usable.rb

module Usable
  def config
    @config ||= Config.new
  end

  def use(mod, options = {})
    send :include, mod unless self < mod
    if block_given?
      yield config
    else
      options.each { |k, v| config.public_send "#{k}=", v }
    end
  end

  class Config < OpenStruct
  end
end


# @description TEST CASES
=begin
module Versionable
  def versions
    "Saving #{self.class.config.max_versions} versions to #{self.class.config.table_name}"
  end
end

class Model
  extend Usable

  # with options hash
  use Versionable, table_name: 'custom_versions'

  # or with block
  use Versionable do |config|
    config.max_versions = 10
  end
end

Model.config.table_name #=> 'custom_versions'
Model.new.versions #=> "Saving 10 versions to custom_versions"
=end


#
# Separate configuration by module name to avoid naming collisions between modules
#

module Configurable
  def configs
    @configs ||= Hash.new do |me, key|
      me[key] = Config.new
    end
  end

  class Config < OpenStruct
  end
end

module Usable
  def self.extended(base)
    base.extend Configurable
  end

  def use(mod, options = {})
    send :include, mod unless self < mod
    if block_given?
      yield configs[mod]
    else
      options.each { |k, v| configs[mod].public_send "#{k}=", v }
    end
  end
end

# @description TEST CASE
=begin
module Versionable
  def versions
    config = self.class.configs[Versionable]
    "Saving #{config.max_versions} versions to #{config.table_name}"
  end
end

module Notable
  def notes
    config = self.class.configs[Notable]
    "Saving #{config.max_versions} notes to #{config.table_name}"
  end
end

class Model
  extend Usable
  
# with options hash
  use Versionable, table_name: 'custom_versions'

# or with block
  use Versionable do |config|
    config.max_versions = 10
  end

  use Notable do |config|
    config.max_versions = 20
    config.table_name = 'custom_notes'
  end
end

Model.config.table_name #=> 'custom_versions'
Model.new.versions #=> "Saving 10 versions to custom_versions"
Model.new.notes #=> "Saving 20 notes to custom_notes"
=end