What's new in Rails 4
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This document summarizes the key new features in Rails 4, including: - Support for Ruby 2.0 and dropping support for older Ruby versions. - Performance improvements to caching and database access. - Enhancements to ActiveRecord like the where method and scopes. - Strong parameters for sanitizing nested attributes. - The PATCH HTTP method and routing concerns. - Updates to ActiveModel and views like collection helpers.
![class User < ActiveRecord::Base
def visible_posts
case role
when 'Country Manager'
Post.where(country: country)
when 'Reviewer'
Post.published
when 'Bad User'
[]
end
end
end](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-16-320.jpg)
![@posts = current_user.visible_posts
if @posts.any?
@posts.recent
else
[]
end](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-17-320.jpg)
![class User < ActiveRecord::Base
attr_accessible :name
end
# Controller
def update
if @user.update_attributes(params[:user])
redirect_to @user, notice: 'Updated'
end
end](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-25-320.jpg)
![Strong Parameters
class User < ActiveRecord::Base
end
# Controller
def update
user_params = params.require(:user).permit(:name)
if @user.update(params[:user])
redirect_to @user, notice: 'Updated'
end
end](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-26-320.jpg)
![#before_action
before_filter :set_user, only: [:update]
before_action :set_user, only: [:update]](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-32-320.jpg)
![Flash messages
<p id="notice"><%= flash[:notice] %></p>
<p id="notice"><%= notice %></p>](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-34-320.jpg)
![date fields
<%= f.date_field :return_date %>
<input id="item_return_date" name="item[return_date]" type="date">](https://image.slidesharecdn.com/whatsnewinrails4-130611111313-phpapp01/85/What-s-new-in-Rails-4-38-320.jpg)
What's new in Rails 4
- 1. What's new in Rails 4 Lucas Caton
- 3. 4
- 4. May 1, 2013 Rails 4.0: Release Candidate 1 released!
- 5. Ruby 1.8.7 Ruby 1.9.2 Ruby 1.9.3 Ruby 2.0.0
- 6. RubyGems 2.x
- 7. ThreadSafety
- 8. memcache-client dalli => 20% faster => ThreadSafe => Easier to integrate with NewRelic RPM
- 11. #find_or_* Post.find_or_initialize_by_title('Rails 4') Post.find_or_initialize_by(title:'Rails4')
- 14. #all @posts = Post.scoped @posts = Post.all ActiveRecord::Relation
- 15. Scopes scope :sold, where(state: 'sold') default_scope where(state: 'available') scope :sold, ->{ where(state: 'sold') } default_scope ->{ where(state: 'available') }
- 16. class User < ActiveRecord::Base def visible_posts case role when 'Country Manager' Post.where(country: country) when 'Reviewer' Post.published when 'Bad User' [] end end end
- 17. @posts = current_user.visible_posts if @posts.any? @posts.recent else [] end
- 18. #none class User < ActiveRecord::Base def visible_posts case role when 'Country Manager' Post.where(country: country) when 'Reviewer' Post.published when 'Bad User' Post.none end end end
- 19. #not if author Post.where('author != ?', author) else Post.where('author IS NOT NULL') end Post.where.not(author: author)
- 20. #order User.order('created_at DESC') User.order(:name, 'created_at DESC') User.order(created_at: :desc) User.order(:name, created_at: :desc)
- 21. ActiveModel 4
- 22. ActiveModel class SupportTicket include ActiveModel::Conversion include ActiveModel::Validations extend ActiveModel::Naming extend ActiveModel::Translation attr_accessor :title, :description validates_presence_of :title validates_presence_of :description end
- 23. ActiveModel class SupportTicket include ActiveModel::Model attr_accessor :title, :description validates_presence_of :title validates_presence_of :description end
- 25. class User < ActiveRecord::Base attr_accessible :name end # Controller def update if @user.update_attributes(params[:user]) redirect_to @user, notice: 'Updated' end end
- 26. Strong Parameters class User < ActiveRecord::Base end # Controller def update user_params = params.require(:user).permit(:name) if @user.update(params[:user]) redirect_to @user, notice: 'Updated' end end
- 27. Routes 4
- 28. match '/items/:id/purchase', to: 'items#purchase' XSS Attack (Cross-site Scripting) post '/items/:id/purchase', to: 'items#purchase' match '/items/:id/purchase', to: 'items#purchase', via: :post match '/items/:id/purchase', to: 'items#purchase', via: :all
- 29. PATCH Method for HTTP Abstract Several applications extending the Hypertext Transfer Protocol (HTTP) require a feature to do partial resource modification. The existing HTTP PUT method only allows a complete replacement of a document. This proposal adds a new HTTP method, PATCH, to modify an existing HTTP resource. http://tools.ietf.org/html/rfc5789
- 30. $ rake routes items GET /items(.:format) items#index POST /items(.:format) items#create new_item GET /items/new(.:format) items#new edit_item GET /items/:id/edit(.:format) items#edit item GET /items/:id(.:format) items#show PUT /items/:id(.:format) items#update PATCH /items/:id(.:format) items#update DELETE /items/:id(.:format) items#destroy PATCH HTTP verb
- 32. #before_action before_filter :set_user, only: [:update] before_action :set_user, only: [:update]
- 33. Encrypted cookie stored in the browser
- 34. Flash messages <p id="notice"><%= flash[:notice] %></p> <p id="notice"><%= notice %></p>
- 35. Streaming
- 36. Views 4
- 37. collections helpers <% @owners.each do |owner| %> <%= radio_button_tag :owner_id, owner.id %> <%= owner.name %> <% end %> collection_radio_buttons(:item, :owner_id, @owners, :id, :name) collection_check_boxes(:item, :owner_id, @owners, :id, :name)
- 38. date fields <%= f.date_field :return_date %> <input id="item_return_date" name="item[return_date]" type="date">
- 39. date fields <%= f.date_field :return_date %>
- 40. TurboLinks aka. full page pjax
- 41. Other improvements => Routing Concerns => Test Folder Structure => Caching improvements => Custom Flash Types => ActionController Live => ETags => jbuilder template handler
- 42. Links Rails Guides - Upgrading from Rails 3.2 to Rails 4.0: http://edgeguides.rubyonrails.org/ upgrading_ruby_on_rails.html#upgrading-from-rails-3-2-to- rails-4-0 Rails Casts - Upgrading to Rails 4 http://railscasts.com/episodes/415-upgrading-to-rails-4 Code School - Learn Rails 4 best practices http://www.codeschool.com/courses/rails-4-zombie- outlaws
- 43. Thank you!