title: dynamically assign class in haml
body: <p>Hi I have the following haml:</p>
  
  <pre><code>.btn-group-wrap{style:'text-align:center;'}
    .btn-group{style: 'display: inline-block; text-align:center; width:inherit;'}
      =link_to "All Users", users_path, class: 'btn active'
      =link_to "Search", '#', class:'btn'
  </code></pre>
  
  <p>I want to be able to toggle back and forth between <code>active</code> class for each of the links. ie if <code>params[:controller] == "users"</code> then I want that to be <code>active</code>. If <code>params[:controller] =="search"</code> then it will make the users class just <code>'btn'</code> and Search <code>'btn active'</code>.</p>