Building for clients with Node.js

Transcript

1. Building for clients with Node.js @PabloSerbo Paul Serby

2. Overview About us Why node.js Our approach - code examples

   Client projects Pain points - code examples Did we make the right decision?

3. @clock www.clock.co.uk

4. Frontend / Design / UX Backend / Devops Clock Team

5. 1997

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14. Paul Serby http://github.com/serby @PabloSerbo 10 years at Clock CTO since

    2005 Computer Science Degree

15. Why node.js

16. Fatigue

17. None

18. Frontend / Design / UX Backend / Devops Clock Team

19. Frontend / Design / UX Backend / Devops PHP Skills

20. Frontend / Design / UX Backend / Devops JavaScript Skills

21. Community

22. Our approach

23. jade hook.io connect express stylus socket.io mongodb mocha should.js winston

    async underscore jshint

24. Crockford on JavaScript - Act III: Function the Ultimate -

    http://bit.ly/xooF1h Module Pattern Pseudo-classical inheritance - “This was the inheritance scheme that was designed for the language, and I really don't care for it at all. I don't think it looks very good.”

25. var EventEmitter = require('events').EventEmitter; exports.createKitten = function() { var dead

    = false , energy = 0 , kitten = new EventEmitter(); function eat() { deadCheck(); energy += 10; } function run() { deadCheck(); if (energy > 1) { energy -= 1; } else { die(); } } function die() { kitten.emit('died', self); deadCheck(); dead = true; } function deadCheck() { if (dead) { throw new Error('You are dead'); } } kitten.eat = eat; kitten.run = run; return self; }; var util = require('util') , events = require('events'); function Kitten() { events.EventEmitter.call(this); } function deadCheck(kitten) { if (kitten.dead) { throw new Error('You are dead'); } } util.inherits(Kitten, events.EventEmitter); Kitten.prototype.energy = 0; Kitten.prototype.dead = 0; Kitten.prototype.eat =function() { deadCheck(this); this.energy += 10; }; Kitten.prototype.run =function() { deadCheck(this); if (this.energy > 1) { this.energy -= 1; } else { this.die(); } }; Kitten.prototype.die = function () { this.emit('died', this); deadCheck(this); this.dead = true; }; exports.Kitten = Kitten;

26. Inversion of Control

27. var serviceLocator = require('service-locator').createServiceLocator() , foo = 'bar'; serviceLocator.register('foobar', foo);

    console.log(serviceLocator.foobar); // bar serviceLocator.register('logger', console); serviceLocator.logger.log('Hello world'); // Hello world http://github.com/serby/service-locator Inversion of Control

28. Most modules should have exactly 1 export. Module systems should

    be designed around that use case first, not for dozens of exports. substack Separation of concerns if your module exposes more than one function, you might be doing it wrong :) mikeal

29. OBJECT ORIENTED MASTURBATION Playing with yourself

30. Moduleitus exports.createMathLib = function () { var answer = NaN;

    return { sum: function (x, y) { answer = x + y; }, get answer() { return answer; } }; }; var math = require('math-lib').createMathLib() , printer = require('printer').createPrinter(); math.sum(1, 1); printer.setPrefix('The answer is: '); printer.out(math.answer); exports.createPrinter = function() { var prefix = ''; return { setPrefix: function(value) { prefix = value; }, out: function(value) { console.log(prefix + value); } }; }; http://robert.accettura.com/blog/2008/12/16/object-oriented-masturbation/ npm install math-lib npm install printer

31. function sum(x, y) { return x + y; } console.log('The

    answer is: ' + sum(1, 1)); Sanity

32. Client Projects

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34. Usage Stats 104,922 Registrations Ran for 1 month Read: 950

    per second at peak 150 reg per second at

35. Commercial Stats 40% Profit Sun Perks Phase 1 12 Month

    Average 32% Profit
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37. Usage Stats 154,359 Registrations Ran for 3 months Benchmarked at

    250 per second

38. Commercial Stats 31% Profit Sun Perks Phase 2 12 Month

    Average 32% Profit
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40. Commercial Stats 40% Profit Eat Out Phase 1 12 Month

    Average 32% Profit

41. Commercial Stats 55% Profit Eat Out Phase 2 12 Month

    Average 32% Profit

42. Commercial Stats 40% Profit Average over both project

43. Pain Points

44. Async

45. Async

46. Sync var userModel = require('../lib/userModelSync').createUserModel(); module.exports.findMe = function(user){ return userModel.findByEmail(user.email)

    || userModel.findByName(user.name) || userModel.findByGithub(user.github)) || null; };

47. var userModel = require('../lib/userModel').createUserModel(); module.exports.findMe = function(user, callback) { userModel.findByEmail(user.email,

    function(error, foundUser) { if (error) { return callback(error); } if (foundUser === null) { userModel.findByName(user.name, function(error, foundUser) { if (error) { return callback(error); } if (foundUser === null) { userModel.findByGithub(user.github, function(error, foundUser) { if (error) { callback(error); } if (foundUser === null) { callback(null, null); } else { callback(null, foundUser); } }); } else { callback(null, foundUser); } }); } else { callback(null, foundUser); } }); };

48. var userModel = require('../lib/userModel').createUserModel(); module.exports.findMe = function(user, callback) { userModel.findByEmail(user.email,

    function(error, foundUser) { if (error) { return callback(error); } if (foundUser === null) { userModel.findByName(user.name, function(error, foundUser) { if (error) { return callback(error); } if (foundUser === null) { userModel.findByGithub(user.github, function(error, foundUser) { if (error) { return callback(error); } if (foundUser === null) { callback(null, null); } else { callback(null, foundUser); } }); } else { callback(null, foundUser); } }); } else { callback(null, foundUser); } }); };

49. var userModel = require('../lib/userModel').createUserModel(), step = require('step'); module.exports.findMe = function(user,

    callback){ step( function() { userModel.findByName(user.name, this); }, function(error, result) { if (error || result) { this(error, result); } else { userModel.findByEmail(user.email, this); } }, function(error, result) { if (error || result) { this(error, result); } else { userModel.findByGithub(user.github, this); } }, function(error, result) { callback(error, result); } ); }; Step https://github.com/creationix/step

50. var userModel = require('../lib/userModel').createUserModel(), async = require('async'); module.exports.findMe = function(user,

    callback){ var foundUser, foundError; async.detectSeries( [ async.apply(userModel.findByEmail, user.email), async.apply(userModel.findByName, user.name), async.apply(userModel.findByGithub, user.github) ], function (fn, cb) { fn(function(error, user) { foundUser = user; foundError = error; cb(foundError || user); }); }, function(result) { callback(foundError, foundUser); } ); }; async https://github.com/caolan/async

51. var userModel = require('../lib/userModel').createUserModel(); module.exports.findMe = function(user, callback){ var fns

    = [ userModel.findByEmail.bind(this, user.email), userModel.findByName.bind(this, user.name), userModel.findByGithub.bind(this, user.github), function() { return callback(undefined, null); } ]; function detect(error, user) { if (error || user) { return callback(error, user); } fns.shift()(detect); } detect(); }; none

52. var userModel = require('../lib/userModel').createUserModel(), chain = require('jangle').chain; module.exports.findMe = function(user,

    callback){ chain() .seq(userModel.findByName, user.name) .seq(userModel.findByEmail, user.email) .seq(userModel.findByGithub, user.github) .detect(function(error, returnedUser) { return returnedUser; }) .run(callback); }; jangle https://github.com/serby/flow-control-examples

53. NPM Modules http://www.mikealrogers.com/posts/nodemodules-in-git.html

54. NPM Modules http://www.mikealrogers.com/posts/nodemodules-in-git.html GIT

55. Did we make the right decision?

56. Questions?