Question

I want to load a collection only once from the db so I don’t need to do it on each request or store it in cache.

Where can I do this in Rails 3? At one point in the application start cycle?

Also, how will this collection be made available through the site?

Answer 1

It might be simple enough to have a cached class method. This sort of thing comes in handy for the contents of drop-down lists which changes so infrequently it’s as good as static:

class Country
  def self.cached_list
    @cached_list ||= self.all
  end
end

Keep in mind that class instance variables will persist for the life-span of the class itself. In the development environment this is one request, but in production this is all requests made to the same process.