Rooting constraints

#lib/role_constraint.rb

class RoleConstraint
  def initialize(*roles)
    @roles = roles
  end

  def matches?(request)
    @roles.include? request.env['warden'].user.try(:role)
  end
end

#config/routes.rb
root :to => 'admin#index', :constraints => RoleConstraint.new(:admin) #matches this route when the current user is an admin
root :to => 'sites#index', :constraints => RoleConstraint.new(:user) #matches this route when the current user is an user
root :to => 'home#index' #matches this route when the above two matches don't pass