TechTalk: Node.js Jessica Davis, Juan Herrera, Ian Hoyt-McCullough, Varun Verma - PowerPoint Presentation

Slide1

TechTalk: Node.js

Jessica Davis, Juan Herrera, Ian Hoyt-McCullough, Varun Verma

Overview of Node.js

What is Node.js?

An open-source, cross-platform JavaScript run-time environment that executes JavaScript code in a computing environment

What is Node.js capable of doing?

Generating dynamic page content

Creating, opening, reading, writing,, deleting, and closing files on the server

Collecting form data

Adding, deleting, modifying data in your database

What operating systems officially support Node.js?

Linux, macOS, Microsoft Windows, and more

How is Node.js primarily used?

To build network programs, like web servers

History of Node.js

2009: Originally written by Ryan Dahl

Initial release supported on Linux and Mac OS X

Created after seeing a file upload progress bar on Flickr

Had to query the Web server for more information about the file

Node.js is a combination of:

Google’s V8 JavaScript engine

An event loop

A low-level I/O API

January 2010: npm was released as a package manager for Node.js

June 2011: Node.js was expanded to support more operating systems

Demo

A short demo…

npm init

npm scripts (npm start, npm test)

npm install <module> (nodemon)

Server code (next slide)

Dependencies (package.json)

Demo

var http = require('http');

http.createServer(function (req, res) {

res.writeHead(200, {'Content-Type': 'text/html'});

res.end('Hello world!');

}).listen(8000);

Pros

Javascript easy to learn for front-end developers

Compiles directly into machine code

Many resources and support available

High support for asynchronous events

Handles concurrent requests sequentially in a single thread, using less RAM and system resources

Cons

Cons

The single-threaded design can create bottlenecks when used in tasks with lots of computation

Must be careful dealing with exceptions in code, as uncaught ones may “bubble up” to the core node.js loop and crash the program for all requests

Coding paradigm is highly reliant on asynchronous callbacks, or functions run after certain functions return, so the scope and dependencies in the code can quickly become confusing, resulting in “callback hell” (need to learn to effective use of Promises in order to counteract this)

Alternatives/Competition

Ruby on Rails

Good for flexible databases

Worse performance than Node.js

Django

Highly Scalable

Monolithic, not fit for small apps

Flask

Minimalist, easy to learn

Not much Asynchronous support

Php

SQL integration is very simple, huge existing codebase

Not as powerful or flexible as Node.js

Use Cases

Good for streaming

Audio and Video files

Web apps similar to SoundCloud & Youtube

Specially suited for applications where you want to maintain persistent connection from the browser to server

Real-time updates

Online games

Collaborative tools

Chat interfaces

Gmail for instance

Cases of rapid development due to an extensive NPM ecosystem and ease of configuration

Cheaper cloud hosting

Desire a highly scalable application

Unified JavaScript development platform as it integrates well with MongoDB, AngularJS, & ReactJS

Use Cases

-Uber: Instantaneous real time updates, non-blocking

-Netflix: Handles the real time audio & video streaming efficiently

-LinkedIn: Efficiency & scale. Servers cut down from 15 to 4, & traffic capacity doubled

-NASA: Reduced access time by 300%. This is due to the persistent connection maintained by the server

Use Case Chat Example: Event Driven Apps

var

app =

require

(

'express'

)();

var

http =

require

(

'http'

).Server(app);

var

io =

require

(

'socket.io'

)(http);

app.get(

'/'

,

function

(

req, res

)

{

res.sendFile(__dirname +

'/index.html'

);

});

io.on(

'connection'

,

function

(

socket

)

{

console

.log(

'an user connected'

);

socket.on(

'disconnect'

,

function

()

{

console

.log(

'user disconnected'

);

});

});

http.listen(

3000

,

function

()

{

console

.log(

'listening on *:3000'

);

});

Use Case Chat Example: Event Driven Apps

Any Questions?

Sources/References

https://www.mindinventory.com/blog/pros-and-cons-of-node-js-web-app-development/

https://www.netguru.com/blog/pros-cons-use-node.js-backend

https://medium.com/the-node-js-collection/why-the-hell-would-you-use-node-js-4b053b94ab8e

https://www.w3schools.com/nodejs/nodejs_intro.asp

https://en.wikipedia.org/wiki/Node.js#Overview

https://medium.com/@TechMagic/nodejs-vs-ruby-on-rails-comparison-2017-which-is-the-best-for-web-development-9aae7a3f08bf

https://dzone.com/articles/nodejs-vs-djangois-javascript-better-than-python

https://www.codingdojo.com/blog/choosing-python-web-frameworks