dbus-objects

DBus objects implementation on top of the Python type system.

Object declarations will be introspected and the equivalent DBus signature automatically generated. This makes it incredible easy to develop DBus object providers ("servers"), especially if you are already writing typed Python!

Integrations:

• jeepney (blocking IO and trio backends)

import random

from typing import List

import dbus_objects
import dbus_objects.integration.jeepney


class ExampleObject(dbus_objects.DBusObject):
    def __init__(self):
        super().__init__(default_interface_root='io.github.ffy00.dbus_objects.example')
        self._bets = []
        self._name = 'something'

    @dbus_objects.dbus_method()
    def ping(self) -> str:
        return 'Pong!'

    @dbus_objects.dbus_method()
    def print(self, msg: str) -> None:
        print(msg)

    @dbus_objects.dbus_method()
    def sum(self, a: int, b: int) -> int:
        return a + b

    @dbus_objects.dbus_method()
    def save_bet(self, number: int) -> None:
        self._bets.append(number)

    @dbus_objects.dbus_method()
    def get_bets(self) -> List[int]:
        return self._bets

    @dbus_objects.dbus_method()
    def lotery(self) -> int:
        winner = random.choice(self._bets)
        self._bets = []
        return winner

    @dbus_objects.dbus_property()
    def name(self) -> str:
        return self._name

    @name.setter
    def name(self, value: str):
        self._name = value
        self.name_updated(value)

    name_updated = dbus_objects.dbus_signal(new_name=str)


server = dbus_objects.integration.jeepney.BlockingDBusServer(
    bus='SESSION',
    name='io.github.ffy00.dbus-objects',
)
server.register_object('/io/github/ffy00/dbus_objects/example', ExampleObject())

server.listen()

This example will generate the following server topology:

paths
 /
    org.freedesktop.DBus.Introspectable
       Introspect
    org.freedesktop.DBus.Peer
        Ping
 /io
    org.freedesktop.DBus.Introspectable
       Introspect
    org.freedesktop.DBus.Peer
        Ping
 /io/github
    org.freedesktop.DBus.Introspectable
       Introspect
    org.freedesktop.DBus.Peer
        Ping
 /io/github/ffy00
    org.freedesktop.DBus.Introspectable
       Introspect
    org.freedesktop.DBus.Peer
        Ping
 /io/github/ffy00/dbus_objects
    org.freedesktop.DBus.Introspectable
       Introspect
    org.freedesktop.DBus.Peer
        Ping
 /io/github/ffy00/dbus_objects/example
     io.github.ffy00.dbus_objects.example.ExampleObject
        GetBets
        Lotery
        Ping
        Print
        SaveBet
        Sum
     org.freedesktop.DBus.Introspectable
        Introspect
     org.freedesktop.DBus.Peer
        Ping
     org.freedesktop.DBus.Properties
         Get
         GetAll
         Set

And, for eg., the following DBus introspection XML for /io/github/ffy00/dbus_objects/example:

<!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="io.github.ffy00.dbus_objects.example.ExampleObject">
		<method name="Ping">
			<arg direction="out" type="s" />
		</method>
		<method name="Print">
			<arg direction="in" type="s" name="msg" />
		</method>
		<method name="Sum">
			<arg direction="in" type="i" name="a" />
			<arg direction="in" type="i" name="b" />
			<arg direction="out" type="i" />
		</method>
		<method name="SaveBet">
			<arg direction="in" type="i" name="number" />
		</method>
		<method name="GetBets">
			<arg direction="out" type="ai" />
		</method>
		<method name="Lotery">
			<arg direction="out" type="i" />
		</method>
		<property name="Name" type="s" access="readwrite" />
		<signal name="NameUpdated">
			<arg type="s" name="new_name" />
		</signal>
	</interface>
	<interface name="org.freedesktop.DBus.Properties">
		<method name="Get">
			<arg direction="in" type="s" name="interface_name" />
			<arg direction="in" type="s" name="property_name" />
			<arg direction="out" type="v" />
		</method>
		<method name="Set">
			<arg direction="in" type="s" name="interface_name" />
			<arg direction="in" type="s" name="property_name" />
			<arg direction="in" type="v" name="value" />
		</method>
		<method name="GetAll">
			<arg direction="in" type="s" name="interface_name" />
			<arg direction="out" type="a{sv}" />
		</method>
	</interface>
	<interface name="org.freedesktop.DBus.Peer">
		<method name="Ping" />
	</interface>
	<interface name="org.freedesktop.DBus.Introspectable">
		<method name="Introspect">
			<arg direction="out" type="s" name="xml" />
		</method>
	</interface>
</node>

License

MIT