module ActionDispatch::Http::URL

def full_url_for(options)
  host     = options[:host]
  protocol = options[:protocol]
  port     = options[:port]
  unless host
    raise ArgumentError, "Missing host to link to! Please provide the :host parameter, set default_url_options[:host], or set :only_path to true"
  end
  build_host_url(host, port, protocol, options, path_for(options))
end