loggable.rb

require 'logger'
require 'colorize'

# This class provides a way for other modules or classes to have a
# logger automatically available, not having to define any other methods
#
# Examples
#
#    module Mod
#      include Loggable.new(progname: 'bla')
#    end
#
#    class B
#      include Mod
#    end
#
#    b = B.new
#    b.logger.info 'Hello World'
#
# USEFUL LINKS:
#  - http://solnic.eu/2012/08/13/subclassing-module-for-fun-and-profit.html
#
class Loggable < Module
  def initialize(log_file: 'default', log_level: :info, progname: nil)
    @log_file = log_file
    @log_level= log_level.to_s
    @progname = progname
  end

  def included(model)
    super
    define_accessors
  end

  private
    def define_accessors
      # define_method("log=") do |value|
      #   instance_variable_set(:@log, value)
      # end

      class_eval <<-RUBY
        def logger
          @logger ||= Logger.new("log/#{@log_file}.log").tap do |l|
            l.level     = Logger::const_get '#{@log_level.upcase}'
            l.formatter = Logger::Formatter.new
            l.progname  = '#{@progname}'
            l.info { "Starting logging for: #{@progname.blue.bold} @ #{@log_level.yellow}" }
          end
        end
      RUBY
    end
end