Introduction to Node.js
0 likes912 views
The document provides an introduction to Node.js, describing its origins as a way to run JavaScript on the server side using Google's V8 JavaScript engine, its focus on event-driven and asynchronous programming using callbacks, and popular uses of Node.js including web frameworks like Express and databases through modules like Redis. Common tools for Node.js development include the package manager NPM and testing frameworks like Mocha and NodeUnit.
Introduction to Node.js
- 2. Who Developer for Kainos (Java, Scala, Rails, JavaScript, HTML, CSS) Student at University of Bath Write a lot about JavaScript at www.javascriptplayground.com @Jack_Franklin on Twitter
- 3. Origins of Node Server side JavaScript done right runs on Chrome's V8 Engine (it's quick) Evented I/O - runs single non-blocking thread with event loop this is great as JS was designed to be run in a single thread environment (browser)
- 4. Node right now V0.8 standardised the API (non breaking) currently V0.8.4, much more stable than < 0.8 Install via installers, from source or via package manager like Brew.
- 5. NPM Package Manager for Node (think rubygems / bundler for Node) Full of really useful modules (and some less useful ones) 12,627 packages as of yesterday (browse at http://search.npmjs.org/)
- 6. Event Driven JavaScript Learn to think Asynchronously "Once node has completed a task, the callback for it is fired. But there can only be one callback firing at the same time. Until that callback has finished executing, all other callbacks have to wait in line. In addition to that, there is no guarantee on the order in which the callbacks will fire." From: http://debuggable.com/posts /understanding-node-js:4bd98440-45e4-4a9a- 8ef7-0f7ecbdd56cb Related: Async.js https://github.com/caolan/async/
- 7. Callbacks Lots and lots of callbacks var net = require('net'); var server = net.createServer(function (socket) { socket.write('Echo serverrn'); socket.pipe(socket); }); server.listen(1337, '127.0.0.1'); How to avoid: http://callbackhell.com/
- 8. Naming your Callbacks Did you know you can name them? var net = require('net'); var server = net.createServer(function writeResponse(socket) { socket.write('Echo serverrn'); socket.pipe(socket); }); server.listen(1337, '127.0.0.1');
- 9. Avoiding Callbacks: Modules "Write small modules that each do one thing, and assemble them into other modules that do a bigger thing. You can't get into callback hell if you don't go there." Isaac Schlueter - Node.js core contributor @izs write your code in a file like normal: //file socket-module.js function writeResponse(socket) { socket.write('Echo serverrn'); socket.pipe(socket); });
- 10. module.exports = { resp: writeResponse } (this follows the CommonJS module structure) require and use it var net = require('net'); var socketModule = require('socket-module'); var server = net.createServer(socketModule.resp); server.listen(1337, '127.0.0.1');
- 11. Databases with Node Redis & the Redis NPM Package is awesome Adapters for all common DB solutions
- 12. Web Frameworks Most popular is Express JS - www.expressjs.com Loads out there - Google "node js framework" Geddy, Flatiron, RailwayJS Tools like this are slowly but surely maturing
- 13. Express var app = express.createServer(); app.get('/', function(req, res){ res.send('Hello World'); }); app.listen(3000); routing, views (Jade), etc very extensible
- 14. About to hit V3
- 15. Unit Testing NodeUnit https://github.com/caolan/nodeunit Mocha http://visionmedia.github.com/mocha/ Lots more. Find one that suits (I love Mocha)
- 16. In the wild JSBin by @rem - www.jsbin.com - pure awesomeness TweetDig by @mheap - www.tweetdig.com - 2.5m tweets per day
- 17. To Sum Up Node is still very young, although standards and conventions are beginning to be defined. Lack of resources is slowly becoming less of an issue. V0.8 is huge improvement on prior versions. Node is seriously quick if used properly.
- 18. Further Resources @Peepcode screencasts www.peepcode.com CodeSchool Node course www.codeschool.com Async JavaScript book from Trevor Burnhan www.leanpub.com/asyncjs How to Node blog www.howtonode.org/
- 19. Any Questions? Slides on Github: gist.github.com/jackfranklin www.javascriptplayground.com for JavaScript tutorials (including Node) @Jack_Franklin if you can put up with even more of me rambling