JavaScript on the Command Line & PRATIK PATEL CTO TripLingo Labs

Transcription

1 JavaScript on the Command Line & TripLingo Labs

2 Topics Modern JavaScript Why? Ecosystem Node Grunt

3 Yesterday s JavaScript

4 Today s JavaScript is cool

5 What s changed?

6 No Change JavaScript is essentially the same language as it was when invented 20 years ago

7 We ve changed JavaScript developers today understand: - Best Practices - Tooling - JavaScript Runtimes today are awesome

8 What hasn t changed JavaScript still has bad parts Async, event-driven programming model

9 How it run outside the browser?

10 V8 Super duper fast JavaScript runtime from Google Runs in the browser

11 Node.js uses V8

12 What about the JVM? Built into the JVM for years Rhino (current) Nashorn (next gen)

13 Why JavaScript on the server?

14 Why JS Single language for the browser & server Fast Scalable

15 ISOMORPHIC APPS

16 Isomorphic Apps Code can run either on the browser or server

17 Traditional Webapp

18 Isomorphic

19 Why Isomorphic? Flexibility Performance

20 Frameworks

21 Ecosystem

22 JavaScript Ecosystem Node NPM - node packaged modules Express - web framework Grunt - task runner / automation

23 Node.js JavaScript runtime based on V8

24 NPM Module / Package manager for node

25 Express Basic server-side web framework for Node

26 Grunt Task runner Automation build scripts

27 Node.js

28 Node.js Install from nodej.org Install using brew on Mac OSX

29 Node.js Command-line centric

30 Running Node Script $ node test3.js Hello Bangalore - test3.js: console.log('hello Bangalore')

31 Package.json // describes this node project, place in base folder { "name": "hello-world", "description": "hello world test app", "version": "0.0.1", "private": true, "dependencies": { "express": "3.x" } }

32 NPM

33 NPM Installed with Node.js Basic package management

34 Running NPM $ npm ls $ npm install lodash -g

35 Express

36 Express Very basic server-side Web Framework Lots of other options: - Sails.js - CompoundJS - Geddy

37 Express Implements event-loop model that is basis of Nodejs Async Event-driven Super-scalable

38 Express App $ cat hello-world/package.json { "name": "hello-world", "description": "hello world test app", "version": "0.0.1", "private": true, "dependencies": { "express": "3.x" } } $ npm install $ npm app Express server listening on port 3000

39 Quick Express Code Walkthrough

40 Grunt

41 Grunt Task based command-line build tool

42 What uses? Unit test running JavaScript linting Minification (both for browser and node.js) CI

43 package.json "devdependencies": { "grunt": "~0.4.2", "grunt-contrib-jshint": "~0.6.3", "grunt-contrib-nodeunit": "~0.2.0", "grunt-contrib-uglify": "~0.2.2" }

44 Gruntfile module.exports = function (grunt) { grunt.initconfig({ jshint: { all: ['Gruntfile.js', 'lib/**/*.js', 'test/**/*.js', 'public/**/*.js', 'routes/*.js', 'routes/**/*.js', 'app.js'] } }); grunt.loadnpmtasks('grunt-contrib-jshint'); grunt.registertask('default', ['jshint']); };

45 Run Grunt $ grunt Running "jshint:all" (jshint) task Linting app.js...error [L12:C20] W033: Missing semicolon. var app = express() Warning: Task "jshint:all" failed. Use --force to continue. Aborted due to warnings.

46 OH NO

47 Fix & re-run Grunt $ grunt Running "jshint:all" (jshint) task >> 4 files lint free. Done, without errors.

48 Closing thoughts Node is not for every kind of app Must consider carefully where to use it Callback hell because Async

49 Bye Follow me on