title: rails - caches_action expire_action
body: <p>I want to expire a cached action and wondered how to generate the correct reference.</p>
  
  <pre><code>#controller
  caches_action :index, :layout =&gt; false
  #generates this fragment which works fine
  views/0.0.0.0:3000/article/someid/posts
  
  #sweeper
  ...
  expire_action article_posts_path(:article_id =&gt; post.article)
  # results in this
  Expired fragment: views//en/article/someid/posts (0.0ms)
  </code></pre>
  
  <p>So this is almost ok, except the host is missing. What do I do that supplies this to the expire_action method?</p>
  
  <p>Thanks in advance.</p>