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Note: The Active Record Identity Map feature is now disabled by default and is currently not recommended due to problems with associations. It looks like it will not make it into 3.1 final.
rvm 1.9.2@railspre --create
gem install rails --pre
rails new todo
rails g scaffold project name:string
p = Project.create!(:name => "Yardwork")
p2 = Project.find(1)
p.object_id == p2.object_id
alert "Hello world!"
has_many :assigments, :through => :tasks
has_many :users, :through => :assignments
attr_accessible :name, :as => :admin
@project.update_attributes(params[:project], :as => :admin)
<%= link_to "Edit", edit_project_url(@project, :subdomain => "foo") %>