title: Formtastic Confused on Has One Relationships
body: <p>I'm a bit stuck on a 'has_one' and 'belongs_to' relationship and getting it to properly display in Formtastic. I have a person model that has one picture (a profile picture). I want the user to be able to select the picture using radio buttons. So far, I have:</p>
  
  <pre><code>&lt;% form.inputs do %&gt;
    &lt;%= form.input :picture, :as =&gt; :radio, :collection =&gt; @pictures %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>However, this fails (because the foreign key is stored on the 'belongs_to' side of associations in Rails. Any suggestions?</p>