title: Rails, destroy if blank
body: <p>This might sound odd, but is there a 'Rails way' to have a model destroyed if a certain attribute is blank? Say I have a model like <code>tags</code> with just a name attribute or something, if the user edits the tag and deletes all the text out of the name field in the form I'd like the model to just be deleted.</p>
  
  <p>I'm aware of the <code>reject_if</code> method, but that doesn't seem to work.</p>