Моята презентация на тема Ruby/Rails за VarnaLab на

1. Ruby / Rails
Радослав Станков
Varna Lab 14/07/2011

2. Кой съм аз?
@rstankov
http://rstankov.com
http://blog.rstankov.com
http://github.com/rstankov

6. Ruby
Ruby е интерактивен,
обектно-ориентиран език за
програмиране.
Неготово мото е:
“Optimized for programmer happiness”

7. Ruby on Rails
Ruby on Rails е framework
за уеб приложения.
Неготово мото е:
“Web development doesn’t hurt”

8. Ruby
Създаден от японеца Юкихиро
Мацумото „Мац“.
Първата публична версия излиза
през 1995.
Версия 2.0 се очакава да излезе за
Коледа / не се казва коя /

10. class System {
// ... code ...
private $_categories = null;
public function getVisibleCategories() {
if ($this->_categories === null) {
$this->_categories = $this->findCategories(array(
'visible' => true
));
}
return $this->_categories;
}
}

11. class System
# ... code ...
def visible_categories()
return @categories ||= self.find_categories({:visible => t
end
end

12. class System
# ... code ...
def visible_categories()
return @categories ||= self.find_categories({:visible => t
end
end

13. class System
# ... code ...
def visible_categories
return @categories ||= self.find_categories({:visible => t
end
end

14. class System
# ... code ...
def visible_categories
return @categories ||= self.find_categories({:visible => t
end
end

15. class System
# ... code ...
def visible_categories
return @categories ||= self.find_categories({:visible => t
end
end

16. class System
# ... code ...
def visible_categories
@categories ||= self.find_categories({:visible => true})
end
end

17. class System
# ... code ...
def visible_categories
@categories ||= self.find_categories({:visible => true})
end
end

18. class System
# ... code ...
def visible_categories
@categories ||= self.find_categories({:visible => true})
end
end

19. class System
# ... code ...
def visible_categories
@categories ||= self.find_categories({:visible => true})
end
end

20. class System
# ... code ...
def visible_categories
@categories ||= find_categories({:visible => true})
end
end

21. class System
# ... code ...
def visible_categories
@categories ||= find_categories({:visible => true})
end
end

22. class System
# ... code ...
def visible_categories
@categories ||= find_categories :visible => true
end
end

23. 5.times { puts "Ruby is cool!" }

24. 5.times do
puts "Ruby is cool!"
end

25. File.open("some_file.txt") do |file|
file << "content"
end

26. [1,2,3,4].each { |value| puts value }
# => [1, 2, 3, 4]
[1,2,3,4].map { |value| value * value }
# => [1, 4, 9, 16]
[1,2,3,4].reduce { |a, b| a + b }
# => 10
[1,2] * 3
# => [1, 2, 1, 2, 1, 2]

27. def operate(value)
yield value
end
value = operate(5) { |v| v + 4 }
puts value # 9

28. class Person
attr_accessor :fist_name, :last_name
def initialize(first_name, last_name)
@first_name = first_name
@last_name = last_name
end
def full_name
first_name + " " + last_name
end
end
me = Person.new("Radoslav", "Stankov")
puts me.full_name # Radoslav Stankov

29. class Person
attr_accessor :fist_name, :last_name
def initialize(first_name, last_name)
@first_name = first_name
@last_name = last_name
end
def full_name
first_name + " " + last_name
end
end
me = Person.new("Radoslav", "Stankov")
puts me.full_name # Radoslav Stankov

30. class Person
attr_accessor :fist_name, :last_name
def initialize(first_name, last_name)
@first_name = first_name
@last_name = last_name
end
def full_name
first_name + " " + last_name
end
end
me = Person.new("Radoslav", "Stankov")
puts me.full_name # Radoslav Stankov

31. class Person
attr_accessor :fist_name, :last_name
def initialize(first_name, last_name)
@first_name = first_name
@last_name = last_name
end
def full_name
first_name + " " + last_name
end
end
me = Person.new("Radoslav", "Stankov")
puts me.full_name # Radoslav Stankov

32. class Person
attr_accessor :fist_name, :last_name
def initialize(first_name, last_name)
@first_name = first_name
@last_name = last_name
end
def full_name
first_name + " " + last_name
end
end
me = Person.new("Radoslav", "Stankov")
puts me.full_name # Radoslav Stankov

33. class Person
def +(other_person)
# ...
end
end
person1 + person2

34. class Array
def first
self[0]
end
def second
self[1]
end
end
array = [1, 2, 3, 4]
array.first # 1
array.second # 2

35. class Numeric
def plus(x)
self + x
end
end
y = 5.plus(6)

36. Time.now - 2.days == 2.days.ago
1.month.ago + 45.days - 1.year

37. Ruby
• димично определяне на типа данните
• модули
• отворени класове
• блокове
• анонимни функции
• всяка операция връща резултат
• всичко е изпълним код
• изчистен синтаксис
• мета програмиране
• промяна на обектите по време на изпълнение
• вградени регулярни изрази

44. Ruby on Rails
Разработен от David
Heinemeier Hansson от 37
Signals.
Първата публична версия е
излиза през юли 2004.
Вървим бавно, но сигурно
към 3.1

50. 37signals
Милиони клиенти ... по-малко от 37 служителя

56. Основни принципи на
Ruby on Rails
• Convention over Configuration
• DRY - Don’t Repeat Yourself
• KISS - Keep it simple, Stupid!
• Skinny Controller, Fat Model
• Тest Driven Development / Behavior Driven Development
• Less is More
• Code Generation
• REST

57. Основни принципи на
Ruby on Rails
• Convention over Configuration
• DRY - Don’t Repeat Yourself
• KISS - Keep it simple, Stupid!
• Skinny Controller, Fat Model
• Тest Driven Development / Behavior Driven Development
• Less is More
• Code Generation
• REST
N !
VE FU
HA

58. MVC Архитектура

59. Начин на работа

60. REST
Method Path Controller Action
GET /tasks tasks index
GET /tasks/new tasks new
POST /tasks tasks create
GET /tasks/:id tasks show
GET /tasks/:id/edit tasks edit
PUT /tasks/:id tasks update
DELETE /tasks/:id tasks delete

61. Url формати
Method Path Shows Action
GET /tasks/1 html show
GET /tasks/1.xml xml show
GET /tasks/1.json json show
GET /tasks/1.print html show
PUT /tasks/1 redirect update
PUT(xhr) /tasks/1 html/js update
PUT /tasks/1.json json update

81. Model
class Task < ActiveRecord::Base
belongs_to :user
has_many :comments
validates_presence_of :user, :text
validates_inclusion_of :status, :in => ["opened", "completed"]
attr_readonly :user_id
def editable?
status == "opened"
end
end

82. Model
class Task < ActiveRecord::Base
belongs_to :user
has_many :comments
validates_presence_of :user, :text
validates_inclusion_of :status, :in => ["opened", "completed"]
attr_readonly :user_id
def editable?
status == "opened"
end
end

83. Model
class Task < ActiveRecord::Base
belongs_to :user
has_many :comments
validates_presence_of :user, :text
validates_inclusion_of :status, :in => ["opened", "completed"]
attr_readonly :user_id
def editable?
status == "opened"
end
end

84. Model
class Task < ActiveRecord::Base
belongs_to :user
has_many :comments
validates_presence_of :user, :text
validates_inclusion_of :status, :in => ["opened", "completed"]
attr_readonly :user_id
def editable?
status == "opened"
end
end

85. Model
class Task < ActiveRecord::Base
belongs_to :user
has_many :comments
validates_presence_of :user, :text
validates_inclusion_of :status, :in => ["opened", "completed"]
attr_readonly :user_id
def editable?
status == "opened"
end
end

86. Controller
class TasksController < ApplicationController
before_filter :require_user
def index
@tasks = Task.where(:status => "opened")
end
def show
@task = Task.find(params[:id])
end
def create
@task = current_user.tasks.build(params[:task])
if @task.save
redirect_to tasks_path
else
render :partial => "new"
end
end
end

87. Controller
class TasksController < ApplicationController
before_filter :require_user
def index
@tasks = Task.where(:status => "opened")
end
def show
@task = Task.find(params[:id])
end
def create
@task = current_user.tasks.build(params[:task])
if @task.save
redirect_to tasks_path
else
render :partial => "new"
end
end
end

88. Controller
class TasksController < ApplicationController
before_filter :require_user
def index
@tasks = Task.where(:status => "opened")
end
def show
@task = Task.find(params[:id])
end
def create
@task = current_user.tasks.build(params[:task])
if @task.save
redirect_to tasks_path
else
render :partial => "new"
end
end
end

89. Controller
class TasksController < ApplicationController
before_filter :require_user
def index
@tasks = Task.where(:status => "opened")
end
def show
@task = Task.find(params[:id])
end
def create
@task = current_user.tasks.build(params[:task])
if @task.save
redirect_to tasks_path
else
render :partial => "new"
end
end
end

90. Controller
class TasksController < ApplicationController
before_filter :require_user
def index
@tasks = Task.where(:status => "opened")
end
def show
@task = Task.find(params[:id])
end
def create
@task = current_user.tasks.build(params[:task])
if @task.save
redirect_to tasks_path
else
render :partial => "new"
end
end
end

91. View
<%= form_for task do |form| %>
<%= render 'shared/error_messages', :target => form.object
%>
<p>
<%= form.label :text %>
<%= form.text_area :text %>
</p>
<p>
<%= form.label :status %>
<%= form.select :status, Task.statuses %>
</p>
<div class="buttons">
<%= form.submit %> |
<% link_to "Cancel", tasks_path %>
</div>
<% end %>

92. View + simple_form / slim
= simple_form_for task do |form|
= form.error_banner
= form.input :text
= form.input :status, :collection => Task.statuses
.buttons
= form.submit
= link_to 'Cancel', tasks_path

93. Test Driven Development

94. Test Driven Development
1 Добавя се тест
... за несъществуващ код

95. Test Driven Development
1 Добавя се тест
... за несъществуващ код
2 Пише се код
... колкото само тестът да мине

96. Test Driven Development
1 Добавя се тест
... за несъществуващ код
2 Пише се код
... колкото само тестът да мине
3 Правят се подобрения
... подобрява се качеството на кода

97. Test Driven Development
1 Добавя се тест
... за несъществуващ код
2 Пише се код
... колкото само тестът да мине
3 Правят се подобрения
... подобрява се качеството на кода

98. Cucumber feature
Feature: Tasks
In order to get more productive and organize
As a user
I want able to manage my tasks
Scenario: Adding tasks
Given I am on the tasks page
When I follow "New task"
And I fill in "Text" with "Present Ruby"
And I select "opened" from "Status"
And I press "Create task"
Then I should have opened task "Present Ruby"
Scenario: Completing tasks
Given I am on the tasks page
And I have opened task "Present Ruby"
When I follow "Edit tasks"
And I select "completed" from "Status"
And I press "Update task"
Then I should have completed task "Present Ruby"

99. Тесване на Controller
describe TasksController do
describe "GET 'show'" do
before { Task.should_recive(:find).with("1").and_return task }
before { get :show, :id => "1" }
it { should assign_to(:task).with(task) }
it { should render_temlate("show") }
end
end

100. describe Task do
it { should belong_to(:user) }
it { should have_many(:notes) }
it { should validate_presence_of(:user) }
it { should validate_presence_of(:text) }
describe "#editable?" do
it "returns true if task status is 'opened'" do
Task.new(:status => "opened").should be_editable
end
it "returns false if task status is 'rejected'" do
Task.new(:status => "rejected").should_not be_editable
end
it "returns false if task status is 'completed" do
Task.new(:status => "completed").should_not be_editable
end
end
end

101. Тестване на View
describe "tasks/show.html.erb" do
before do
assign :task, mock_model(Task, {
:id => 1,
:text => "task text"
})
render
end
it "renders task text" do
rendered.should contain("task text")
end
it "renders link for editing task" do
rendered.should have_selector('a[href="/tasks/1/edit"]')
end
end

102. ... и още, и още
• database migrations
• gem dependency management
• css/javascript management (from Rails 3.1)
• nested forms
• automatic deploys
• Rack
• generations
• send/receive mails
• caching
• internalization (i18n)
• Ruby language extentions
• a LOT plugins, tools and services
• ... и т.н.

103. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

104. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

105. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

106. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

107. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

108. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

109. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

110. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

111. Погрешни схващания
• Rails CAN'T SCALE
• Rails is SLOW!!!!
• Hard to deploy
• Too much magic
• Hard to learn every thing
• Impossible to extend rails!
• No good IDE
• Bad windows support
• Documentation

113. Благодаря за вниманието
@rstankov