listing_highlight.rb

# Before, I was overriding the initialize method to set the run_date.
# This is how I'm doing it now:

class ListingHighlight < ActiveRecord::Base

  before_validation :assign_run_date
  validates_presence_of :run_date, :on => :create

  def run_date=( value )
    write_attribute :run_date, some_date_method(value)
  end

  def run_date
    read_attribute :run_date or write_attribute(:run_date, some_date_method)
  end

  protected

  def assign_run_date
    run_date
  end

end