The first talk from the "Empower on Rails" Ruby on Rails seminars.

1. presents
Ruby on Rails 3.1
Let’s bring the fun back to web programming!
Bozhidar Batsov
Technical Lead

2. The problem

3. Many programmers are
not particularly happy

4. It's the question that drives
us, Neo. It's the question that
brought you here. You know
the question, just as I did.
What is the question?

5. How can I be
be one happy
(web) programmer?

8. VS. VS.

9. VS. VS.

11. This PHP code is so
clean and elegantly
solves the problem at
hand.
Nobody, Never

12. PHP
0 10 20 30 40 50 60 70 80 90 100
OOP
FP
Performance
Productivity
Fun

15. The Zen of Python
There should be one –
and preferably only one
– obvious way to do it.

16. Python
0 10 20 30 40 50 60 70 80 90 100
OOP
FP
Performance
Productivity
Fun

18. The Web framework for
perfectionists with
deadlines.

19. 2007

21. A Programmer’s Best Friend

22. The goal of Ruby is to make
programmers happy. I started out
to make a programming language that
would make me happy, and as a side
effect it’s made many, many programmers
happy. Especially Web
developers.
Yukihiro “Matz” Matsumoto,
creator of Ruby

23. Ruby
0 10 20 30 40 50 60 70 80 90 100
OOP
FP
Performance
Productivity
Fun

24. PHP Python Ruby
0 10 20 30 40 50 60 70 80 90 100
OOP
FP
Performance
Productivity
Fun

25. Startup Technologies 2011
30
27
24
21
18
15
12
9
6
JQuery 3
Django 0
Ruby on Rails

27. http://www.ruby-toolbox.com

29. “Rails is the most well thought-out web
development framework I’ve ever used. And
that’s in a decade of doing web applications for
a living. I’ve built my own frameworks, helped
develop the Servlet API, and have created more
than a few web servers from scratch. Nobody
has done it like this before.”
James Duncan Davidson, Creator of Tomcat
and Ant

30. “Ruby on Rails is a breakthrough in
lowering the barriers of entry to
programming. Powerful web
applications that formerly might have
taken weeks or months to develop can
be produced in a matter of days.”
Tim O'Reilly, Founder of O'Reilly
Media

31. “It is impossible not to notice Ruby on
Rails. It has had a huge effect both in
and outside the Ruby community...
Rails has become a standard to which
even well-established tools are
comparing themselves to.”
Martin Fowler, Author of
-
Refactoring, PoEAA, XP Explained

32. “Rails is the killer app
for Ruby.”
Yukihiro Matsumoto,
Creator of Ruby

33. Convention
over
Configuration

34. DRY
(Don’t
repeat
yourself)

36. Many view (template)
options
HTML + Erb Haml
<div id="profile"> #profile
<div class="left column"> .left.column
<div id="date"><%= print_date %></div> #date= print_date
<div id="address"><%= current_user.address %></div> #address= current_user.address
</div> .right.column
<div class="right column"> #email= current_user.email
<div id="email"><%= current_user.email %></div> #bio= current_user.bio
<div id="bio"><%= current_user.bio %></div>
</div>
</div>

37. doctype html
html
head
title Slim Core Example
meta name="keywords" content="template language"
body
h1 Markup examples
div id="content" class="example1"
p Nest by indentation
== yield
- unless items.empty?
table
- for item in items do
tr
td = item.name
td = item.price
- else
p
| No items found. Please add some
inventory.
Thank you!
div id="footer"
| Copyright © 2010 Andrew Stone
= render 'tracking_code'
javascript:
$(content).do_something();

38. Testing in Rails is not
optional!

39. All the code
is guilty until
proven
innocent!

40. DSL FTW

41. ActiveRecord
class Page < ActiveRecord::Base
has_many :page_images, :dependent => :destroy
validates :title, :presence => true, :uniqueness => true
validates :content, :presence => true
validates :permalink, :presence => true, :uniqueness => true
accepts_nested_attributes_for :page_images, :allow_destroy => true
def to_param
permalink
end
end

42. XML Free
development:
adapter: postgresql
database: mycoolproject
host: localhost
username: mycoolproject
password: mycoolproject
encoding: utf8
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000

43. UNIX Certified
rails g (generate)
rails c (console)
rails db (dbconsole)
rake
bundle

44. Agile

45. Innovation

46. Lots of
friends

47. Fo
r k
me
on
Git
Hu
b!

48. Fantastic documentation
RailsGuides (http://guide.rubyonrails.org)
RailsCasts (http://railscasts.org)
PragProg
Ruby on Rails 3 Tutorial (http://ruby.railstutorial.org/)

49. The Dark Art of
Deployment

52. In the clouds...
?

53. $ heroku create --stack cedar
$ git push heroku master
$ heroku open
$ heroku scale web=100 worker=50

54. Happy programmers

55. Rails 3.1

56. CoffeeScript
# Assignment:
number = 42
opposite = true
# Conditions:
number = -42 if opposite
# Functions:
square = (x) -> x * x
# Arrays:
list = [1, 2, 3, 4, 5]
# Objects:
math =
root: Math.sqrt
square: square
cube: (x) -> x * square x
# Splats:
race = (winner, runners...) ->
print winner, runners
# Existence:
alert "I knew it!" if elvis?
# Array comprehensions:
cubes = (math.cube num for num in list)

57. JavaScript
var cubes, list, math, num, number, opposite, race, square;
var __slice = Array.prototype.slice;
number = 42;
opposite = true;
if (opposite) number = -42;
square = function(x) {
return x * x;
};
list = [1, 2, 3, 4, 5];
math = {
root: Math.sqrt,
square: square,
cube: function(x) {
return x * square(x);
}
};
race = function() {
var runners, winner;
winner = arguments[0], runners = 2 <= arguments.length ? __slice.call(arguments, 1) : [];
return print(winner, runners);
};
if (typeof elvis !== "undefined" && elvis !== null) alert("I knew it!");
cubes = (function() {
var _i, _len, _results;
_results = [];
for (_i = 0, _len = list.length; _i < _len; _i++) {
num = list[_i];
_results.push(math.cube(num));
}
return _results;
})();

58. Asset Pipeline

59. SASS
$blue: #3bbfce; .content-navigation {
$margin: 16px; border-color: #3bbfce;
color: #2b9eab;
.content-navigation { }
border-color: $blue;
color: .border {
darken($blue, 9%); padding: 8px;
} margin: 8px;
border-color: #3bbfce;
.border { }
padding: $margin / 2;
margin: $margin / 2;
border-color: $blue;
}

60. table.hl { table.hl {
margin: 2em 0; margin: 2em 0;
td.ln { }
text-align: right; table.hl td.ln {
} text-align: right;
} }
li { li {
font: { font-family: serif;
family: serif; font-weight: bold;
weight: bold; font-size: 1.2em;
size: 1.2em; }
}
}

61. @mixin table-base { #data {
th { float: left;
text-align: center; margin-left: 10px;
font-weight: bold; }
} #data th {
td, th {padding: 2px} text-align: center;
} font-weight: bold;
}
@mixin left($dist) { #data td, #data th {
float: left; padding: 2px;
margin-left: $dist; }
}
#data {
@include left(10px);
@include table-base;
}

62. .error { .error, .badError {
border: 1px #f00; border: 1px #f00;
background: #fdd; background: #fdd;
} }
.error.intrusion {
.error.intrusion,
font-size: 1.3em;
.badError.intrusion
font-weight: bold;
{
}
font-size: 1.3em;
.badError { font-weight: bold;
@extend .error; }
border-width: 3px;
.badError {
}
border-width: 3px;
}

63. Always in motion the future is...

64. Rails 4.0
targeting Ruby 1.9.2
expected in an year
it will be the end of the world as we know
it :-)

65. About Bozhidar
bozhidar@empowerunited.com
http://batsov.com
@bbatsov
http://github.com/bbatsov

66. Q&A
(any questions?!)

67. Thanks!
Don’t leave just yet ;-)

68. you@empowerunited.com
facebook.com/empoweronrails