Hackference Talk

talk.md

Embracing Chaos with JavaScript

George Ornbo @shapeshed

Hackference, Birmingham 30th August 2013

A brief history

• HTML born
• Databases and scripting languages
• APIs
• Ajax
• Web Standards
• JavaScript

Status quo

• Everything is networked
• Everything is connected all the time
• Everyone has superpowers in their pockets
• More wearable (and embeddable?) tech to come
• We have an amazing platform to hack on

But there are still limitations

• Browsers
• Databases
• File Systems
• Networks

Flip to games

• PRINT 10 'YOU ARE IN A ROOM'
• Chess
• Street Fighter
• MMORPG
• Total mania

What tools do we have to respond to this?

• HTTP 1.1
• WebSockets, SSE
• Crappy browsers (still)

So how do we make sense of this?

• Events
• An example from the browser

    $('p').hide('slow');
    alert("The paragraph is now hidden");

    $('p').hide('slow', function() {
      alert("The paragraph is now hidden");
    });

• An example on the server

    var http = require('http');

    http.createServer(function (req, res) {
      res.writeHead(200, {'Content-Type': 'text/plain'});
      res.end('Hello Hackference!\n');
    }).listen(3000, "127.0.0.1");

Node.js is one approach

• JavaScript API into C++ bindings to V8
• Created by Ryan Dahl
• V8 is Chrome's JavaScript Engine
• Small core, big userland
• UNIX philosophy of doing one thing well

What can you hack on with node?

• Software
  • Quick HTML Prototypes
  • REST APIs
  • Realtime
  • Data-streaming
• Hardware
  • Arduinos
  • Quadcopters
  • Serial Ports

npm - node's second best feature

• Package manager
• npm install foo
• npm publish
• For client-side too (with bower)

Using node for JS tooling

• Grunt
• JSHint
• grunt-* tools
• Testing
• Building

Streams - node's best feature

• Washing your car. Bucket or hose.
• Using data when it is ready
• API stabilising
• Most things in node are a stream

    var fs = require('fs');

    var stream = fs.ReadStream('enormous.txt');

    stream.setEncoding('utf8');

    stream.on('data', function(chunk) {
      console.log('read some data')
    });

    stream.on('close', function () {
      console.log('we are done')
    });

• Like UNIX you can pipe

    var http = require('http'),
        fs = require('fs');

    http.createServer(function(request, response) {
      var mp3 = 'birdie-song.mp3';
      var stat = fs.statSync(mp3);

      response.writeHead(200, {
        'Content-Type': 'audio/mpeg',
        'Content-Length': stat.size
      });

      var readableStream = fs.createReadStream(mp3);
      readableStream.pipe(response);

    }).listen(3000);

Some things to know

• The server and the application are one process
• Self-hosting can be tricky
• Heroku and Nodejitsu offer free hosting
• There isn't a Rails equivalent in node.js
• Callbacks
• CoffeeScript

Who is using node?

• eBay
• Yahoo
• Voxer
• LinkedIn

Where can I find out more?

• Start with Express
• IRC, Mailing lists, blog posts
• Books
• But most of all hack!

Over to Andrew.

• Andrew likes bunnies
• Andrew makes a mean chocoloate brownie
• Andrew organises LNUG and The Great British Node Conf
• He has drones!