title: MVC model design / inheritance
body: <p>Forgive the vague title, I wasn't sure how to describe it.</p>
  
  <p>If you have a generic model "Archive", how do you show different views/forms based on a user selected 'type'?</p>
  
  <p>For example, the user creates a new "Archive", then gets the choice of video, book, audio etc. From there they get different forms based on the archive type.</p>
  
  <p>Or would it be better to split them into different models - Video, Book, Audio? </p>
  
  <p>Or can models inherit (like Video extends Archive). I guess this is basic OOP / classes, but have no idea how to apply that here.</p>
  
  <p>Examples from any MVC framework are welcome!</p>