adam_roles.rb

require_relative "roles/config"

module Adam
  class Roles
  end
end

adam_roles_config.rb

module Adam
  class Roles
    class Config #:nodoc:

      # Users::Roles.module_roles returns:
      # {"Users"=>[:admin], "Events"=>[:admin, :manager]}
      
      class << self
        attr_accessor :roles, :module_roles
      end

      def self.configure(&block)
        if block_given?
          calling_module = eval("self", block.binding)
          if calling_module.to_s == "main"
            raise "Users::Roles.configure must be called in a module"
          end
          module_roles = instance_eval(&block)

          @module_roles ||= {}
          @module_roles[calling_module.to_s] = module_roles
          yield self
        end

        self
      end
    end
  end
end

user_roles.rb

module Users
  # Internally we use the {Pundit gem}[https://github.com/elabs/pundit] for authorization. Each
  # component that needs authorization access by role must inject the roles that it needs into
  # this Users component.
  #
  # Roles should be injected in the component lib/component_name.rb file. For example, the Events
  # component lib/events.rb file would declare an admin role with:
  #
  #     module Events
  #       require "events/engine"
  #
  #       ROLES = [:admin]
  #       Users::Roles.configure do |config|
  #         config.roles = ROLES
  #       end
  #     end
  #
  # With Users::Roles configured the Users will allow roles to be assigned to groups of users.
  # Components using authorization will also need to include the Users::SessionsHelper and
  # Users::Authentication module into the components ApplicationController. ex:
  #
  #     module Events
  #       class ApplicationController < ActionController::Base
  #         include Users::SessionsHelper
  #
  #         include Users::Authentication
  #       end
  #     end
  class Roles < Adam::Roles
  end
end