gistfile1.rb

class Admin::AuditsController < ApplicationController
  def create
    @audit = Audit.new params[:audit]

    if @audit.valid?
      # ...
    else
      render :action => 'new'
    end
  end
end

gistfile2.txt

class Audit < ActiveRecord::RecordWithoutBase
  validates_format_of :start_date, :with => ...
  validates_format_of :end_date, :with => ...

  def versions
    accounts= Account.with_role(Role.find_by_name("admin"))

    VestalVersions::Version.order("created_at desc").where(:user_id => accounts, :created_at => start_date..end_date)
  end
end