Safe attachments

attachment_helper.rb

# in AttachmentsHelper:
def safe_attachment_path(attachment, size=nil)
  retrieve_attachment_path(attachment.id, attachment.original_name, :size => size)
end

# and then have a route
match '/files/:id/:filename' => 'attachments#retrieve', :as => :retrieve_attachment

# and a controller action
def retrieve
  path = params[:size] ? resource.file_url(params[:size]) : resource.file_url
    redirect_to path
  else
    redirect_to back, :notice => 'Cannot find resource'
  end
end