How to pass a flexible number of ids into a controller in Rails?

Question

I'd like to display a comparison page so user can compare the properties of several objects in my database. Any number of objects can be compared. I'd also like it to be bookmarkable (so a 'get').

How should I structure my URL / route for the controller?

Something like /foo_compare/1_5_22 where I split the ids into 1, 5 and 22 in the controller?

Maybe /foo_compare/1/5/22, but how would I set up the route?

Answer 1

I'd prefer

/compare?a=1&b=5&c=22

The 1_5_22 is just fugly, and I think that

/compare/1/5/22

is a very non-RESTful route.

Answer 2

# routes.rb
map.connect 'compare/*:comparisons', :controller => 'whatever', :action => 'you_name_it'

# in the controller
ids = params[:comparisons].split('/')

This maps to e.g. /compare/1/5/203.