I have a form that has no ActiveRecord model behind it, it is just
composed of random fields like “email_address”, “email_body”, etc.
Even though there is no model, some of these fields are required, and I
would like to use the built-in Rails methods for automatically showing
errors in the form. Unfortunataely, I can only see how to do this if
the form is based on an object whose model extends ActiveRecord. What
is the best way to use all the error message functionaity?