Conhecendo as entranhas do Rails

Middleware Stack
Rack::Cache
ActionDispatch::SSL
Rack::Sendﬁle
ActionDispatch::Static
Rack::Lock
Rack::Runtime
Rack::MethodOverride
ActionDispatch::RequestId
Rails::Rack::Logger
ActionDispatch::ShowExceptions
ActionDispatch::DebugExceptions
ActionDispatch::RemoteIp
ActionDispatch::Reloader
ActionDispatch::Callbacks
ActionDispatch::Cookies
ActionDispatch::Session::CookieStore
ActionDispatch::Flash
ActionDispatch::ParamsParser
Rack::Head
Rack::ConditionalGet
Rack::ETag
ActionDispatch::BestStandardsSupport
Rails

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Middleware Stack
Rack::Cache
ActionDispatch::SSL
Rack::Sendﬁle
ActionDispatch::Static
Rack::Lock
Rack::Runtime
Rack::MethodOverride
ActionDispatch::RequestId
Rails::Rack::Logger
ActionDispatch::ShowExceptions
ActionDispatch::DebugExceptions
ActionDispatch::RemoteIp
ActionDispatch::Reloader
ActionDispatch::Callbacks
ActionDispatch::Cookies
ActionDispatch::Session::CookieStore
ActionDispatch::Flash
ActionDispatch::ParamsParser
Rack::Head
Rack::ConditionalGet
Rack::ETag
ActionDispatch::BestStandardsSupport
rails-api

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rails-api
$ rails new normal_application
$ cd normal_application
$ rake middleware RAILS_ENV=production | wc -l
$ rails-api new api_application
$ cd api_application
$ rake middleware RAILS_ENV=production | wc -l
22
17

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Processo de
inicialização

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Rails::Railtie
Rails::Engine
Rails::Application

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Rails::Railtie
# railties/lib/rails/all.rb
require "rails"
%w(
active_record
action_controller
action_mailer
rails/test_unit
sprockets/rails
).each do |framework|
begin
require "#{framework}/railtie"
rescue LoadError
end
end

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module ActiveRecord
class Railtie < Rails::Railtie
config.active_record = ActiveSupport::OrderedOptions.new
config.app_generators.orm :active_record, :migration => true,
:timestamps => true
config.app_middleware.insert_after "::ActionDispatch::Callbacks",
"ActiveRecord::QueryCache"
# ...
config.action_dispatch.rescue_responses.merge!(
'ActiveRecord::RecordNotFound' => :not_found,
'ActiveRecord::StaleObjectError' => :conflict,
'ActiveRecord::RecordInvalid' => :unprocessable_entity,
'ActiveRecord::RecordNotSaved' => :unprocessable_entity
)
rake_tasks do
# ...
end
console do |app|
# ...
end
end
end
Rails::Railtie

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module ActiveRecord
:timestamps => true
# ...
end
end
Rails::Railtie

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module ActiveRecord
:timestamps => true
# ...
end
end
Rails::Railtie

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module ActiveRecord
:timestamps => true
# ...
end
end
Rails::Railtie

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module ActiveRecord
# ...
config.action_dispatch.rescue_responses.merge!(
'ActiveRecord::RecordNotFound' => :not_found,
'ActiveRecord::StaleObjectError' => :conflict,
'ActiveRecord::RecordInvalid' => :unprocessable_entity,
'ActiveRecord::RecordNotSaved' => :unprocessable_entity
)
# ...
end
end
Rails::Railtie

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module ActiveRecord
# ...
rake_tasks do
# ...
end
console do |app|
# ...
end
end
end
Rails::Railtie

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Rails::Railtie
Rails::Engine
Rails::Application

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Rails::Engine
module Devise
class Engine < ::Rails::Engine
config.app_middleware.use Warden::Manager do |config|
Devise.warden_config = config
end
config.before_eager_load { |app| app.reload_routes! }
initializer "devise.url_helpers" do
# ...
end
initializer "devise.omniauth" do |app|
# ...
end
end
end
https://github.com/plataformatec/devise

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Rails::Engine
module Devise
end
# ...
end
# ...
end
end
end

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Rails::Engine
module Devise
end
# ...
end
# ...
end
end
end

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Rails::Engine
module Devise
end
# ...
end
# ...
end
end
end

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module MyEngine
class Engine < Rails::Engine
endpoint MyRackApplication
end
end
Rails::Engine

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Mountable Engines
# ENGINE/config/routes.rb
MyBlogEngine::Engine.routes.draw do
resources :posts do
resources :comments
end
end
MyRailsApp::Application.routes.draw do
mount MyBlogEngine::Engine => "/blog"
end

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Isolated Engines
module MyBlog
end
end
MyBlog::Engine.routes.draw do
resources :posts
end
MyRailsApp::Application.routes.draw do
resources :posts
mount MyBlog::Engine => "/blog"
end
posts_path # => PostsController#index

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Isolated Engines
module MyBlog
isolate_namespace MyBlog
end
end
MyBlog::Engine.routes.draw do
resources :posts
end
posts_path # => MyBlog::PostsController#index

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Isolated Engines
# config/routes.rb
MyApplication::Application.routes.draw do
mount MyBlog::Engine => "/blog", :as => "my_blog"
get "/foo" => "foo#index"
end

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Isolated Engines
# config/routes.rb
MyApplication::Application.routes.draw do
mount MyBlog::Engine => "/blog", :as => "my_blog"
get "/foo" => "foo#index"
end

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Isolated Engines
class FooController < ApplicationController
def index
my_blog.root_url #=> /blog/
end
end

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Isolated Engines
module MyEngine
class BarController
def index
main_app.foo_path #=> /foo
end
end
end

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Rails::Railtie
Rails::Engine
Rails::Application

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Rails::Application
module MyProject
class Application < Rails::Application
config.i18n.default_locale = "pt-BR"
config.encoding = "utf-8"
config.filter_parameters += [:password]
config.generators do |g|
g.orm :mongoid
g.test_framework :rspec
g.stylesheets false
end
end
end

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Rails::Application
module MyProject
g.orm :mongoid
g.stylesheets false
end
end
end

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Rails::Application
module MyProject
g.orm :mongoid
g.stylesheets false
end
end
end

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Rails::Application
module MyProject
g.orm :mongoid
g.stylesheets false
end
end
end

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ActionController
::Metal

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AbstractController::Base
ActionController::Metal
ActionController::Base
ActionMailer::Base

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ActionController::Metal
class HelloController < ActionController::Metal
include ActionController::Rendering
append_view_path "#{Rails.root}/app/views"
def index
render "hello/index"
end
end

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ActionController::API
ActionController::UrlFor
ActionController::Redirecting
ActionController::Rendering
ActionController::Renderers::All
ActionController::ConditionalGet
ActionController::ForceSSL
ActionController::RackDelegation
ActionController::DataStreaming
AbstractController::Callbacks
ActionController::Instrumentation
ActionController::Rescue
ActionController::HideActions
https://github.com/rails/rails/blob/c0b69630/
actionpack/lib/action_controller/base.rb#L183-225

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Processo de inicialização
Middleware Stack
Controllers

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https://github.com/rails/rails/commit/
6db930cb5bbff9ad824590b5844e04768de240b1

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Precisamos
provasde

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Assíncronos
Mailers

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class UsersController < ActionController::Base
def create
@user = User.new params[:user]
if @user.save
UserMailer.deliver_welcome_email @user
end
respond_with @user
end
end
Rails 3

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Criar usuário

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Criar usuário
Enviar Email

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Criar usuário
Enviar Email
Renderizar View

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Criar usuário

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Criar usuário
Enviar Email
Renderizar View

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def create
if @user.save
end
respond_with @user
end
end
Rails 3

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def create
if @user.save
end
respond_with @user
end
end
Rails 4

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# app/mailers/user_mailer.rb
class UserMailer < ActionMailer::Base
self.async = true
def welcome_email
# ...
end
end
Rails 4

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# app/mailers/user_mailer.rb
class UserMailer < ActionMailer::Base
self.async = true
def welcome_email
# ...
end
end
Rails 4

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# config/application.rb
config.action_mailer.async = true
Rails 4

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API
Queue

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Sidekiq
STDlib Queue
Resque
DelayedJob

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Queue API
Rails.queue.push SomeJob.new
job = Rails.queue.pop
job.run

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# config/application.rb
config.queue = Rails::Queueing::Queue
Rails.queue[:mail_queue] = SomeQueue.new

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Notificações
Sistema de

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class ExplainSubscriber # :nodoc:
def start(name, id, payload)
# unused
end
def finish(name, id, payload)
if queries = Thread.current[:queries]
unless ignore_payload?(payload)
queries << payload.values_at(:sql, :binds)
end
end
end
ActiveSupport::Notifications.
subscribe("sql.active_record", new)
end

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# unused
end
end
end
end
end

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# unused
end
end
end
end
end

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# unused
end
end
end
end
end

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def log(sql, name = "SQL", binds = [])
@instrumenter.instrument(
"sql.active_record",
:sql => sql,
:name => name,
:connection_id => object_id,
:binds => binds) { yield }
# ...
end
log(sql, name) { @connection.execute(sql) }

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:sql => sql,
:name => name,
# ...
end

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:sql => sql,
:name => name,
# ...
end

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:sql => sql,
:name => name,
# ...
end

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:sql => sql,
:name => name,
# ...
end

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def logging_query_plan
# ...
begin
queries = current[:queries] = []
start = Time.now
result = yield
if Time.now - start > threshold
logger.warn(exec_explain(queries))
end
result
ensure
current[:queries] = nil
end
end

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# ...
begin
start = Time.now
result = yield
end
result
ensure
end
end

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# ...
begin
start = Time.now
result = yield
end
result
ensure
end
end

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# ...
begin
start = Time.now
result = yield
end
result
ensure
end
end

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# unused
end
end
end
end
end

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# unused
end
end
end
end
end

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# unused
end
end
end
end
end

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logging_query_plan { User.joins(:comments).to_a }

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Features
Outras

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Routing
Concerns

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# config/routes.rb
MyApp::Application.routes.draw do
resources :messages { resources :comments }
resources :forwards { resources :comments }
resources :uploads { resources :comments }
resources :documents { resources :comments }
resources :todos { resources :comments }
end

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# config/routes.rb
resources :messages { resources :comments }
resources :forwards { resources :comments }
resources :uploads { resources :comments }
resources :documents { resources :comments }
resources :todos { resources :comments }
end

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# config/routes.rb
concerns :commentable do
resources :comments
end
resources :messages, :forwards, :uploads,
:documents, :todos,
:concerns => :commentable
end

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# config/routes.rb
resources :comments
end
:documents, :todos,
end

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# config/routes.rb
resources :comments
end
:documents, :todos,
end

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# config/routes.rb
resources :comments
end
:documents, :todos,
end

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Parameters
Strong

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class PeopleController < ApplicationController
def create
person = Person.create(params[:person])
respond_with person
end
end
class Person < ActiveRecord::Base
attr_accessible :name, :age
end
Rails 3

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def create
respond_with person
end
end
end
Rails 3

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def create
respond_with person
end
end
end
Rails 3

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def create
respond_with person
end
end
end
Rails 3

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class Person
include ActiveRecord::Model
end
def create
# BOOM!!!!
respond_with person
end
end
Rails 4

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class Person
end
def create
# BOOM!!!!
respond_with person
end
end
Rails 4

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class Person
end
def create
# BOOM!!!!
respond_with person
end
end
Rails 4

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class Person
end
def create
# BOOM!!!!
respond_with person
end
end
Rails 4

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def update
person = Person.find(params[:id])
person.update_attributes(person_params)
respond_with person
end
private
def person_params
params.require(:person).permit(:name, :age)
end
end
Rails 4

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def update
respond_with person
end
private
def person_params
end
end
Rails 4

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def update
respond_with person
end
private
def person_params
end
end
Rails 4

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def update
respond_with person
end
private
def person_params
end
end
Rails 4

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def update
respond_with person
end
private
def person_params
end
end
Rails 4

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JSON

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class PostsController < ApplicationController
def show
@post = Post.find(params[:id])
render :json => post_json
end
private
def post_json
@post.as_json(:only => [:id, :title, :body],
:include => { :comments =>
{ :only => [:id, :body] } }
)
end
end

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def show
end
private
def post_json
{ :only => [:id, :body] } }
)
end
end

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def show
end
private
def post_json
{ :only => [:id, :body] } }
)
end
end

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def show
end
private
def post_json
{ :only => [:id, :body] } }
)
end
end

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def show
end
private
def post_json
{ :only => [:id, :body] } }
)
end
end

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def show
end
private
def post_json
{ :only => [:id, :body] } }
)
end
end

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ActiveModel
::Serializers
https://github.com/josevalim/active_model_serializers

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def show
render :json => @post
end
end
# app/serializers/post_serializer.rb
class PostSerializer < ActiveModel::Serializer
embed :ids, :include => true
attributes :id, :title, :body
has_many :comments
end

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