Programming for Chaos

An introduction to Node.js

Transcript

1. Node.js Programming for Chaos
2. Who is this bloke? London-based Ruby and JavaScript developer at pebble {code} Currently authoring Sam's Teach Yourself Node.js in 24 Hours. @shapeshed in the usual places
3. Don't Believe The Hype <3 <3 ZOMG THE New Railsz !!!! Make Startup with Node.js === Profit I AM Node.js I AM HIPSTER!!!
4. Let's Chat! http://192.168.3.1
5. The Web Started Simple HTML Browsers http://
6. Then Became Dynamic cDatabases c Scripting Languages
7. It is different now
8. I'm easily excited
9. I'm cheap Galaxy Apollo £30 (refurb) • Clients are capable • Clients can be servers
10. Learning from gaming 10 PRINT "HELLO LONDON WEB!" 20 GOTO 10
11. Your are in a large empty room There are exits to the left or right. Left or right?
12. Input / Output Logic Left Princess!
13. This is predictable • Map scenarios • Write Code • Easy!
14. We even write tests for this Scenario: Player Turns Right Given I am asked to turn left or right When I choose to turn right Then I should see “Eaten by a dragon” Scenario: Player Turns Right Given I am asked to turn left or right When I choose to turn left Then I should see “You found the Princess”
15. Stop playing with yourself More difficult
16. Atari Joystick Joystick Output Logic Input(s)
17. Xbox Controller Internet 8 million controllers Game Servers Databases Chat Servers Voice Servers Load Balancers Message Queues More..
18. A little language called JavaScript var perception = "Toy browser language"; var reality = "The language of the web";
19. Browser wars V8 JavaScript Engine • Super fast • Highly performant • Open source
20. A love-child is born var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }).listen(1337, '127.0.0.1'); console.log('Server running at http://127.0.0.1:1337/');
21. Why JavaScript? Callbacks $("p").hide(1000); alert("This paragraph is hidden"); $("p").hide(1000, function(){ alert("This paragraph is hidden"); });
22. Why JavaScript? The Event Loop • Single Threaded • Return fast • Don't Block
23. Blocking var fs = require('fs'); var data = fs.readFileSync(__dirname + '/example.file','utf8'); console.log(data);
24. Non-blocking var fs = require('fs'); fs.readFile(__dirname + '/example.file', 'utf8', function (err, data) { if (err) { return console.log(err); } console.log(data); });
25. You talk a lot. Show me something!
26. Node.js is a platform for • Network programming • Real-time • High data throughput • Many concurrent users (It is one approach to concurrency)
27. When to use Node.js • Single page applications • Real-time games • Network Mashups • Data streaming (file uploads) • JSON APIs
28. When not to use Node.js • CPU intensive applications • CRUD apps on relational databases • Simple HTML sites • Just because 'IT IS SO HOT RIGHT NOW!'
29. Where next? • Express • https://github.com/visionmedia/express • Socket.IO • http://socket.io/ • dnode • https://github.com/substack/dnode • UK Training • http://leftlogic.com/training#node
30. Thanks! @shapeshed Slides: http://bit.ly/J9Qvbh