class Product < ActiveRecord::Base
+ has_many :line_items
+ has_many :orders, :through => :line_items
+
validates_presence_of :title, :description, :image_url
validates_numericality_of :price
validate :price_must_be_at_least_a_penny
def self.find_products_for_sale
find(:all,
- :conditions => "date_available <= now()",
+ :conditions => "date_available <= now() and (date_available_until is null or date_available_until >= now())",
:order => :title)
end