title: Rails, Formtastic: checkboxes, but just allow to check ONE
body: <p>I have a form and a group of checkboxes. But I want the user to be able to only check ONE value, never more than one. </p>
  
  <p>This is what I have and it works for more than one value; it's on a has many through association. But now the clients wants to check only ONE, not more than one. I don't want to make changes to the DB or the associations because this client might change her mind later.</p>
  
  <pre><code>&lt;%= f.collection_check_boxes(:community_partner_organization_ids, CommunityPartnerOrganization.order('name'), :id, :name, {}, {:class =&gt; 'checkbox'}) {|input| input.label(:class =&gt; 'checkbox') { input.check_box + input.text }} %&gt;
  </code></pre>