Node.JSNode.jsisanopensource,cross-platform,JavaScriptruntimebuiltonChrome'sV8JavaScriptengine,fordevelopingserverandclientsideapplications.Node.jsusesanevent-driven,non-blockingI/Omodelthatmakesitlightweightandefficient.

Node’sgoalistoprovideaneasywaytobuildscalablenetworkprograms

Install Node.jsFrom

http://nodejs.org

ConsoleUse

ExitConsole

RunFile

LoadFile

Non-Blocking

REQUESTS

EVENT LOOP(single thread)

EXPENSIVEOPERATION

FILE SYSTEM

DATABASE

COMPUTATION

ArchitecturalShift1.old) webserverwithapplicationlogic1.new) appthatcanconnectandcollaborate

2.old) stateful2.new) stateless

ArchitecturalShift1.old) blocking1.new) non-blocking

2.old) processperrequest2.new) singleprocess

MODULES

Packagemanager.Installs,publishesandmanagesnodeprograms

Whatisnpm?

https://www.npm

js.com

Whatisnpm?LargestEcosystem

475KModules2.7Billion/Week

Advantages• Smallpieces,looselyjoined• Leverageexternalpackages• Leverageinternalpackages• Facilitatecollaboration• Packagesarediscoverableinnpm

WhatisaModule?AModuleissomeJavaScriptpairedwithapackage.jsonfile

+

Make module with “module.exports”

Use module with “require”

Creatingnode/npmapps

“npm init” generates the configuration file package.json

addingnpmpackagestoyourapplication

Local installation of request package. Dependency added to package.json

ActiveLearning• …