THE PATTERNS FALACY! Luciano Sousa http://lucianosousa.net twitter: @lucianosousa github: lucianosousa Rails Version <3 Monday, May 27, 13 

#WHOAMI? Monday, May 27, 13 

Monday, May 27, 13 

#War Feelings Monday, May 27, 13 

Focus on ideas, not examples Thing about what you are you doing with your apps Try solve your problems out of the box Monday, May 27, 13 

A BRIEF HISTORY OF TIME Monday, May 27, 13 

Monday, May 27, 13 

MVC Monday, May 27, 13 

RAILS Monday, May 27, 13 

MVC FRAMEWORK BASED RAILS Monday, May 27, 13 

MVC Definition Model–view–controller (MVC) is a software architecture pattern which separates the representation of information from the user's interaction with it. (...) • A controller can send commands to its associated view to change the view's presentation of the model (e.g., by scrolling through a document). It can also send commands to the model to update the model's state (e.g., editing a document). • A model notifies its associated views and controllers when there has been a change in its state. This notification allows the views to produce updated output, and the controllers to change the available set of commands (...). • A view requests from the model the information that it needs to generate an output representation to the user. http://en.wikipedia.org/wiki/Model-view-controller Monday, May 27, 13 

Monday, May 27, 13 

LIVE EXAMPLE Monday, May 27, 13 

‘PATTERNS’ Monday, May 27, 13 

Oh, wait... Patterns? Monday, May 27, 13 

like... Monday, May 27, 13 

OBSERVERS??? Monday, May 27, 13 

https://blog.engineyard.com/2013/rails-4-changes http://ruby5.envylabs.com/episodes/331-episode-327- december-4-2012/stories/2882-observers-and-sweepers-were- removed-from-rails http://samuelmullen.com/2013/05/the-problem-with-rails-callbacks/ Observers Monday, May 27, 13 

SCAFFOLD Monday, May 27, 13 

Sloth Monday, May 27, 13 

and... not least Monday, May 27, 13 

CoffeeScript Monday, May 27, 13 

Bad, bad server. No Donut for you Monday, May 27, 13 

TestUnit x RSpec Monday, May 27, 13 

Bad, bad server. No Donut for you Monday, May 27, 13 

Rails ‘Best’ Practices :%s/Rails/Basecamp/g Monday, May 27, 13 

LET’S PRACTICE Monday, May 27, 13 

MODELS Monday, May 27, 13 

class User < ActiveRecord::Base has_many :posts def post_titles posts.map(&:title).join(', ') end end class Post < ActiveRecord::Base belongs_to :user end Monday, May 27, 13 

config/application.rb class Application < Rails::Application config.autoload_paths += %W(#{config.root}/app/ extensions/) end Monday, May 27, 13 

module PostsExtensions def post_titles names = posts.map(&:title) names.join(‘, ‘) end end class User < ActiveRecord::Base include PostsExtensions has_many :posts end Monday, May 27, 13 

Rails 4 - Concerns Monday, May 27, 13 

‘Concerned’ people prefer a different name!!! Monday, May 27, 13 

Please Monday, May 27, 13 

Controllers Monday, May 27, 13 

class UsersController < ApplicationController def index @users = search_users end private def search_users filters = [] unless params[:name].blank? filters << [ “name = ?”, params[:name] end unless params.[:last_name].blank? filters << [ “last_name = ?”, params[: last_name] end . . . User.where(filters) end end Monday, May 27, 13 

config/application.rb class Application < Rails::Application config.autoload_paths += %W(#{config.root}/app/extensions/ #{config.root}/lib/ ) end Monday, May 27, 13 

module UsersSearch def search_users filters = [] unless params[:name].blank? filters << [ “name = ?”, params[:name] end unless params.[:last_name].blank? filters << [ “last_name = ?”, params[: last_name] end . . . User.where(filters) end end Monday, May 27, 13 

class UsersController < ApplicationController include UsersSearch def index @users = search_users end end Monday, May 27, 13 

VIEWS Monday, May 27, 13 

Avoid if’s Monday, May 27, 13 

DECORATOR Monday, May 27, 13 

class PostsList def initialize(posts, user) @posts = posts @user = user end def build_posts posts_list = [] @posts do |post| posts_list << OpenStruct.new( title: post.title, description: post.description ? post.description : ‘Sorry. No text here!’, author_name: @user.full_name ) end posts_list end Monday, May 27, 13 

<% @posts.each do |post| %> <%= post.title %> <%= post. description %> <%= post.author_name %> <% end %> Monday, May 27, 13 

Monday, May 27, 13 

OH, WAIT!!!! Monday, May 27, 13 

class User < ActiveRecord::Base include PostsExtensions include AvatarsExtensions include PaymentsExtensions include include include include include include include . . . end Monday, May 27, 13 

Editor’s problem Monday, May 27, 13 

Monday, May 27, 13 

module UsersExtensions def users users.map(&:name) end end Monday, May 27, 13 

module UsersExtensions def users users.map(&:name) end end Monday, May 27, 13 

class Registrations < ActiveRecord::Base include UsersExtensions has_many :users end > r = Registration.first > r.users => [ ‘you’, ‘are dumb’] Monday, May 27, 13 

Developer’s problem Monday, May 27, 13 

Monday, May 27, 13 

module UsersExtensions def users_name users.map(&:name) end end Monday, May 27, 13 

Monday, May 27, 13 

sum = any_hash.map { |k, v| k + v * 10 } Monday, May 27, 13 

sum = any_hash.map { |discount, price| discount + price * TAX } Monday, May 27, 13 

Monday, May 27, 13 

Bonus Monday, May 27, 13 

Just an example (another terrible one)... Monday, May 27, 13 

require 'spec_helper' describe User do it 'testing create user time' do 100.times { user = FactoryGirl.create(:user) user.should_not be_nil } end end Monday, May 27, 13 

$ time rspec spec/models/user_spec.rb . Finished in 6.67 seconds 1 example, 0 failures Monday, May 27, 13 

require 'spec_helper' describe User do it 'testing create user time' do 100.times { user = double(“User”) user.should_not be_nil } end end Monday, May 27, 13 

$ time rspec spec/models/user_spec.rb . Finished in 0.02927 seconds 1 example, 0 failures Monday, May 27, 13 

RUBY MODULES Monday, May 27, 13 

RAILS DEPENDENCY == 0 Monday, May 27, 13 

#WINS Monday, May 27, 13 

FAST RAILS TESTS Monday, May 27, 13 

#WINS Monday, May 27, 13 

COMPOSITION vs INHERITANCE Monday, May 27, 13 

#WINS Monday, May 27, 13 

CODE ORGANIZATION Monday, May 27, 13 

#WINS Monday, May 27, 13 

Monday, May 27, 13 

OBRIGADO! Merci! Thanks! Gracias! Cheers Mate! хࢎ Monday, May 27, 13