build_cookie

# File actionpack/lib/action_controller/session/cookie_store.rb, line 129
        def build_cookie(key, value)
          case value
          when Hash
            domain  = "; domain="  + value[:domain] if value[:domain]
            path    = "; path="    + value[:path]   if value[:path]
            # According to RFC 2109, we need dashes here.
            # N.B.: cgi.rb uses spaces...
            expires = "; expires=" + value[:expires].clone.gmtime.
              strftime("%a, %d-%b-%Y %H:%M:%S GMT") if value[:expires]
            secure = "; secure" if value[:secure]
            httponly = "; HttpOnly" if value[:httponly]
            value = value[:value]
          end
          value = [value] unless Array === value
          cookie = Rack::Utils.escape(key) + "=" +
            value.map { |v| Rack::Utils.escape(v) }.join("&") +
            "#{domain}#{path}#{expires}#{secure}#{httponly}"
        end