Rails 3 - RS on Rails - 21aug2010

Rails 3

Carlos Antonio blog.plataformatec.com.br @cantoniodasilva

Rails 3

ID blog twitter


Quem sou eu?

• Carlos Antonio da Silva

• Desenvolvedor Ruby e Rails há mais de 2 anos

• Engenheiro da Plataforma Tecnologia a 1 ano


Desenvolvimento de
aplicações em Rails

Coaching em Consultoria
Rails e Agile


Como tudo começou?


Vantagens do Rails 3



Performance



Modularidade

Performance



Agnosticismo

Modularidade

Performance


Arquitetura

Rails

ActionDispatch

ActiveSupport


Arquitetura
Todo o resto são
Railties!
Rails

ActionDispatch

ActiveSupport


Arquitetura
Todo o resto são
Railties!
ActiveRecord
Rails
ActionView
ActionDispatch

outros... ActiveSupport

ActionController

ActionMailer


Como o Rails 3
muda o modo como
desenvolvemos?


rails command
Rails 2.3 Rails 3

rails blog rails new blog


rails command
Rails 2.3 Rails 3
ruby script/server rails server
ruby script/console rails console
ruby script/generate rails generate
ruby script/dbconsole rails dbconsole


rails command
Rails 3 Shortcuts!
rails server rails s
rails console rails c
rails generate rails g
rails dbconsole rails db


blog/conﬁg.ru

require ::File.expand_path('../config/environment', __FILE__)
run Blog::Application


blog/conﬁg/application.rb
require File.expand_path('../boot', __FILE__)
require 'rails/all'

Bundler.require(:default, Rails.env) if defined?(Bundler)

module Blog
class Application < Rails::Application
config.encoding = "utf-8"
config.filter_parameters += [:password]
end
end


blog/conﬁg/application.rb
require File.expand_path('../boot', __FILE__)
require 'rails/all'

Bundler.require(:default, Rails.env) if defined?(Bundler)

module Blog uma Rack App!
class Application < Rails::Application
config.encoding = "utf-8"
config.filter_parameters += [:password]
end
end


O que é uma Rack App?


O que é uma Rack App?

Qualquer objeto que responde ao método call,
retornando um array com três parâmetros: o
response status, os headers e o body, que por
sua vez deve responder ao método each.
Rack App!
lambda { |env| [ 200, {“Content-Type” => “plain/text”}, ["Hello!"] ] }


blog/conﬁg/boot.rb
require 'rubygems'

# Set up gems listed in the Gemfile.
gemfile = File.expand_path('../../Gemfile', __FILE__)
begin
ENV['BUNDLE_GEMFILE'] = gemfile
require 'bundler'
Bundler.setup
rescue Bundler::GemNotFound => e
STDERR.puts e.message
STDERR.puts "Try running `bundle install`."
exit!
end if File.exist?(gemfile)


Bundler
Router
ActionMailer
ActiveModel
ActiveRecord
Responders
Unobtrusive Javascript
XSS Protection


Biblioteca para gerenciamento de
dependências


Rubygems
Resolução de dependências
rsrails$ gem dependency actionpack -v="2.3.5"
Gem actionpack-2.3.5
activesupport (= 2.3.5, runtime)
rack (~> 1.0.0, runtime)

rsrails$ gem dependency thin
Gem thin-1.2.7
daemons (>= 1.0.9, runtime)
eventmachine (>= 0.12.6, runtime)
rack (>= 1.0.0, runtime)


Rubygems
Gems instaladas do rack: require "rubygems"
* rack (1.0.1) require "thin"
* rack (1.1.0) gem "actionpack", "2.3.5"


Rubygems

BOOM!!!


Rubygems

can't activate rack (~> 1.0.0, runtime) for
["actionpack-2.3.5"], already activated rack-1.1.0 for
["thin-1.2.7"] (Gem::LoadError)


Bundler: Gemﬁle
# Gemfile
gem "thin"
gem "actionpack", "2.3.5"


Bundler: Gemﬁle
# Gemfile
gem "thin"
gem "actionpack", "2.3.5"

rsrails$ bundle list
Gems included by the bundle:
* actionpack (2.3.5)
* activesupport (2.3.5)
* daemons (1.0.10)
* eventmachine (0.12.10)
* rack (1.0.1)
* thin (1.2.7)


Rubygems
$LOAD_PATH


}
rsrails$ gem list
*** LOCAL GEMS ***

bundler (0.9.25)
rake (0.8.7, 0.8.5)
Filesystem
rdoc (2.5.8)
thor (0.13.6)


}
rsrails$ gem list
*** LOCAL GEMS ***

bundler (0.9.25)
rake (0.8.7, 0.8.5)
Filesystem
rdoc (2.5.8)
thor (0.13.6)

# Rubygems
gem “rake”, “0.8.5”
} Gemﬁle


}
rsrails$ gem list
*** LOCAL GEMS ***

bundler (0.9.25)
rake (0.8.7, 0.8.5)
Filesystem
rdoc (2.5.8)
thor (0.13.6)

# Rubygems
gem “rake”, “0.8.5”
} Gemﬁle

}
bundler (0.9.25)
rake (0.8.7, 0.8.5) $LOAD_PATH
rdoc (2.5.8)
thor (0.13.6)


Bundler
Lock no $LOAD_PATH


Esqueci de colocar no conﬁg.gem!


}
rsrails$ gem list
*** LOCAL GEMS ***

bundler (0.9.25)
rake (0.8.7, 0.8.5)
Filesystem
rdoc (2.5.8)
thor (0.13.6)

# Gemfile - Bundler
gem “rake”, “0.8.5”
} Gemﬁle


}
rsrails$ gem list
*** LOCAL GEMS ***

bundler (0.9.25)
rake (0.8.7, 0.8.5)
Filesystem
rdoc (2.5.8)
thor (0.13.6)

# Gemfile - Bundler
gem “rake”, “0.8.5”
} Gemﬁle

rake-0.8.5
} $LOAD_PATH


rsrails$ gem list
rake (0.8.7, 0.8.5)
thor (0.13.6)


rsrails$ gem list
rake (0.8.7, 0.8.5)
thor (0.13.6)

# Gemfile
gem "rake"


rsrails$ gem list
rake (0.8.7, 0.8.5)
thor (0.13.6)

# Gemfile
gem "rake"

# test_load_path_lock.rb
require "rubygems"
require "bundler"
Bundler.setup
require "rake"
require "thor"


rsrails$ gem list
rake (0.8.7, 0.8.5)
thor (0.13.6)

# Gemfile
gem "rake"

require "rubygems"
require "bundler"
Bundler.setup Lock no $LOAD_PATH
require "rake"
require "thor"


rsrails$ gem list
rake (0.8.7, 0.8.5)
thor (0.13.6)

# Gemfile
gem "rake"

require "rubygems"
require "bundler"
Bundler.setup Lock no $LOAD_PATH
require "rake"
require "thor"

rsrails$ ruby test_load_path_lock.rb
test_load_path_lock.rb:6:in `require': no such ﬁle to load -- thor (LoadError)

from test_load_path_lock.rb:6


Packaging System
OMG!


Router
Nova API


Rotas root
Rails 2.3

map.root :controller => "welcome"

Rails 3
root :to => "welcome#index"


Rotas comuns
Rails 2.3

map.connect "products/:id", :controller=> "catalog", :action => "view"

Rails 3
match 'products/:id' => 'catalog#view'


Rotas nomeadas
Rails 2.3
map.purchase "products/:id/purchase", :controller => "catalog",
:action => "purchase"

Rails 3
match "products/:id/purchase" => 'catalog#purchase',
:as => :purchase


Resources com member e
collection
Rails 2.3

map.resources :products, :member => { :short => :get,
:toggle => :post }, :collection => { :sold => :get }

Rails 3 resources :products do
member do
get :short
post :toggle
end

get :sold, :on => :collection
end


Router e Rack FTW!


Router e Rack FTW!
match "posts/:echo", :to => "posts#show"


Router e Rack FTW!

Rack App!
match "posts/:echo", :to => PostsController.action(:show)


Router e Rack FTW!


Rack App!
match "/posts/:echo" => redirect("/foo/%{echo}")


Router e Rack FTW!



Rack App!
match "posts/:echo" => lambda { |env| [ 200, {“Content-Type” =>
“plain/text”}, ["Echo!"] ] }


Router e Rack FTW!



match "posts/:echo" => lambda { |env| [ 200, {“Content-Type” =>
“plain/text”}, ["Echo!"] ] }

Rack App!
match "posts/:echo" => MySinatraBlog


100% compatível
com Rack
OMG!


ActionMailer
rsrails$ ls -lp app/
controllers/
helpers/
mailers/
models/
views/

rsrails$ rails g mailer Notifier signup_notification
create app/mailers/notifier.rb
invoke erb
create app/views/notifier
create app/views/notifier/signup_notification.text.erb
invoke test_unit
create test/functional/notifier_test.rb


ActionMailer
rsrails$ ls -lp app/
controllers/
helpers/
mailers com diretório próprio
mailers/
models/
views/

rsrails$ rails g mailer Notifier signup_notification
create app/mailers/notifier.rb
invoke erb
create app/views/notifier
create app/views/notifier/signup_notification.text.erb
invoke test_unit
create test/functional/notifier_test.rb


ActionMailer
Nova API


TMail


TMail

Mail


ActionMailer nova API
class Notifier < ActionMailer::Base
default :from => "system@example.com"

def signup_notification(recipient)
@account = recipient
attachments['image.jpg'] = File.read("image.jpg")
mail(:to => recipient.email) do |format|
format.html
format.text
end
end
end


class Notifier < ActionMailer::Base Defaults
default :from => "system@example.com"

def signup_notification(recipient)
format.html
format.text
end
end
end


Variáveis default :from => "system@example.com"
de
instância def signup_notification(recipient)
format.html
format.text
end
end
end


de
instância def signup_notification(recipient) Attachments tipo
@account = recipient cookies
format.html
format.text
end
end
end


de
instância def signup_notification(recipient) Attachments tipo
@account = recipient cookies
format.html
format.text
end
end mail tipo respond_to do |format|
end


AbstractController::Base

ActionController::Metal

ActionMailer::Base ActionController::Base


Menos coisas para
lembrar
OMG!


ActiveModel


ActiveModel
• Google Summer of Code 2009:


ActiveModel

• Extrair a lógica comum entre ActiveRecord e
ActiveResource


ActiveModel

ActiveResource

• Hoje


ActiveModel

ActiveResource

• Hoje

• Desempenha papel no agnosticismo de ORM


ActiveModel

ActiveResource

• Hoje

• Desempenha papel no agnosticismo de ORM

• Permite a criação de models à la ActiveRecord


ActiveResource::Base +
ActiveModel
module ActiveResource
...
class Base
extend ActiveModel::Naming
include CustomMethods, Observing, Validations
include ActiveModel::Conversion
include ActiveModel::Serializers::JSON
include ActiveModel::Serializers::Xml
end
end


ActiveRecord::Base +
ActiveModel
Base.class_eval do
...
extend ActiveModel::Naming
...
include ActiveModel::Conversion
include Validations
...
include ActiveModel::MassAssignmentSecurity
include Callbacks, ActiveModel::Observing, Timestamp
end
end


MyApp + ActiveModel
class Person
include ActiveModel::Validations

attr_accessor :name, :age
validates_presence_of :name, :age
end

>> p = Person.new
=> #<Person:0x102623588>
>> p.valid?
=> false
>> p.errors.full_messages
=> ["Name can't be blank", "Age can't be blank"]


Agnosticismo de ORM


Agnosticismo de ORM

Agnosticismo de ORM

ActiveModel Rails::Railtie


Agnosticismo de ORM

Agnosticismo de ORM


Provê uma API para que o
ActionPack possa conversar com o
ORM


Agnosticismo de ORM

Agnosticismo de ORM


Provê uma API para que o
Integração do ORM com o Rails
ActionPack possa conversar com o
ORM


ActiveModel
Validations

Callbacks

Serialization

ActiveRecord Data Mapper MongoDB MeuModel


ActiveModel::Lint::Tests


module ActiveModel
module Lint
module Tests

def test_to_key; end
def test_to_param; end
def test_valid?; end
def test_persisted?; end
def test_model_naming; end
def test_errors_aref; end
def test_errors_full_messages; end

end
end
end


ActiveRecord-like
Ótimo exemplo de uso do ActiveModel

http://github.com/plataformatec/mail_form


Menos hacks!
Reusabilidade
OMG!


Nova API

select joins
where includes
order group
limit having
offset lock
from readonly


Nova API
Rails 2.3

Post.find(:all, :order => "published_at desc", :limit => 10)

Rails 3

Post.order("published_at desc").limit(10)


Nova API
Rails 2.3
Post.all(:conditions => ["published_at <= ?", Time.now],
:include => :comments)

Rails 3

Post.where("published_at <= ?", Time.now).includes(:comments)


Lazy loading
Rails 2.3
Job.find(:all, :conditions => {:published => true})

Faz um query no DB imediatamente e retorna um array de Jobs

Rails 3
Job.where(:published => true)

Não faz query no DB, retorna um ActiveRecord::Relation


Lazy loading
# app/controllers/jobs_controller.rb
class JobsController < ApplicationController
def index
@jobs = Jobs.where(:published => true).order("created_at DESC")
end
end

# app/views/jobs/index.html.erb
<% cache do %>
<% @jobs.each do |job| %>
...
<% end %>
<% end %>


Lazy loading
def index
end
end
Não realiza query no DB

<% cache do %>
...
<% end %>
<% end %>


Lazy loading
def index
end
end

<% cache do %>
...
<% end %>
<% end %>
Só aqui que será feito a query no DB


Lazy loading
def index
end
end

<% cache do %>
Se estiver cacheado, a query
não é disparada!
...
<% end %>
<% end %>
Só aqui que será feito a query no DB


Chainability:
it “quacks” like named_scope

cars = Car.where(:colour => 'black')
black_fancy_cars = cars.order('cars.price DESC').limit(10)
black_cheap_cart = cars.order('cars.price ASC').limit(10)


Chainability:

ActiveRecord::Relation



Chainability:

ActiveRecord::Relation


Reaproveitar uma Relation
e encadear mais ﬁnders


Falando em named_scope...
class Post < ActiveRecord::Base
has_many :comments

scope :published, where('posts.published_at is not null')
scope :recent, published.order("posts.published_at desc").limit(10)
end

class Comment < ActiveRecord::Base
belongs_to :post

scope :from_published_posts, joins(:post) & Post.published
end


Falando em named_scope...
class Post < ActiveRecord::Base
has_many :comments

scope :published, where('posts.published_at is not null')
scope :recent, published.order("posts.published_at desc").limit(10)
end

class Comment < ActiveRecord::Base DRY
belongs_to :post

scope :from_published_posts, joins(:post) & Post.published
end


Mas e sobre o ARel
que tanto se fala?


ARel == Relational Algebra
ARel != ActiveRecord::Relation


Código mais limpo
OMG!


Rails 2.3

def index
@users = User.all
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => @users }
end
end


Rails 3.0

respond_to :html, :xml

def index
@users = User.all
respond_with(@users)
end


3 variáveis

Formato do request

Verbo HTTP

Status do recurso


Rails 2.3
def create
@user = User.new(params[:user])
respond_to do |format|
if @user.save
format.html { redirect_to @user, :notice => 'User was
successfully created' }
format.xml { render :xml => @user, :status
=> :created, :location => @user }
else
format.html { render :action => "new" }
format.xml { render :xml => @user.errors, :status
=> :unprocessable_entity }
end
end
end


Rails 3.0

def create
@user = User.new(params[:user])
flash[:notice] = 'User was successfully created' if @user.save
respond_with(@user)
end



ActionController::Responder

Formato do request
Verbo HTTP
Status do recurso


ActionController::Responder

to_code

Formato do request
Verbo HTTP
Status do recurso

Responders Customizados


github.com/plataformatec/responders



FlashResponder: seta o ﬂash baseado no controller,
na action e no status do recurso




HttpCacheResponder: adiciona o cabeçalho HTTP
Last-Modiﬁed para requests de API




HttpCacheResponder: adiciona o cabeçalho HTTP
Last-Modiﬁed para requests de API

CollectionResponder: altera o redirecionamento
para a action :index ao criar/atualizar um recurso


DRY
OMG!


Unobtrusive Javascript: Rails 2.3
remote_form_for(@post)

link_to 'Destroy', post, :confirm => 'Are you sure?',:method => :delete


<form action="/posts" class="new_post" id="new_post" method="post"
onsubmit="new Ajax.Request('/posts', {asynchronous:true, evalScripts:true,
parameters:Form.serialize(this)}); return false;">

<a href="/posts/1" onclick="if (confirm('Are you sure?')) { var f = document.createElement('form');
f.style.display = 'none'; this.parentNode.appendChild(f); f.method = 'POST'; f.action = this.href;var m =
document.createElement('input'); m.setAttribute('type', 'hidden'); m.setAttribute('name', '_method');
m.setAttribute('value', 'delete'); f.appendChild(m);var s = document.createElement('input');
s.setAttribute('type', 'hidden'); s.setAttribute('name', 'authenticity_token'); s.setAttribute('value',
'LM2fEF6HuRWdYUZdEumWlemhI6iDPH97pqWhO4jEpiU='); f.appendChild(s);f.submit(); };return false;">Destroy</a>


Unobtrusive Javascript: Rails 3

form_for(@posts, :remote => true)

<form action="/posts" class="new_post" data-remote="true" id="new_post"
method="post">


Unobtrusive Javascript: Rails 3

link_to 'Destroy', post, :confirm => 'Are you sure?', :method => :delete

<a href="/posts/1" data-confirm="Are you sure?" data-method="delete"
rel="nofollow">Destroy</a>


JS para todos os gostos
• Prototype: default

• jQuery: http://github.com/rails/jquery-ujs

• MooTools: http://mootools.net/forge/p/rails_3_driver

• Você pode fazer o seu!


Javascript no Rails 3


Javascript no Rails 3

Agnosticismo de Javascript

HTML 5 custom data attributes JS driver para cada framework


Helpers Deprecados no Rails 3
• link_to_remote
• observe_ﬁeld
• form_remote_tag
• submit_to_remote
• periodically_call_remote
• remote_form_for
• observe_form
• button_to_remote

http://github.com/rails/prototype_legacy_helper


Agnosticismo +
HTML 5
OMG! JQUERY!


XSS protection
Rails 2.3: unsafe por default
<%= @job.title %> <%= h @job.title %>

unsafe safe

Rails 3: safe por default
<%= @job.title %> <%= raw @job.title %>

safe unsafe


Helpers que retornam HTML
module ApplicationHelper
def strong(content)
"<strong>#{h content}</strong>".html_safe
end
end


def strong(content)
end
end

Dicas:
1. Certiﬁcar-se de que todo input está sendo escapado


def strong(content)
end
end

Dicas:
1. Certiﬁcar-se de que todo input está sendo escapado
2. Chamar html_safe no output


Segurança
OMG!


Agora... como eu começo
a usar tudo isso que está
disponível no Rails 3?


Para começar

rsrails$ gem install rails --pre

...
Successfully installed rails-3.0.0.rc
23 gems installed

rsrails$ rails -v
Rails 3.0.0.rc


Para atualizar


Para atualizar
• rails upgrade plugin:
• http://github.com/rails/rails_upgrade


Para atualizar

• rails upgrade handbook:
• http://www.railsupgradehandbook.com/


Para atualizar

• rails upgrade handbook:
• http://www.railsupgradehandbook.com/

• screencasts “Upgrading to Rails 3”:
• http://railscasts.com/, Episódios #225, #226 e #227


?! Tem muito mais aqui!

http://github.com/plataformatec


?! Tem muito mais aqui!

http://github.com/plataformatec

ID blog twitter


Rails 3 - RS on Rails - 21aug2010

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