class Product < ActiveRecord::Base
    validates_presence_of :title , :description , :image_url
    validates_numericality_of :price
    validates_uniqueness_of :title
    validates_format_of :image_url ,
                        :with =>%r{\.(gif|jpg|png)$}i,
                        :message => "URL - Изображения только формата gif,jpg,png !"
    protected 
 def validate
         errors.add(:price , "Цена должна быть не менее 0.01")
       if price <= 0.01
        end
    end
  def self.find_products_for_sale
    find(:all ,:order=>"title")
  end
end

<img class = "list-image" src = "<%= product.image_url%>">

#product-list .list-image {
  width:        60px;
  height:       70px;
}