gistfile1.rb

def index
  if stale?(:last_modified => @clients.maximum("updated_at"), :etag => @clients)
    respond_with @clients.as_json(:methods => [:emails_count, :phones_count, :communications_count])
  end
end

def show
  if stale?(@client)
    respond_with @client.to_json(:include => {
      :emails => {:limit => 10}, 
      :phones => {:limit => 10}, 
      :user => {}, 
      :communications => {:include => :clients}
    })
  end
end