Optional string in Rails route

I want to add an optional string to an URL. I've tried this:

map ":category/p:id(/:title)" => ...

The title parameter should be op开发者_运维知识库tional, so that the user can insert a optional title or leave it. Sadly this does not work. Any ideas?

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If I remember correctly, it depends on what version of Ruby on Rails you are using.

Rails 3

  
    match ':category/p:id(/:title)', :to => 'category#edit'
  

Rails 2

  
    map.connect ':category/p:id/:title, :controller => 'category', :action => 'edit', :title => 'default title'