Event Model

scope :current, where(:current=>true}

validate :only_one_current

protected


def only_one_current
 errors.add_to_base("Only one event can be current") if Event.current.reject{|c| c.eql?(self)}.size>0 
end

def before_create
 if self.current?
  Event.current.last.update_attribute("current", false)
 end
end

Routes

get "current_event" => "events#current_event"  
get "current_event/days" => "days#current_days"
get "current_event/days/registrants" => "registrants#current_registrants"
get "current_event/days/registrants" => "registrants#search"
get "current_event/days/registrants" => "registrants#all_schedules"
get "current_event/days/registrants" => "registrants#schedule"
get "current_event/days/registrants" => "registrants#edit_attendance"
post "current_event/days/registrants" => "registrants#update_attendance"