Rails 3 from A to Z

@speaker = { :name => ‘Matt Yoho’ , :company => EdgeCase , :writes => [ ‘Ruby on Rails’ ], :loves => [ ‘Comic Books’ ] }

Rails is a Domain Specific Language for web applications written in and on top of Ruby.

Rails 1.0 December 2005

Rails 2.0 December 2007

Rails 2.3 March 2009

Rails 3 .0 August 2010

Rails 3 .0.3 November 2010

Agenda

1) Rails Overview

2) Highlight new features

3) Example app

Rails concepts

M odel VC

MV iew C

MV C ontroller

Models Views Controllers Model View Controller

Models Views Controllers Helpers Model View Controller

Models Views Controllers Routes Helpers Model View Controller

class Movie < ActiveRecord :: Base has_many :nights belongs_to :genre validates :title , :presence => true validates :imdb_id , :presence => true , :uniqueness => true before_save :parse_posters def poster_url(size = :thumb ) self .posters.find do | p | p =~ / #{ size } .(jpg|png)Z/i end end end Model Domain logic, CRUD operations. Inherit from ActiveRecord :: Base

Model Domain logic, data persistence. Implement ActiveModel in Rails 3 class Movie < ActiveRecord :: Base has_many :nights belongs_to :genre validates :title , :presence => true validates :imdb_id , :presence => true , :uniqueness => true before_save :parse_posters def poster_url(size = :thumb ) self .posters.find do | p | p =~ / #{ size } .(jpg|png)Z/i end end end

Model Associations Validations Lifecycle callbacks class Movie < ActiveRecord :: Base has_many :nights belongs_to :genre validates :title , :presence => true validates :imdb_id , :presence => true , :uniqueness => true before_save :parse_posters def poster_url(size = :thumb ) self .posters.find do | p | p =~ / #{ size } .(jpg|png)Z/i end end end

< div class= ”movie” > < img src= ” <%= @movie .poster_url %> ” alt= ” <%= @movie .title %> ” /> < h3 ><%= @movie .title %></ h3 > <%= link_to( “See this movie” , movies_path( @movie )) %> </ div > View Presentation templates. Inherit from ActionView :: Base Erb and HAML

View Nested structure. Layouts Templates Partials Partials

View Contain < head > and < body > tags, basic stylesheets and JavaScript links. One or a few per app. Layouts

View Templates Contain page-specific markup and exist for approximately each controller action.

View Small, reusable template components. Partials Partials

class MoviesController < ApplicationController before_filter :user_of_age? def show id = params[ :id ] @movie = Movie .find(id) render ‘movies/show’ end private def user_of_age? unless current_user.age >= 17 redirect_to(root_path) end end end Controller Orchestrators that coordinate data retrieval and persistence, handle request and response bookkeeping, and render views to client. Inherit from ActionController :: Base (In practice, ApplicationController )

Controller Rendering Redirection Filters class MoviesController < ApplicationController before_filter :user_of_age? def show id = params[ :id ] @movie = Movie .find(id) render ‘movies/show’ end private def user_of_age? unless current_user.age >= 17 redirect_to(root_path) end end end

module MoviesHelper def movie_name(night) if night.movie.present? night.movie_title else "DUNNO YET" end end end end Helpers Presentation logic that should be kept out of templates but does not belong on models. Modules, not classes. Presenter models are an alternative.

Movies :: Application .routes.draw do resources :movies do resources :votes , :only => [ :create , :destroy ] end end end Routes Mappings from incoming requests to controller actions (or occasionally elsewhere.) Rails 3 brings new capabilities.

class Notifier < ActionMailer :: Base default :from => "invites@movienight.com" , :subject => "You are invited!" def invited (invitation) headers[ :content_type ] = 'text/html' @night = invitation.night @invitee = invitation.invitee mail :to => invitation.email endend end end Mailer Controller-like classes that render mail messages. Can handle multi-part (plain text/HTML) and attachments. Inherit from ActionMailer::Base

Don’t Repeat Yourself

class CreateMovies < ActiveRecord :: Migration def self .up create_table :movies do | t | t.string :title t.string :imdb_id t.datetime :release t.text :posters t.timestamps end end def self .down drop_table :movies end end Migrations

class Movie < ActiveRecord :: Base validates :title , :presence => true validates :imdb_id , :presence => true , :uniqueness => true before_save :parse_posters def poster_url( size = :thumb ) self .posters.find do |p| p =~ / #{size} .(jpg|png)Z/i end end end Model

ConventionConfiguration

Define APIs

Define RESTful APIs

Resources

Identified by URIs

http://movienight.com/movies/123

Movie id = 123 ... http://movienight.com/movies/123

May be nested

http://movienight.com/movies/123/actors/4

Movie id = 123 http://movienight.com/movies/123/actors/4 Actor id = 4

May have multiple representations

http://movienight.com/movies/123.json

http://movienight.com/movies/123.json {"movie" : {"alt_title" : "Batman Begins", "created_at" : "2011-01-07T15:51:50Z", "id" :33, "imdb_id" : "tt0096251", "popularity" : 2.0, "posters" : ["http://images.themoviedb.org/posters/1113/poster2rz_thumb.jpg "], "release" : "2005-06-17T00:00:00Z", "title" : "Batman Begins", "tmdb_id" : "18393", "updated_at" : "2011-01-07T15:51:50Z"}} {JSON}

http://movienight.com/movies/123.xml

http://movienight.com/movies/123.xml <?xml version="1.0" encoding="UTF-8"?> <movie> <title>Batman Begins</title> <created-at type="datetime"> 2011-01-06T22:18:44Z </created-at> <id type="integer">13</id> <imdb-id>tt0372784</imdb-id> <release type="datetime"> 2005-06-17T00:00:00Z </release> <tmdb-id>272</tmdb-id> </movie> <xml>

Rely on HTTP content type negotiation

HTTP headers

HTTP headers http://movienight.com/movies/123.json

Accept: application/json, text/javascript, */* ; Request header

Content-Type: application/json; Response header

CRUD via HTTP VERBS

GET POST PUT DELETE HTTP verbs

READ CREATE UPDATE DELETE CRUD operations

SHOW CREATE UPDATE DESTROY Rails controller actions

SHOW CREATE UPDATE DESTROY NEW EDIT INDEX

GET /movies/123 HTTP/1.1 Accept:text/html

GET /movies/123 HTTP/1.1 Accept:text/html CRUD op

GET /movies/123 HTTP/1.1 Accept:text/html Resource

GET /movies/123 HTTP/1.1 Accept:text/html MoviesController#show

Strongly encouraged by Rails

Request -> Response Cycle

Models Views Controllers Routes Request-response cycle Client

Models Views Controllers Routes Request-response cycle Client Webpage!

Feature details

Bundler

Commands

rails new ~/app/name

rails new ~/app/name -T -J

rails new ~/app/name -T -J -T = Skip Test::Unit

rails new ~/app/name -T -J -J = Skip Prototype

rails generate < thing >

rails server

rails console

Dependency Management

can't activate cucumber (= 0.4.4, runtime) for [], already activated cucumber-0.6.1 for [] (Gem::LoadError)

$ gem install rails -v2.3.10Successfully installed activesupport-2.3.9Successfully installed activerecord-2.3.9Successfully installed actionpack-2.3.9Successfully installed actionmailer-2.3.9Successfully installed activeresource-2.3.9Successfully installed rails-2.3.96 gems installed 2.3

$ gem install rails -v3.0.3Successfully installed activesupport-3.0.3Successfully installed builder-2.1.2Successfully installed i18n-0.5.0Successfully installed activemodel-3.0.3Successfully installed rack-1.2.1Successfully installed rack-test-0.5.7Successfully installed rack-mount-0.6.13Successfully installed tzinfo-0.3.23Successfully installed abstract-1.0.0Successfully installed erubis-2.6.6Successfully installed actionpack-3.0.3Successfully installed arel-2.0.6Successfully installed activerecord-3.0.3Successfully installed activeresource-3.0.3Successfully installed mime-types-1.16Successfully installed polyglot-0.3.1Successfully installed treetop-1.4.9Successfully installed mail-2.2.13Successfully installed actionmailer-3.0.3Successfully installed thor-0.14.6Successfully installed railties-3.0.3Successfully installed bundler-1.0.7Successfully installed rails-3.0.323 gems installed 3.0

Gemfile

source 'http://rubygems.org' gem 'rails' , '~> 3.0.3' gem 'basic_assumption' , '~> 0.4.1' gem 'devise' , '~> 1.1.5' gem 'dynamic_form' , '~> 1.1.3' gem 'haml' , '~> 3.0.24' gem 'nokogiri' , '~> 1.4.4' gem 'pg' , '~> 0.9.0' gem 'ruby-debug' , '~> 0.10.3' , :platforms => :mri_18 gem 'ruby-debug19' , '~> 0.11.6' , :platforms => :mri_19 group :test do gem 'rspec-rails' , '~> 2.4.1' gem 'factory_girl_rails' , '~> 1.0.0' gem 'fakeweb' , '~> 1.3.0' end end end

source 'http://rubygems.org'

gem 'rails' , '~> 3.0.3'

gem 'rails' , '~> 3.0.3' Name

gem 'rails' , '~> 3.0.3' Version

:mri :mri_18 :mri_19 :mswin :jruby Platforms

gem 'ruby-debug' , :platforms => :mri_18

gem 'ruby-debug19' , :platforms => :mri_19

Install from Git

gem 'basic_assumption' , :git => 'git://github.com/mattyoho/basic_assumption.git' , :branch => 'experimental'

gem 'basic_assumption' , :git => 'git://github.com/mattyoho/basic_assumption.git' , :branch => 'experimental' GitHub repo

gem 'basic_assumption' , :git => 'git://github.com/mattyoho/basic_assumption.git' , :branch => 'experimental' Git repo branch

bundle install

group :test do gem 'rspec-rails' gem 'cucumber' gem 'fakeweb' end end

bundle install --without test

bundle open < gem name >

bundle update

bundle package

http://gembundler.org/ http://gembundler.com/man/gemfile.5.html

MATT YOHO RAILS 3 FROM A TO Z Models MATT YOHO RAILS 3 FROM A TO Z

The great split

ActiveRecord MATT YOHO RAILS 3 FROM A TO Z

ActiveRecord ActiveModel ActiveRelation

ActiveModel

ActiveModel :: Validations ActiveModel :: Callbacks ActiveModel :: Errors ActiveModel :: Dirty

validates :title , :presence => true :format => /[a-zA-Z]/

ActiveModel :: Lint

Mongoid Datamapper

ActiveRelation

Not as speedy?

@tenderlove Comeplete rewrite of Arel

Movie . select( ‘*’ ) where( “title ILIKE %batman%” ). order( ‘release DESC’ )

criteria = Movie . select( ‘*’ ) where( “title ILIKE %batman%” ). order( ‘release DESC’ )

criteria = Movie . select( ‘*’ ) where( “title ILIKE %batman%” ). order( ‘release DESC’ ) criteria.to_sql

"SELECT * FROM "movies" WHERE (title ILIKE '%batman%') ORDER BY title"

select() where() order() joins() includes() limit() group() having() etc.

named_scope

scope :batman_flicks , where( “title ILIKE %batman%” )

default_scope order( “title” )

MATT YOHO RAILS 3 FROM A TO Z Controllers

MATT YOHO RAILS 3 FROM A TO Z ActionController respond_to

MATT YOHO RAILS 3 FROM A TO Z ActionController class MoviesController < ApplicationController def show @movie = Movie .find(params[:id]) respond_to do | format | format.json { render :json => @movie .to_json } format.xml { render :json => @movie .to_xml } format.html { render ‘movies/show’ } end endend end

MATT YOHO RAILS 3 FROM A TO Z ActionController respond_with

MATT YOHO RAILS 3 FROM A TO Z ActionController class MoviesController < ApplicationController respond_to :json , :xml , :html def show @movie = Movie .find(params[:id]) respond_with( @movie , :status => :ok ) endend end

MATT YOHO RAILS 3 FROM A TO Z ActionMailer class Mailer < ActionMailer :: Base default :from => "invites@movienightapp.com" , :subject => "You’ve been invited to a movie night!" def invitation( invitation ) headers[ :content_type ] = 'text/html' @night , @invitee = invitation.night, invitation.invitee mail :to => invitation.email endend end

MATT YOHO RAILS 3 FROM A TO Z ActionMailer class Mailer < ActionMailer :: Base default :from => "invites@movienightapp.com" , :subject => "You’ve been invited to a movie night!" def invitation( invitation ) headers[ :content_type ] = 'text/html' @night , @invitee = invitation.night, invitation.invitee mail :to => invitation.email endend end message = Mailer .invitation( @invitation ) message.deliver

MATT YOHO RAILS 3 FROM A TO Z mail gem

MATT YOHO RAILS 3 FROM A TO Z ActionMailer :: Base AbstractController::Base ActionController :: Base

Whitelist, not blacklist

<%= h ( @movie .description) %>

<%= @movie .description %>

<%= raw( “<h2> #{ @movie .title } </h2>” ) %>

<%= raw( “<h2> #{ @movie .title } </h2>” ) %> String #html_safe

Unobtrusive JS

link_to_remote "Destroy" , :url => movie_url( @movie ), :method => :delete

<a href="#" onclick="new Ajax.Request('/movies/4', {asynchronous:true, evalScripts:true, method:'delete'}); return false;">Destroy</a> link_to_remote "Destroy" , :url => movie_url( @movie ), :method => :delete

link_to "Destroy" , movie_url( @movie ), :remote => true , :method => :delete

<a href="/movies/4" data-remote=”true" data-method=”delete”>Destroy</a> link_to "Destroy" , movie_url( @movie ), :remote => true , :method => :delete

https://github.com/rails/jquery-ujs

Routing

Pneumatic tubes, popular in the late 19th and early 20th century for transporting messages, cash, etc.

Text Resources

CoffeeShop :: Application .routes.draw do resources :cups do resources :shots end resources :coffee_beans end end

cup_shots GET /cups/:cup_id/shots(.:format) {:action=>"index", :controller=>"shots"} POST /cups/:cup_id/shots(.:format) {:action=>"create", :controller=>"shots"} new_cup_shot GET /cups/:cup_id/shots/new(.:format) {:action=>"new", :controller=>"shots"} edit_cup_shot GET /cups/:cup_id/shots/:id/edit(.:format) {:action=>"edit", :controller=>"shots"} cup_shot GET /cups/:cup_id/shots/:id(.:format) {:action=>"show", :controller=>"shots"} PUT /cups/:cup_id/shots/:id(.:format) {:action=>"update", :controller=>"shots"} DELETE /cups/:cup_id/shots/:id(.:format) {:action=>"destroy", :controller=>"shots"} cups GET /cups(.:format) {:action=>"index", :controller=>"cups"} POST /cups(.:format) {:action=>"create", :controller=>"cups"} new_cup GET /cups/new(.:format) {:action=>"new", :controller=>"cups"} edit_cup GET /cups/:id/edit(.:format) {:action=>"edit", :controller=>"cups"} cup GET /cups/:id(.:format) {:action=>"show", :controller=>"cups"} PUT /cups/:id(.:format) {:action=>"update", :controller=>"cups"} DELETE /cups/:id(.:format) {:action=>"destroy", :controller=>"cups"} coffee_beans GET /coffee_beans(.:format) {:action=>"index", :controller=>"coffee_beans"} POST /coffee_beans(.:format) {:action=>"create", :controller=>"coffee_beans"} new_coffee_bean GET /coffee_beans/new(.:format) {:action=>"new", :controller=>"coffee_beans"}edit_coffee_bean GET /coffee_beans/:id/edit(.:format) {:action=>"edit", :controller=>"coffee_beans"} coffee_bean GET /coffee_beans/:id(.:format) {:action=>"show", :controller=>"coffee_beans"} PUT /coffee_beans/:id(.:format) {:action=>"update", :controller=>"coffee_beans"} DELETE /coffee_beans/:id(.:format) {:action=>"destroy", :controller=>"coffee_beans"}

cups GET /cups(.:format) {:action=>"index"} POST /cups(.:format) {:action=>"create} new_cup GET /cups/new(.:format) {:action=>"new"}edit_cup GET /cups/:id/edit(.:format) {:action=>"edit"} cup GET /cups/:id(.:format) {:action=>"show"} PUT /cups/:id(.:format) {:action=>"update"} DELETE /cups/:id(.:format) {:action=>"destroy} :controller=>"cups"

cups GET / cups (.:format) {:action=>" index "} POST / cups (.:format) {:action=>" create } new_cup GET /cups/new(.:format) {:action=>"new"}edit_cup GET /cups/:id/edit(.:format) {:action=>"edit"} cup GET /cups/:id(.:format) {:action=>"show"} PUT /cups/:id(.:format) {:action=>"update"} DELETE /cups/:id(.:format) {:action=>"destroy} :controller=>"cups"

cups GET /cups(.:format) {:action=>"index"} POST /cups(.:format) {:action=>"create} new_cup GET /cups/new(.:format) {:action=>"new"}edit_cup GET /cups/:id/edit(.:format) {:action=>"edit"} cup GET / cups/:id (.:format) {:action=>" show "} PUT /cups/:id (.:format) {:action=>" update "} DELETE /cups/:id(.:format) {:action=>"destroy} :controller=>"cups"

CoffeeShop :: Application .routes.draw do resources :cups do resources :shots end resources :coffee_beans , :except => :destroy end end

CoffeeShop :: Application .routes.draw do resources :cups do resources :shots end resources :coffee_beans , :only => [ :new , :show ] end end

CoffeeShop :: Application .routes.draw do resources :cups do resources :shots end resources :coffee_beans , :path_names => [ :edit => ‘brew’ ] end end

CoffeeShop :: Application .routes.draw do resources :cups do resources :shots end resources :coffee_beans resource :shop , :except => [ :destroy ] end

Singular Routes

Movienight :: Application .routes.draw do match "/search" , :to => "movies#search" end Simple routes

Movienight :: Application .routes.draw do match "/search" , :to => "movies#search" , :as => "title_search" end Named routes

Movienight :: Application .routes.draw do match "/search" , :to => "movies#show" , :via => :get end Method-constrained routes

Movienight :: Application .routes.draw do get "/search" , :to => "movies#search" , :via => :get end Method-constrained routes

Movienight :: Application .routes.draw do root :to => "nights#index" end Root route

Non-resourceful Methods

CoffeeShop :: Application .routes.draw do resources :coffee_beans do collection do get :dark_roast get :light_roast end member do put :chew end endend end

Constraints

Movienight :: Application .routes.draw do match "/search" , :constraints => { :subdomain => "mst3k" } end

Movienight :: Application .routes.draw do match "/movies/:imdb_id" , :constraints => { :imdb_id => /d+/ } end

Movienight :: Application .routes.draw do constraints( :subdomain => "mst3k" ) do resource :projector do resources :bmovies end end end

Optional Segments

# Rails 2 ActionController :: Routing :: Routes .draw do | map | map.connect "/:controller/:action/:id" end # Rails 3 Movienight :: Application .routes.draw do match "/:controller(/:action(/:id))(.:format)" end end end

Rack Endpoints

Movienight :: Application .routes.draw do match "/hello" , :to => Proc .new do | env | [ 200 , { ‘Content-Type’ => ‘text/plain’ }, [ “Hello, world” ] ] end end

Movienight :: Application .routes.draw do match "/hello" , :to => Proc .new do | env | [ 200 , { ‘Content-Type’ => ‘text/plain’ }, [ “Hello, world” ] ] end end hello /hello(.:format) {:to=>#<Proc:0x00000100f1da28@/app/config/routes.rb:7>}

Sinatra MATT YOHO RAILS 3 FROM A TO Z

require 'sinatra/base' class ApiApp < Sinatra :: Base get "/hello" do whom = request.cookies[ "whom" ] whom ||= "world" set_cookie( ‘whom’ , whom) "Hello, #{ whom } " end post "/hello" do set_cookie( ‘whom’ , params [ :whom ]) redirect "/hello" end end

Movienight :: Application .routes.draw do scope "/api" do match "(*path)" , :to => ApiApp endend end

Movienight :: Application .routes.draw do mount ApiApp , :at => "/api" end

Special case?

Movienight :: Application .routes.draw do match "/search" , :to => "movies#search" end

MoviesController .action( :search ) Movienight :: Application .routes.draw do match "/search" , :to => "movies#search" end

Movienight :: Application .routes.draw do devise_for :users resources :nights do resources :invitations , :except => [ :index , :destroy ], :path_names => { :edit => 'confirm' } end resources :locations , :except => [ :new , :show ] resources :movies do collection do get :title_search end end root :to => "nights#index" end end

Example

Movienight

Resources

http://railsapi.com

Rails for Zombies http://railsforzombies.org /

Rails 3 Cheat Sheets http://blog.envylabs.com/2010/12/rails-3-cheat-sheets/

Rails 3 Upgrade Handbook http://www.railsupgradehandbook.com/

Rails 3 from A to Z

by Matt Yoho on Jan 25, 2011

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Rails 3 from A to Z — Presentation Transcript

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