Fast mongoid single collection inheritance with Rails 3.1 Asset Pipeline.

development.rb

# Allows Mongoid's single collection inheritance to work with the Asset pipeline
# without enabling model preloading, which greatly reduces the performance of 
# the application in development mode.
# see: http://martinciu.com/2011/06/rails-3-1-and-slow-asset-pipeline.html
# see: http://groups.google.com/group/mongoid/browse_thread/thread/3d37977a321dc56d?pli=1
# see: http://mongoid.org/docs/rails/railties.html
config.to_prepare do 
  Dir["#{Rails.root}/app/models/*.rb"].each {|file| require file }
end