Restful resources with a somewhat complex scheme

Hi guys, I'm trying to figure out the routing of my application but unfortunately I'm having some problems.

I have a polymorphic association where ads are related to 5 different kinds of resources (videos, prints, radios, banners and concepts), where every :ad has_one :resource. Ads belong_to and can be filtered by contest, the contest object has a permalink.

This is the routing scheme I came up with:

ads/index => collection of all ads ads/contest_permalink => collection of all ads of a contest ads/videos => collection of all videos ads/contest_permalink/videos => collection of all videos of a specific contest ads/contest_permalink/videos/ads_permalink => specific ad

The reason behind this choice is that contest permalink normally is the name of a famous company, and ad permalinks are a common SEO practice (both things are very good SEO wise). This way a specific ad is going to be something like ads/nike/videos/foobar where nike is the contest permalink, and foobar is the ad permalink. Both permalinks are of course unique keys.

This design satisfies me, it's both restful and the urls are clear enough to be guessable.

My problem and my question is about the implementation. If I had to implement it following the data scheme it would be something like map.resources :ads, :has_one => [ :video, :print, ... ] but of course this won't do the trick: I should overwrite Ad.to_param to reproduce the contest permalink which is not unique inside the ads scope (of course), and the resource is without id (and AFAIK we just have settable url prefixes, I can't append something like a permalink). Is there a way that let's me use a generic string filter on the ads resource and still have the specific ad type (say, Video) have a to_param that maps on the permalink ? I know that I can still have named routes, but I would really like to have all the goodness that comes with map.resources. I believe that this is a decent restful architecture (but I'm happy if someone comes up with a better solution), I find it kind of weird that rails asks me to define everything by hand - but maybe I'm asking the framework too much :slight_smile:

TIA,   ngw