From: Michael Guterl <mguterl@...>
Date: 2006-08-16T03:20:27+09:00
Subject: Instance and Related Class Methods

I have a class with a lot of instance methods which are related to
class methods from within the same class.

Example:

class A
  def initialize(start_date, end_date)
    @start_date, @end_date = start_date, end_date
  end

  def total_hours
    A.total_hours(@start_date, @end_date)
  end

  def self.total_hours(start_date, end_date)
    self.sum(:hours, :conditions => between(start_date, end_date))
  end

  def total_incoming
    A.total_incoming(@start_date, @end_date)
  end

  def self.total_incoming(start_date, end_date)
    self.sum(:incoming, :conditions => between(start_date, end_date))
  end

  def total_outgoing
    A.total_outgoing(@start_date, @end_date)
  end

  def self.total_outgoing(start_date, end_date)
    self.sum(:outgoing, :conditions => between(start_date, end_date))
  end
end

Everything works as expected.  However, I am wondering if there is a
more Rubyish way of accomplishing this so I can avoid the repetition.
Any other suggestions are welcome.  Thanks in advance.

Michael Guterl