database-less models in your controllers/views

model.rb

# sometimes you want a non-db backed model in rails.  you can put this in
# lib/model.rb and then:
#
# file: app/models/signup.rb
#
#  class Signup < Model
#    validates_presence_of :email
#  end
#

  class Model
    include ActiveModel::Validations
    include ActiveModel::Conversion
    extend ActiveModel::Naming

    def model_name
      self < Model ? self.name.gsub('Model::', '') : super
    end

    def initialize(attributes = {})
      unless attributes.blank?
        attributes.each{|name, value| send("#{ name }=", value)}
      end
    end

    def persisted?
      false
    end
  end