local barexml = [=[<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object
    Introspection 1.0//EN"
    "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
    <node>
      <interface name="org.freedesktop.DBus.Introspectable">
        <method name="Introspect">
          <arg name="xml_data" type="s" direction="out"/>
        </method>
      </interface>
    </node>
]=]

local function _retxml(nextnode)
   return [=[<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object
    Introspection 1.0//EN"
    "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
    <node>
      <interface name="org.freedesktop.DBus.Introspectable">
        <method name="Introspect">
          <arg name="xml_data" type="s" direction="out"/>
        </method>
      </interface>
      <node name="]=] .. nextnode .. [=[" />
    </node>
]=]
end

local function _introspect_cb(data, text)
   if data.member == "Introspect" then
      local nextnode
      if data.path == "/" then
	 nextnode = "org"
      elseif data.path == "/org" then
	 nextnode = "freedesktop"
      elseif data.path == "/org/freedesktop" then
	 nextnode = "Notifications"
      else
	 return "s", barexml
      end
      return "s", _retxml(nextnode)
   end
end

local function _property_cb(data, text)
end
   
dbus.connect_signal("", _introspect_cb)
dbus.connect_signal("org.freedesktop.DBus.Properties", _property_cb)