[dbus-python] dynamically export methods

[Colin Walters]

On Tue, May 12, 2009 at 6:39 PM, Olaf Lüke <olaf at uni-paderborn.de> wrote:

> Has someone an idea how to do this? Is there another approach to export
> methods with dbus-python than with decorators that i missed? It is
> pretty painful to create appropriate classes, functions and decorators
> at runtime...

I ran into this problem a while ago...*looks* here's what I came up with:

class UiProxy(dbus.service.Object):
    def __init__(self, factory, bus_name, ui_iface, ui_opath):
        super(UiProxy, self).__init__(dbus.service.BusName(bus_name,
bus=dbus.SessionBus()), ui_opath)
        self.__winfactory = factory
        # This is a disturbing hack.  But it works.
        def RunCommand(self, timestamp, istab, cmd, cwd):
            _logger.debug("Handling RunCommand method invocation ts=%r
cmd=%r cwd=%r)", timestamp, cmd, cwd)
            if istab:
                curwin = self.__winfactory.remote_new_tab(cmd, cwd)
            else:
                raise NotImplementedError('can only create new tabs')
            timestamp = long(timestamp)+1
            if timestamp > 0:
                _logger.debug("presenting with timestamp %r", timestamp)
                curwin.present_with_time(timestamp)
            else:
                curwin.present()
        setattr(UiProxy, 'RunCommand', dbus.service.method(ui_iface,
in_signature='ubass')(RunCommand))

The key here is calling setattr() and using the dbus.service.method
decorator as a wrapper.  There may be a nicer way, but my Python
meta-fu is not strong.