This document provides an overview of the key changes in migrating from Rails 2 to Rails 3. It discusses updates to components like routing, controllers, models and views. Specific changes include moving to RESTful routing, removing deprecated methods like link_to_remote, and adopting unobtrusive JavaScript. Links are provided for additional documentation on routing, controllers, mailers and other aspects of the Rails 3 framework.

1. Rails 3 For Rails 2 Developers

2. Components

3. Lifecycle

4. Controller Stack

5. Creating a Rails 3 app rvmgemset create rails3 rvmgemset use rails3 gem install rails --pre rails new test_app

6. Scripts

7. Look at: environment.rb application.rb config.ru

8. Routes - compatibility Old Style TestApp::Application.routes.drawdo |map| map.resources:posts do |post|post.resources:comments end end New Style TestApp::Application.routes.drawdo |map|resources:posts do resources :comments end end

9. Routes - resources Old Style post.resources:comments, :member => { :preview => :post }, :collection => { :archived => :get } New Style resources :comments do post :preview, :on => :member get :archived, :on => :collection end

10. Routes – named routes Old Style map.connect'login’, :controller => 'session', :action => 'new' map.login'login’, :controller => 'session', :action => 'new’ New Style match 'login' => 'session#new’ match 'login' => 'session#new', :as => :login

11. Routes – root paths Old Style map.root:controller => 'users’, :action => 'index’ New Style root :to => 'users#index'

12. Routes - Rack Endpoints get 'hello' => proc { |env| [200, {}, "Hello Rack"] } get 'rack_endpoint' => PostsController.action(:index) get 'rack_app' => CustomRackApp

13. Routes Etc. Documentation here: http://guides.rails.info/routing.html

14. ActionController – Legacy Style class UsersController< ApplicationController def index @users = User.all respond_todo |format| format.html format.xml{ render :xml => @users.to_xml} end end def show @user = User.find(params[:id]) respond_todo |format| format.html# show.html.erb format.xml{ render :xml => @user } end end end

15. ActionController – New Style class UsersController< ApplicationControllerrespond_to:html, :xml, :json def index @users = User.all respond_with(@users) end def show @user = User.find(params[:id]) respond_with(@user) end end

16. ActionMailer def welcome(user, subdomain) @user = user @subdomain= subdomain mail(:from=>admin@testapp.com, :to => user.email, :subject => "Welcome to TestApp") End UserMailer.welcome(user, subdomain).deliver

17. ActionMailer class UserMailer< ActionMailer::Base default :from => "admin@testapp.com", :reply_to=> "noreply@testapp.com", "X-Time-Code" => Time.now.to_i.to_s def welcome(user, subdomain) @user = user @subdomain= subdomain attachments['test.pdf'] = File.read("#{Rails.root}/public/test.pdf") mail(:to=> @user.email, :subject => "Welcome to TestApp") do |format|format.html{ render 'other_html_welcome' } format.text{ render 'other_text_welcome' } end end end

18. ActiveRelation Rails2 @posts = Post.find(:all, :conditions => {:published => true}) @posts = Post.find(:all, :conditions => {:author => "Joe"}, :includes => :comments, :order => "title", :limit => 10) Rails3 @posts = Post.where(:published=> true) @posts = Post.where(:author=> "Joe").include(:comments).order(:title).limit(10).all

19. ActiveRelation - scopes Rails2 class Post < ActiveRecord::Base default_scope:order => 'title’ named_scope:published, :conditions => {:published => true} named_scope:unpublished, :conditions => {:published => false} end Rails3 class Post < ActiveRecord::Base default_scopeorder('title') scope :published, where(:published=> true)scope:unpublished, where(:published=> false) end

20. ActiveRelation – new finder methods where (:conditions) having (:conditions) select group order limit offset joins includes (:include) lock readonly from

21. ActiveModel Attribute methods Callbacks Dirty Errors Naming Observing Serialization Translation Validations

22. ActiveModel - example class Applicant include ActiveModel::Validationsvalidates_presence_of:name, :email attr_accessor:name, :email end

23. XSS

24. XSS Rails2 <%=@post.body %> <%= h@post.body %> Rails3 <%= raw @post.body %> <%= @post.body.html_safe %> <%= @post.body %>

25. Unobtrusive Javascript HTML 5 custom data attributes: data-* data-remote data-method data-confirm data-disable-with

26. Unobtrusive Javascript Rails2 <%= link_to_remote'Show', :url=> post %> <a href="#" onclick="new Ajax.Request('/posts/1', {asynchronous:true, evalScripts:true, parameters:'authenticity_token=' + encodeURIComponent('9sk..44d')}); return false;">Show</a> Rails3 <%= link_to'Show', post, :remote => true %> <a href="/posts/1" data-remote="true">Show</a>

27. Unobtrusive Javascript Rails2 <% remote_form_for(@post) do |f| %> <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;"> Rails3 <%= form_for(@post, :remote => true) do |f| %> <form action="/posts" class="new_post" data-remote="true" id="new_post" method="post">

28. Unobtrusive Javascript <%= link_to'Destroy', post, :confirm => 'Are you sure?', :method => :delete %> Rails2 <a href="/posts/1" onclick="if (confirm('Are you sure?')) { varf = document.createElement('form'); f.style.display = 'none'; this.parentNode.appendChild(f); f.method = 'POST'; f.action = this.href;varm = document.createElement('input'); m.setAttribute('type', 'hidden'); m.setAttribute('name', '_method'); m.setAttribute('value', 'delete'); f.appendChild(m);vars = document.createElement('input'); s.setAttribute ('type', 'hidden'); s.setAttribute('name', 'authenticity_token'); s.setAttribute('value', '9skdJ0k+l9/ q3PWToz6MtfyiB2gcyhnKubeGV6WFL44='); f.appendChild(s);f.submit(); };return false;">Destroy</a> Rails3 <a href="/posts/1" data-method="delete" rel="nofollow">Destroy</a> <a href="/posts/1" data-confirm="Are you sure?" data-method="delete" rel="nofollow">Destroy</a>

29. Unobtrusive Javascript Rails2 <%= f.submit'Create Post', :disable_with=> "Please wait..." %> <input id="post_submit" name="commit" onclick="if (window.hiddenCommit) { window.hiddenCommit.setAttribute('value', this.value); }else { hiddenCommit = document.createElement('input');hiddenCommit.type = 'hidden';hiddenCommit.value = this.value;hiddenCommit.name = this.name;this.form.appendChild(hiddenCommit); } this.setAttribute('originalValue', this.value);this.disabled = true;this.value='Please wait...';result = (this.form.onsubmit ? (this.form.onsubmit() ? this.form.submit() : false) : this.form.submit());if (result == false) { this.value = this.getAttribute ('originalValue');this.disabled = false; }return result;" type="submit" value="Create Post" /> Rails3 <%= f.submit:disable_with=> "Please wait..." %> <input data-disable-with="Please wait..." id="post_submit" name="commit" type="submit" value="Create Post" />

30. Unobtrusive Javascript Deprecated Methods: link_to_remote remote_form_for observe_field observe_form form_remote_tag button_to_remote submit_to_remote link_to_function periodically_call_remote

31. Links Rails Guides http://guides.rails.info/ Rails3 Ropes coursehttp://en.oreilly.com/rails2010/public/schedule/detail/14137 Reading Listhttp://mediumexposure.com/rails-3-reading-material/ Screencastshttp://rubyonrails.org/screencasts/rails3/