Feature Flags / Rails + Mongoid

User.rb

class User
  include Mongoid::Document

  # herein might appear a metric shitton of fields
  # but what you need to know for feature flags follows
  
  field :feature_flags, :type => Hash, :default => {}

  # likewise, this is only what you need for 
  # feature flagging and nothing more
  
  def feature_enabled?(name)
    !self.feature_flags[name].blank? ? self.feature_flags[name] : false
  end
  
  def feature_added?(name)
    !self.feature_flags[name].nil? ? true : false
  end
  
  def enable_feature(name)
    self.feature_flags[name] = true
    self.save!
  end
  
  def disable_feature(name)
    self.feature_flags[name] = false
    self.save!
  end
  
  def self.enable_feature_globally(name)
    User.all.each do |u|
      u.enable_feature(name)
    end
  end
  
  def self.disable_feature_globally(name)
    User.all.each do |u|
      u.disable_feature(name)
    end
  end

end