HELLO WORLD

Jeff AndersenDeveloperTwitter: @jeffandersen Email: jeff@goinstant.com

What is Node.js?• In a nutshell: server-side JavaScript

• Used to build scalable network applications

• Built on Google’s v8 JavaScript engine

• Event-driven, non-blocking (asynchronous) I/O

Who uses it?

Installing Node.js• Visit nodejs.org

• Download the package/installer and run

• Alternatively: use nvm - Node Version Manager (Similar to Ruby’s RVM) https://github.com/creationix/nvm

Test out the repl• From the command line type `node`

• Type out commands and hit enter

Use cases• REST APIs

• Streaming data

• High concurrency

• Leveraging UNIX tools

• Realtime applications

Event Driven

Event Driven

Sync vs Async

Synchronous (Blocking)

Asynchronous (Non-Blocking)

Asynchronous (Non-Blocking)

• Node is built for async i/o

• Sometimes difficult to understand

• Callback soup

Let’s run it

HTTP Server

5 lines of codeLet’s run it

HTTP Server

Community / Ecosystem

http://notinventedhe.re/on/2011-7-26

• npmjs.org

• Open source software

• Official package manager for Node.js

• Nearly 55 thousand packages and almost 2.5 million downloads per day

• package.json

Package.json

npm install

Recommended Modules• async - Higher-order functions and common patterns for

asynchronous code

• lodash - A utility library delivering consistency, customization, performance, & extras.

• express - Sinatra inspired web development framework

• mocha - simple, flexible, fun test framework

• pg - PostgreSQL client

• redis - Redis client

Example app

Example appBasic REST api

What do we need?• HTTP server

• Postgres database

• Postgres client

• JSON formatted responses

We have an HTTP server

Problems?• One handler replying to every request

• Missing

• Routing/URL parameters

• Response formatting

• npm install express

• Sinatra style web framework

• Simple verb-based request handlers

• Full-featured router

• body parser, url parameters, query string parsing

• Automatic response formatting

Introducing Express

Same functionality

Let’s code

What could be added?• OAuth middleware

• Middleware: A function that processes a request, typically on an interim basis to the final request handler.

• Permissions & token scopes

• JSON web hooks

Twitter recommendations• @izs - Isaac Schlueter, Creator of NPM & Node core gate keeper

• @eranhammer - Eran Hammer, Walmart Labs & OSS contributor

• @substack - James Halliday, Node module authoring machine

• @tjholowaychuk - TJ Holowaychuk, Author: Express, Mocha, etc

• @igrigorik - Ilya Grigorik, Developer advocate at Google

• @jeresig - John Resig, Creator of jQuery

• @goinstant - Realtime Collaboration API and Backend