class Link < Item field :url validates :url, :presence => true, :format => /^(http|https):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(([0-9]{1,5})?\/.*)?$/ix before_validation :add_http def link ApplicationController.helpers.link_to(self.name, self.url) end protected def add_http unless self.url[/^http:\/\//] || self.url[/^https:\/\//] self.url = 'http://' + self.url end end end