gistfile1.rb

class FooBarTransactionFailed < ActiveRecord::RecordInvalid
  def initialize(foo, bar)
    @foo, @bar = foo, bar
  end
end

begin
  transaction do
    foo = FooClass.create(:blah => 'blah')
    bar = BarClass.create(:bleh => 'bleh')

    raise FooBarTransactionFailed.new(foo, bar) if (foo.new_record? && bar.new_record?)
    return foo, bar, 'success'
  end
rescue FooBarTransactionFailed => e
  return e.foo, e.bar, 'error'
end