Objectives

• Understand the role Node plays in server side JS and list 3 differences from client side JS
• Define and describe npm
• Setup a node project directory
• Include core fs module in a program via require

Powered by:

NodeJS

# Search for packages related to V8

# Arch Linux
$ pacman -Ss v8
    community/nodejs 6.3.1-1
        Evented I/O for V8 javascript

NodeJS vs Browsers

• Runs as a standalone program
  • Can start/stop/suspend
  • Not tied to a parent program
  • Access to things like screen brightness
• No DOM or other Browser Libraries
  • No document object
  • No window object
  • No JQuery
• CommonJS Module System
  • Use require to import a module

Node Package Manager

global vs. local installs

npm install http-server -g

npm install http-server

vs.

npm install -g typescript

installs to /usr/local

npm install gulp

installs to ./node_modules

Anyone Can Publish!

Project Setup

Project Setup

1. Make folder
2. Change to the folder (cd/pushd)
3. Create your initial source file
4. Initialize the package (npm init -y)
5. Add a .gitignore file
6. Add dependencies (if any)

package.json

The "manifest" for the package which contains

• Name
• Description
• dependencies
• License
• and much more

package.json

For more information see:

npm help 5 package.json

and

http://browsenpm.org/package.json

CommonJS Modules

Included in your program via require

"Encapsulates" code in re-useable units

CommonJS Modules

let fs = require("fs");
let path = require("path");

const log = console.log;

const inputFile = "data.json";

fs.readFile(inputFile,(err,data)=>{
    if(err) {
        throw err;
    }
    else {
        log(data);
    }

});