gistfile1.rb

class NewsItem < ActiveRecord::Base
  validates_presence_of(:date, :headline, :body)

  def date
    @date.strftime("%Y-%m-%d") if @date
  end

  def date=(input)
    case input
    when String
      puts "date is a string"
      @date = Date.parse(input)
    when Date
      puts "date is a date"
      @date = input
    when NilClass
      puts "date is nil"
      @date = nil
    else
      raise("Unexpected date: #{input}")
    end
  end
end

gistfile2.txt

rails console
Loading development environment (Rails 3.0.0.rc2)
ruby-1.9.2-p0 > n = NewsItem.new
 => #<NewsItem id: nil, headline: nil, byline: nil, body: nil, created_at: nil, updated_at: nil, date: nil>
ruby-1.9.2-p0 > n.date = '2008-10-20'
date is a string
 => "2008-10-20"
ruby-1.9.2-p0 > n.date
 => "2008-10-20"
ruby-1.9.2-p0 > n
 => #<NewsItem id: nil, headline: nil, byline: nil, body: nil, created_at: nil, updated_at: nil, date: nil>
ruby-1.9.2-p0 >  

# why is date stil nil?