Rails 3 & MongoMapper

app_models_paper.rb

class Paper
  include MongoMapper::Document
  
  key :url, String, :required => true
  key :read, Boolean
  key :archived, Boolean
  key :screenshot, Binary
  key :date, Date
  
  many :tags
end

config_initializers_mongo.rb

MongoMapper.connection = Mongo::Connection.new('localhost', 27017)
MongoMapper.database = "#myapp-#{Rails.env}"
 
if defined?(PhusionPassenger)
   PhusionPassenger.on_event(:starting_worker_process) do |forked|
     MongoMapper.connection.connect_to_master if forked
   end
end

Gemfile

gem "mongo_ext"
gem "mongo_mapper", :git => 'http://github.com/merbjedi/mongomapper.git', :branch => 'rails3'

MongoMapper_Rails3

gem "mongo_ext"
gem "mongo_mapper-rails3", :require => "mongo_mapper"

Rails installation

$ gem install i18n tzinfo builder memcache-client rack rack-test rack-mount erubis mail text-format thor bundler
$ gem install rails --pre