title: Nested form not passing attribute in rails
body: <p>I have many models like <code>Entity</code>, <code>person</code>, <code>stuff</code>, <code>box</code>. All of them in controller Create action has this code <code>@entity = Entity.new(entity_params.merge(user: current_user))</code>.</p>
  
  <p>This code makes perfect association when I make each new Model record. But when I fill nested form from <code>Entity.controller</code> only <code>Entity</code> gets user_id association. All other <code>person</code>, <code>stuff</code> ... has NULL on <code>user_id</code> field.</p>
  
  <p>Don't know how to make this work!</p>