title: Ruby on Rails Paper clip old files name issue
body: <p>I'm using Rails 4 and after added paper clip initializer code  to initialize the user files name by user ID to give every file different name  using this code </p>
  
  <p><strong>In the initialize file</strong></p>
  
  <pre><code># initializers images names by the model id (:id)
  Paperclip.interpolates :parent_id do |a, s|
      a.instance.contract.id
  end
  </code></pre>
  
  <p><strong>In the model</strong> </p>
  
  <pre><code>  has_attached_file :photo ,
                      :url =&gt; "/system/files/users/:basename_:id.:extension",
                      :path =&gt; ":rails_root/public/system/files/users/:basename_:id.:extension"
  </code></pre>
  
  <p>Now it's work well by give the file his basename_fileID.file extension</p>
  
  <p>but I notes that I was missed all the old files links because the new link will search about the file contain the basename and fileID something like that "<strong>image_1.jpeg</strong>" but the old link search about  basename only  something like "<strong>image.jpeg</strong>"</p>
  
  <p>so how I can solve it in Rails without change my old files name on server ??</p>
  
  <p>Is there's some thing in Rails 4 allow me to inform the links  to get the old path in some cases or not ??</p>