How to set default cookie domain in Rails3

Question

I want to set default cookie domain for my application to ".mydomain.com" to allow cookie session be preserved across subdomains. There are many places showing how to do it in Rails 2.x but these solutions doesn't work for Rails3. Anyone know how can I set it?

Answer 1

I've found the solution. Here it is:

Rails.configuration.session_store :cookie_store, {
  :key    => '_your_app_session',
  :domain => ".domain.com"
}

This should go into config/initializers/session_store.rb. Works great for me.