Rails Deprecation Logger

deprecation_logger.rb

# Stick this in config/initializers and restart your app to install
# Then you can log your deprecations to log/deprecations.log quickly and easily

# To log with this, just call:
# DeprecationLogger.notify('StringDescriptionOfMethod', DeprecationLogger.caller_method) 

class DeprecationLogger < Logger

  @logfile = File.open(Rails.root.join('log','deprecations.log'), 'a')
  @logfile.sync = true

  def format_message(severity,timestamp,progname,msg)
    "#{timestamp.to_formatted_s(:db)} #{msg}\n"
  end

  def self.log
    self.new(@logfile)
  end

  def self.notify(method, called_by)
    self.log.info("Deprecated method #{method} was called \n  #{called_by}")
  end

  def self.caller_method(depth=1)
    parse_caller(caller(depth+1).first)
  end

  private
    def self.parse_caller(at)
      if /^(.+?):(\d+)(?::in `(.*)')?/ =~ at
        file   = Regexp.last_match[1]
        line   = Regexp.last_match[2].to_i
        method = Regexp.last_match[3]
        "Method: #{method} @ #{file} : #{line}"      
      end
    end
end