10 cool things in Rails 2.3
Luke Francl

Boots Faster in Development
Empty Rails app (real time)
time script/server -d
Rails 2.2 Rails 2.3
1.461s 0.869s

Boots Faster in Development
n-
no !
lly Empty Rails app (real time)
fic
ta nti time script/server -d
To cie
s
Rails 2.2 Rails 2.3
1.461s 0.869s

Support for Rails Engines
Photo: Wikipedia

Routing Improvements

Routing Improvements
RESTful routes use 50% less memory
because formatted_* routes are no longer
generated.
Before:
formatted_users_path('xml')
formatted_users_path(:format => 'xml')
Now:
users_path(:format => 'xml')

Routing Improvements
Routes no longer inherit :only and :except.
Before:
map.resources :users, :only => :show do |user|
user.resources :hobbies, :except => :none
end
Now:
map.resources :users, :only => :show do |user|
user.resources :hobbies
end

JSON Improvements

JSON Improvements
JSON keys are always quoted, per the spec.
Before:
{123 => 'abc'}.to_json
=> '{123: \"abc\"}'
Now:
{123 => 'abc'}.to_json
=> '{\"123\": \"abc\"}'

JSON Improvements
Unicode escape sequences are unescaped.
Before:
ActiveSupport::JSON.decode
(\"{'hello': 'fa\\\\u00e7ade'}\")
=> {\"hello\"=>\"fa\\\\u00e7ade\"}
Now:
ActiveSupport::JSON.decode
(\"{'hello': 'fa\\u00e7ade'}\")
=> {\"hello\"=>\"façade\"}

Default Scopes
default_scope :order => 'name asc'
# will use default scope
User.all
# will use passed in order option.
User.all(:order => 'name desc')
puts User.all.map { |u| \"#{u.id} - #{u.name}\" }
3 - Alice
2 - Bob
1 - George

Nested Transactions
User.transaction do
user = User.create(:name => 'Luke')
User.transaction(:requires_new => true) do
user.hobbies.create(:name => 'Knitting')
raise ActiveRecord::Rollback(\"Oh noes!!!\")
end
end

Asset Host Objects
class SslAssetHost
def call(source, request)
if request.ssl?
\"#{request.protocol}#{request.host_with_port}\"
else
\"#{request.protocol}assets.example.com\"
end
end
end

Override Timestamp Fields
User.create(:name => \"Alice\",
:created_at => 3.weeks.ago,
:updated_at => 2.weeks.ago)
=> #<User id: 3, name: \"Alice\",
created_at: \"2009-03-08 00:06:58\",
updated_at: \"2009-03-15 00:06:58\">

Nested Attributes...
class User < ActiveRecord::Base
has_many :hobbies, :dependent => :destroy
accepts_nested_attributes_for :hobbies
end
user = User.create(:name => 'Stan',
:hobbies_attributes =>
[{:name => 'Waterskiing'},
{:name => 'Hiking'}])

...and Forms
<% form_for(@user) do |f| %>
<%= f.label :name, \"User name:\" %>
<%= f.text_field :name %>
<h2>Hobbies</h2>
<% f.fields_for(:hobbies) do |hf| %>
<%= hf.label :name, \"Hobby name:\" %>
<%= hf.text_field :name %>
<% end %>
<%= f.submit 'Create' %>
<% end %>

Rails Metal
class UsersApi
def self.call(env)
if env['PATH_INFO'] =~ /^\\/users.js/
[200,
{'Content-Type' => 'application/json'},
User.all.to_json]
else
# Return 404 to let Rails handle the request
[404, {'Content-Type' => 'text/html'},
'not found']
end
end
end

Rails Metal \\m/
class UsersApi
def self.call(env)
if env['PATH_INFO'] =~ /^\\/users.js/
[200,
{'Content-Type' => 'application/json'},
User.all.to_json]
else
# Return 404 to let Rails handle the request
[404, {'Content-Type' => 'text/html'},
'not found']
end
end
end

Thanks!
Blog post:
http://railspikes.com/2009/3/30/10-cool-things-in-rails-23
Slides:
http://slideshare.net/lukefrancl/10-cool-things-about-rails-23
Code:
http://bitbucket.org/look/rails23-10coolfeatures/
Rails 2.3 Release Notes:
http://guides.rubyonrails.org/2_3_release_notes.html