module ActionController::HttpAuthentication::Token

def authentication_request(controller, realm)

Returns nothing.

realm - String realm to use in the header.
controller - ActionController::Base instance for the outgoing response.

Sets a WWW-Authenticate to let the client know a token is desired. 
def authentication_request(controller, realm)
  controller.headers["WWW-Authenticate"] = %(Token realm="#{realm.gsub(/"/, "")}")
  controller.__send__ :render, :text => "HTTP Token: Access denied.\n", :status => :unauthorized
end