title: Rails 4 form without model and database
body: <p>I want to create a form in HAML, but I don't have a model or database table. The form should just send its fields via <code>POST</code> to an action and I will handle it from there.
  As far as I could tell, <code>form_for</code> has to have a <code>record</code>.</p>
  
  <p>What is the current best practice to do this?</p>