We're using this to build internal services - I'm currently wondering if there's a best practice for taking querystring params and mapping them to an ActiveReco

We're using this to build internal services - I'm currently wondering if there's a best practice for taking querystring params and mapping them to an ActiveRecord query. Obviously, it's possible to build a "Searchable" module/class, but I wondered if anyone has already solved this problem? Eg, pagingation, querying on date-ranges, ordering, filtering etc.