gistfile1.txt

#!/usr/bin/env ruby


require 'logger' # requires belong *outside*

module LogInterceptors
  LOGGER = Logger.new(STDOUT)
  LOGGER.level = Logger::DEBUG

  def log_all
    log /.*/
  end

  def log regex
    raise "parameter must be of type Regexp ( just do /regex/ )" unless regex.is_a? Regexp
    mod = Module.new
    extend mod

    class_str = to_s

    methods.each do |m|
      if m.to_s.match regex
        mod.send(:define_method, m) do |*a| 
          start = Time.now
          result = super
          LOGGER.debug "#{class_str}: #{m}(#{a.map { |arg| arg.inspect }.join(', ')}): #{Time.now - start}"
          result 
        end
      end
    end
  end
end


class Interceptors::Example
  # you must include LogInterceptor to use it
  extend LogInterceptors
  
  # you can log every method call, be it a class method call
  log_all
  
  def initialize
    # or a instance method call. You can even log only specific methods based on regular expressions
    log /test/
  end
  
  def test
    puts "a test"
  end
end

Interceptors::Example.new