class ActiveRecord::Base
  alias _method_missing_without_singleton_validations method_missing
  def method_missing(m, *args, &block)
    if (match = /^(validates_(.*))$/.match(m.to_s)) &&
       self.class.respond_to?(match[0])
        (class << self; self; end).send(match[0],*args,&block)
    else
      _method_missing_without_singleton_validations(m,*args,&block)
    end
  end

  #alias_method_chain :method_missing, :singleton_validations
end

module ActiveSupport::Callbacks
  def run_callbacks_with_singleton_class(kind, options = {}, &block)
    y = run_callbacks_without_singleton_class(kind, options, &block)
    x = (class << self; self; end).send("#{kind}_callback_chain").run(self, options, &block)
    x.concat(y)
  end
  alias_method_chain :run_callbacks, :singleton_class
end