All aboard the NodeJS Express

All aboard theNode.JSExpress#SotR14

You know Node?Kev McCabe is covering TDD

SotR14 - Mura Room

Who is this guy?David Boyer

Senior SoftwareDeveloper

NHS Wales InformaticsService

...and yes... that'sme in the mask @

SotR13

Node.jsA JavaScript runtime

http://nodejs.org

The DetailsJavaScriptGoogle's V8 engineOpen Source - MIT LicenseCross platformSingle threaded codeMulti threaded IO

What can it do?Build web applications

Creating command line toolsCreate desktop applications

(node-webkit)

Who is using it?PayPal, LinkedIn, Yahoo, Microsoft,

eBay, 37signals, LearnBoost,Yammer, Walmart

Node in detail

In the beginning...Install

Command line

Action!*nodeconsole.log('Hello Scotch');

Using the APIvar fs = require('fs'); // Filesystem APIvar http = require('http'); // http APIvar crypto = require('crypto'); // Crypto API

One thread to rulethem all!

One thread for JavaScriptMultiple threads for I/O

The Event LoopEventQueue

Single js thread MultipleI/OThreads

What does the code looklike?

var fs = require('fs');var rawData = fs.readFileSync('sotr.json');var data = JSON.parse(rawData);console.log(new Date());console.log(data.message);

Why not just be multi-threaded?

Each thread needs morememory

Switching between threadscosts CPU

Avoids thread safety issues

Scaling single threadsThe Cluster API

↗ ⇶ →

↘

var cluster = require('cluster');var http = require('http');var cpus = require('os').cpus().length;

if (cluster.isMaster) { for (var i = 0; i < cpus; i++) { cluster.fork(); } cluster.on('exit', function(worker, code, signal) console.log('Process ID ' + worker.process.pid + });} else { http.createServer(function(req, res) {...}).listen(}

Switching mindsetFrom sync to async

Lots of callbacksCallback Hell!

Highway to Hellfs.readFile('sotr.json', function(err, data) { var info = JSON.parse(data); db.findOne({id: info.id}, function(err, record) fs.writeFile('sotr.dat', record.title, function console.log('Finish job'); }) })})

Escape from NestedCallbacksBreak it apart

Use a async module like"async"

PromisesGenerators (ES6)

Node as a webapplication

var http = require('http');

var server = http.createServer(function(req, res) res.end('Hello Scotch!');});

server.listen(80);

Modules// conf.jsfunction Conference(name, year) { this.name = name; this.year = year;};Conference.prototype.getTitle = function() { return this.name + ' ' + this.year;};module.exports = Conference

// index.jsvar Conf = require(__dirname + '/conf.js');var sotr = new Conf('Scotch on the Rocks', 2014);console.log(sotr.getTitle());

npmThe Node.js Package Manager

Initialise yourproject

npm init

name: (conference) sotr-exampleversion: (0.0.0) 0.1.2description: An example projectentry point: (index.js) index.jstest command: grunt nodeunitgit repository: git://github.com/misterdai/isnota.git#masterkeywords: example, appauthor: David Boyerlicense: (BSD-2-Clause) MIT

Finding moduleshttps://npmjs.org

https://nodejsmodules.org/http://eirikb.github.io/nipster/

Common modulesDatabases: mysql, mongodb,

sqliteCallbacks: async, q, when, co

Testing: Mocha, nodeunit,should

Templating: Jade, handlebars,ejs

Web frameworks: express,geddy, sails

Installing modulesnpm install asyncnpm install --save coffee-scriptnpm install --save-dev grunt-imagemin

npm install

npm uninstall --save coffee-script

Installing commandsnpm install -g coffee-scriptnpm uninstall -g grunt-clinpm install -g gulp

Other npm superpowers

Publish modulesExecute scripts (e.g. npm build,

npm run)Bump your version number

(semver)

SummaryLet npm manage your modules

Use it to install useful toolssuch as grunt

Don't have to keepnode_modules in source

controlStore project related

commands in package.json

Express yourselfExpress, a web framework for

Node.jsVery flexible

Minimal

Version 4Bundled middleware are nowtheir own modules*.* Except "static".More robust routing.app.router() is gone andmore flexible methods are nowavailable.

Installingmkdir websitecd websitenpm initnpm install --save expresstouch index.js

A static siteServing static files from a

directory

A dynamic siteJavaScript providing the content

A template enginehttps://github.com/visionmedia/consolidate.jsJade, EJS (Embedded JavaScript),

Handlebars...

Try being MEAN!

Popular stack for building Node.jsbased web apps.

MongoDBE xpressA ngularJSN ode.js

Thanks forlistening to my

first everconference talk

Questions

If we have time...

...or catch me at the bar .

GAME OVERAll aboard the

NodeJS ExpressDavid "Mister Dai"

Boyer @misterdai