gistfile1.rb

# initial idea for state(or step #)-based validation
# for the model below, it would only run those validations when instance_model#step == "initial" or nil
 
class ActiveRecord::Base
  def self.validate_on_step(attribute, &block)
    attribute, step_attribute = attribute.to_s, "step"
    self.send :attr_accessor, step_attribute unless self.respond_to?(step_attribute)

    with_options(:if => lambda {|w| (w.send(step_attribute) == attribute) || (w.send(step_attribute).nil?) }) do |validating_model|
      yield(validating_model)
    end
  end
end


class User < ActiveRecord::Base
  validate_on_step :initial do |v|
    v.validates_presence_of :title
  end
end