LARGEFILE_SOURCE -
D_FILE_OFFSET_BITS=64 -DHAVE_FDATASYNC=0 -
DPLATFORM="darwin" -DNDEBUG -Idefault/deps/libeio -I../deps/
libeio -Idefault -I.. ../deps/libeio/eio.c -c -o default/deps/libeio/
eio_1.o
...

51.
Enki:~/node-v0.4.10 $ make install
Waf: Entering directory `/Users/sh1mmer/node-v0.4.10/build'
DEST_OS: darwin
DEST_CPU: x86
Parallel Jobs: 1
* installing build/default/config.h as /Users/sh1mmer/local/
include/node/config.h
* installing build/default/node as /Users/sh1mmer/local/bin/
node
* installing build/default/src/node_config.h as /Users/sh1mmer/
local/include/node/node_config.h
Waf: Leaving directory `/Users/sh1mmer/node-v0.4.10/build'
'install' finished successfully (0.373s)
Enki:~/node-v0.4.7 $

52.
Enki:~/node-v0.4.10 $ echo $PATH
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/
local/bin:/usr/X11/bin:/usr/local/git/bin:/Users/
croucher/Code/narwhal/bin:/opt/local/bin:/usr/local/
git/bin:/Users/sh1mmer/bin
Enki:~/node-v0.4.10 $ node -v
-bash: node: command not found
Enki:~/node-v0.4.10 $ echo PATH=~/local/bin:$PATH
>> ~/.profile
Enki:~/node-v0.4.10 $ node -v
v0.4.10

53.
System

54.
Enki:~/node-v0.4.10 $ ./configure
...
Enki:~/node-v0.4.10 $ make
...
Enki:~/node-v0.4.10 $ sudo make install
...
Enki:~/node-v0.4.10 $ node -v
v0.4.7
Enki:~/node-v0.4.10 $

55.
Exercise
• Get Node head from Github using
Git
• Install to ~/node

56.
Part 2. Basics

57.
node-repl
Interactive JavaScript terminal

58.
$Enki:~ $ node

59.
$Enki:~ $ node
>3>2>1
false
> true == 1
true
> true === 1
false

60.
> console.log('Hello World');
Hello World
> .help
.clear Break, and also clear the local context.
.exit Exit the prompt
.help Show repl options
> .clear
Clearing context...
> .exit
Enki:~ $

61.
Enki:~ $ node
> var foo = "bar";
> foo;
'bar'
> .clear
Clearing context...
> foo
ReferenceError: foo is not defined
at [object Context]:1:1
at Interface.<anonymous> (repl:98:19)
at Interface.emit (events:27:15)
at Interface._ttyWrite (readline:295:12)
at Interface.write (readline:132:30)
at Stream.<anonymous> (repl:79:9)
at Stream.emit (events:27:15)
at IOWatcher.callback (net:489:16)

62.
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello Worldn');
}).listen(8124, "127.0.0.1");
console.log('Server running at http://127.0.0.1:8124/');

63.
var http = require('http');
//include the http library

64.
http.createServer(function (req, res) {
}).listen(8124, "127.0.0.1");
//create an http server
//when ‘stuff’ happens call this anonymous function
//listen on port 8124 of the IP 127.0.0.1

65.
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello Worldn');
})
//when ‘stuff’ happens my function fires
//I get a request object and a response object
//I write to the response object header
//HTTP status 200 and content-type ‘text/plain’
//close the response with the body:
//Hello World

66.
console.log('Server running at http://127.0.0.1:8124/');
//write Server is running at http://127.0.0.1:8124/
//to the console

67.
Interactive Debugging

68.
Enki:~/Code/node-examples $ node --debug
helloworld.js
debugger listening on port 5858
Server running at http://127.0.0.1:8124/

69.
Enki:~ $ npm install node-inspector
node-inspector@0.1.8 ./node_modules/node-inspector
websocket-server@1.4.04
paperboy@0.0.2
Enki:~ $ node-inspector
visit http://0.0.0.0:8080/debug?port=5858 to start
debugging

70.
Exercises
• Modify the HTTP server to return the text
"I'm learning Node"
• Change the HTTP response to HTML and
return your text in an HTML page
• Return the User-Agent string from the
browser as part of your HTML page
• Return different textual responses to 2 (or
more) browsers

71.
Part 3. Getting Stuck In

72.
HTTP Client

73.
var http = require('http');
var request = http.request({'host': 'www.google.com',
'port': 80, 'path': '/', 'method':'GET'});
request.on('response', function (response) {
console.log('STATUS: ' + response.statusCode);
console.log('HEADERS: ' +
JSON.stringify(response.headers));
response.setEncoding('utf8');
response.on('data', function (chunk) {
console.log('BODY: ' + chunk);
});

74.
Streaming API

75.
write(data)
write(data) Destination
Request
end() (google.com)
response(headers)
data(chunk)
data(chunk)
Response data(chunk)
end()

76.
Exercise
• Fetch the NYTimes.com and output
the contents to the console
• Create a web server
• Create an HTTP client
• POST data to your web server
• Output the POST data to console

77.
Events

78.
object.on('event', function() {
//stuff
} );

79.
EventEmitter

80.
EventEmitter
• manage "event handlers"
• list of functions to be called per
event
• provide mechanism to trigger
events

81.
var util = require('util'),
EE = require('events').EventEmitter;
util.inherits(MyClass, EE);
var myObj = new MyClass();
//nb using first class functions
myObj.on('something', function);

82.
exports.inherits = function (ctor, superCtor) {
ctor.super_ = superCtor;
ctor.prototype = Object.create(superCtor.prototype, {
constructor: {
value: ctor,
enumerable: false
}
});
};

83.
More than just core

84.
CommonJS Modules

85.
Library format for
SSJS

86.
math.js
exports.add = function() {
var sum = 0, i = 0, args = arguments, l = args.length;
while (i < l) {
sum += args[i++];
}
return sum;
};
increment.js
var add = require('math').add;
exports.increment = function(val) {
return add(val, 1);
};
var inc = require('increment').increment;
var a = 1;
inc(a); // 2

87.
Protip
exports.awesome = function() {
//yay my code is awesomesauce
};
var exports.fail = function() {
//exports is a global
//by redeclaring it as
//a local variable
//your code _will_ fail
};

88.
Exercise
• Create a CommonJS module called "fish"
• Provide functions to:
• swim
• mouth breath
• flop around
• Import your module into a node project
• Call the various functions

89.
Node Package
Manager (NPM)

90.
NPM is written in
JavaScript for Node

91.
Enki:~ $ cat `which npm`
#!/usr/bin/env node
;(function () { // wrapper in case we're in module_context mode
var log = require("../lib/utils/log")
log.waitForConfig()
log.info("ok", "it worked if it ends with")
var fs = require("../lib/utils/graceful-fs")
, path = require("path")
, sys = require("../lib/utils/sys")
, npm = require("../npm")
, ini = require("../lib/utils/ini")
, rm = require("../lib/utils/rm-rf")

92.
Enki:~/Code/node(master) $ npm install express
express@2.3.11 ../../node_modules/express
mime@1.2.2
connect@1.4.2
qs@0.1.0
Enki:~/Code/node(master) $

93.
Yay. Easy.

94.
Install instructions
https://github.com/isaacs/npm

95.
Express.js

96.
Sinatra Style MVC
framework

97.
var app = require('express').createServer();
app.get('/', function(req, res){
res.send('hello world');
});
app.listen(3000);

98.
HTTP Verb Oriented

99.
Middleware

100.
app.use(express.bodyParser());
app.use(express.cookieParser());
app.post('/', function(req, res){
// Perhaps we posted several items with a form
// (use the bodyParser() middleware for this)
var items = req.body.items;
console.log(items);
res.send('logging');
});

101.
Templating

102.
var express = require("express");
app.configure(function () {
var public = __dirname + "/../public/";
public = require("path").normalize(public);
app.set("views", __dirname + "/views");
app.set("view engine", "jade");
});
app.get("/", function (req, res) {
res.render("index", {
locals : {
h1: 'Router Stats',
scripts : [
"/public/smoothie.js",
"/public/raphael.js",
"/public/base.js",
"/public/gfx.js",
"/public/explore.js",
"/public/app.js"
]
}
}
});

103.
Exercise
• Create an Express server
• Serve two different pages based on
value of the HTTP Get param "page"
• Create a redirect from /old to /new
• Set a cookie on the client

104.
Express in depth

105.
Routes
• Routes are based on verbs
• GET
• POST
• PUT
• DELETE
• ALL (not a real verb, but obvious)

106.
Simple routes

107.
app.get(‘/’, function(req,res) {
res.send(‘hello root’);
});

108.
Routes with
variables

109.
app.get(‘/user/:id’, function(req,res) {
res.send(‘hello ‘ + req.params.id);
});

110.
Optional flags in
routes

111.
app.get(‘/:filename?’, function(req,res) {
if(req.params.filename) {
res.send(req.params.filename);
} else {
res.send(‘root’);
}
});

112.
Regex as routes

113.
app.get(///, function(req, res) {
//like using ‘/’ ?
res.send(‘/’);
});

114.
app.get(/^/d+/?$/, function(req,res) {
res.send(‘matches a number’);
});

115.
app.get(/^/(.+)/?$/, function(req,res) {
//note translation of %23, etc
res.send(‘Got: ’ + req.params[0]);
//also captures become an array
});

116.
Using regex to
define parameters

117.
app.get(‘/index.:format((html|json))’,
function(req,res) {
res.send('Got: ' + req.params.format);
});

118.
app.get('/:id(d+)', function(req,res) {
//only digits, right?
res.send(req.params.id);
});

119.
app.get('/:id(d+)', function(req,res) {
//escape your in strings
res.send(req.params.id);
});

120.
Routing magic:
Router.js
function normalizePath(path, keys) {
path = path
.concat('/?')
.replace(//(/g, '(?:/')
.replace(/(/)?(.)?:(w+)(?:((.*?)))?(?)?/g, function(_, slash, format, key,
capture, optional){
keys.push(key);
slash = slash || '';
return ''
+ (optional ? '' : slash)
+ '(?:'
+ (optional ? slash : '')
+ (format || '') + (capture || '([^/]+?)') + ')'
+ (optional || '');
})
.replace(/([/.])/g, '$1')
.replace(/*/g, '(.+)');
return new RegExp('^' + path + '$', 'i');
}

121.
Routing magic
• If . before :variable? then . is also optional
• If ? is not after a variable then only the previous character is
affected
• / at the end of URLs automatically optional
• * Can be used as a wildcard in routes
• Includes when end of URL is optional
e.g. '/app/e?'
• Regex can be used any place in a route string
e.g. '/app/(d)r?'

122.
Exercises
• Create an express app with routes that capture '/'
'/products' and '/services'
• Create a route that captures the product ID after
'/product/' e.g. '/product/abc12' and returns it in
the response
• Use a regular expression to restrict the ID
parameter to 3 letter followed by 3-5 numbers
• Create a route using a regex that matches the
entire route

123.
Passing Control
• Routes are actually 'stacked middleware'
• You can pass control between routes
• The next() function calls the next matching
route

124.
app.get('/users/:id', function(req, res, next){
var id = req.params.id;
if (checkPermission(id)) {
// show private page
} else {
next();
}
});
app.get('/users/:id', function(req, res){
// show public user page
});

125.
Passing Control
• next() is a function of router (and defined in the
closure containing the route)
• router will grab routes in the order they were
declared
• e.g. since'/*' will match everything so it should be
the last route!
• router doesn't care about verbs so you can use
all() to operate on all verbs/routes and then use
next() to pass to get(), put(), etc

126.
Exercises
• Create a simple check for correct product
IDs if not pass control to a route showing a
custom error page
• Use app.all() to check user permission
before showing (mock-up) edit controls on
a web site

127.
Middleware

128.
It's a pattern

129.
req, res
next()
next()
next()

130.
req, res
next()
next()
Dispatcher
next() req
res

131.
req, res, next

132.
var express = require('express'),
app = express.createServer();
var middleware = function (req, res, next) {
req.foo = 'bar';
next();
};
app.use(middleware);
app.get('/', function(req, res) {
res.send(req.foo);

133.
var express = require('express'),
app = express.createServer();
var middleware = function (req, res, next) {
var send = res.send;
res.send = function(d) {
res.send = send;
res.send('hijacked! ' + d);
}
next();
};
app.use(middleware);
app.get('/', function(req, res) {
res.send('hi');
});

134.
Connect middleware
(Renamed express.* for convenience)
• logger • profiler
• bodyParser • responseTime
• cookieParser • basicAuth
• session • favicon
• static • vhost
• errorHandler

135.
var express = require('express'),
app = express.createServer();
app.use(express.logger());
app.use(express.bodyParser());
app.use(express.cookieParser());
app.use(app.router);
app.use(express.static(__dirname + '/images'));
app.use(express.errorHandler());
app.get('/', function(req, res) {
res.send('<html><img src="/image.png"></html');
});
app.listen(9003);

136.
Ordering matters

137.
Router uses
"internal
middleware"

138.
var express = require('express'),
app = express.createServer();
var middleware = function (req, res, next) {
req.foo = 'bar';
next();
};
app.get('/', middleware, function(req, res) {
res.send(req.foo);
});

139.
var a, b, c, d;
a = b = c = d = function(req,res,next) {
next();
}
var set1 = [a,b];
var set2 = [c,d];
var all = [set1, set2];
app.get('/set1', set1, function(req,res) {
res.send('output');
});
app.get('/set2', [c,d], function(req,res) {
res.send('output');
});
app.get('/all', all, function(req,res) {
res.send('output');
});

140.
Middleware
factories

141.
Middleware are just
functions

142.
var a, b, c, d;
a = b = c = d = function(req,res,next) {
next();
}
var set1 = [a,b];
var set2 = [c,d];
var all = [set1, set2];
app.get('/set1', set1, function(req,res) {
res.send('output');
});
app.get('/set2', [c,d], function(req,res) {
res.send('output');
});
app.get('/all', all, function(req,res) {
res.send('output');
});

143.
var mFactory = function(letter) {
return function(req,res,next) {
var send = res.send;
res.send = function(d) {
res.send = send;
res.send(letter + ' ' + d);
}
next();
}
};
var set1 = [mFactory('a'),mFactory('b')];
var set2 = [mFactory('c'),mFactory('d')];
var all = [set1, set2];
app.get('/set1', set1, function(req,res) {
res.send('output');
});
app.get('/set2', set2, function(req,res) {
res.send('output');
});
app.get('/all', all, function(req,res) {
res.send('output');
});

144.
Exercise
• Create a middleware to detect mobile
phone browsers and attach a boolean to
req
• Create an express app that serves up links
to an image using staticProvider
• Modify Profiler to profile your app and
write each profile to a log file
• Create a middleware factory that sets the
HTTP Expires header based on roles

145.
Error handling

146.
function NotFound(msg){
this.name = 'NotFound';
Error.call(this, msg);
Error.captureStackTrace(this, arguments.callee);
}
NotFound.prototype.__proto__ = Error.prototype;
app.get('/404', function(req, res){
throw new NotFound;
});
app.get('/500', function(req, res){
throw new Error('keyboard cat!');
});

147.
app.error(function(err, req, res, next){
if (err instanceof NotFound) {
res.render('404.jade');
} else {
next(err);
}
});

148.
View Rendering

149.
app.get('/', function(req, res){
res.render('index.ejs', { title: 'Falsy Demo' });
});

150.
Enki:~/Code/express-demo $ tree
.
app.js
lib
public
views
index.ejs
layout.ejs
layout1.ejs
partials
stylesheet.ejs
4 directories, 5 files
Enki:~/Code/express-demo $

151.
Don't forget to
install
npm install ejs
npm install jade

152.
layout.ejs
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title><%= title %></title>
</head>
<body>
<%- body %>
</body>
</html>

153.
• layout is a framework unless you
turn it off
• body is a special variable for layout
referring to the file specified

154.
app.set('view engine', 'ejs');
app.get('/', function(req,res) {
res.render('index', { title:'Falsy Demo'});
});

155.
//global
app.set('view options'), {
layout: false;
});
//or per route
res.render(index, {layout: false});

156.
Partial views

157.
View Partials
• Repeating elements
• Take a collection
• Iterate over the collection
• "Built in" variables for managing
collections

158.
layout.ejs
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<%- partial('stylesheet', stylesheets) %>
<title><%= title %></title>
</head>
<body>
<h1><%= header %></h1>
<%- body %>
</body>
</html>

159.
partials/stylesheet.ejs
<link rel="stylesheet" type="text/css" href="<%-
stylesheet %>">

160.
res.render('index', {
locals: {'title': title,
'header': header,
'content': content,
stylesheets: ['/public/style.css']
},
}
);

161.
Exercises
• Create an express server that use jade, haml, ejs to
render an index page
• Create a public folder and include file from it (CSS,
images, etc) in your layout
• Create a route for '/blog/id' to accept only digits
• Make a 'fake database' (array) of blog posts and use a
middleware to validate each id is valid
• Create a view for the '/blog/id' show the correct post
• Use a view partial to a preview of each blog post on
the index page

162.
Questions