minor changes - esthetic

devices/__init__.py

         #
         self.callback_list = []
         self.warning_callback = None
+        #
+        self.__previous__ = {}
 
     def receive_callback(self, client, userdata, message):
         self.unpack(message)
         prev_value = self.get(key)
         if key in self.RX_KEYS:
             self[key] = data
+            self.__previous__[key] = prev_value
             # Filter, if needed
             self.unpack_filter(key)
             if prev_value != self.get(key):
     def warning_text(self, data):
         return "default warning text - replace parent warning_text function"
 
+    def previous_value(self, key):
+        self.__previous__.get(key)
+
 
 class shelly(base):
     KEY_OUTPUT_0 = "relay/0"
     KEY_OUTPUT_2 = "output/3"
     KEY_OUTPUT_3 = "output/4"
     KEY_OUTPUT_ALL = "output/all"
+    KEY_OUTPUT_LIST = [KEY_OUTPUT_0, KEY_OUTPUT_1, KEY_OUTPUT_2, KEY_OUTPUT_3]
     #
     TX_TOPIC = 'set'
     TX_TYPE = base.TX_VALUE
     #
     # TX
     #
+    def set_output(self, key, state):
+        if key in self.KEY_OUTPUT_LIST:
+            self.pack(key, state)
+        else:
+            logging.error("Unknown key to set the output!")
+
     def set_output_0(self, state):
         """state: [True, False, 'toggle']"""
         self.pack(self.KEY_OUTPUT_0, state)

function/first_floor_east.py

         self.floorlamp_powerplug.set_output_0(False)
 
     def floorlamp_synchronisation(self, device, key, data):
-        if self.cvi.changed_here(device.topic, key, data):
-            logger.info("Synching \"%s\" floorlamp with main light (%s)", type(self).__name__, str(data))
+        if self.cvi.changed_here(device.topic, key, data) and device.previous_value(key) is not None:
+            logger.info("Syncing \"%s\" floorlamp with main light (%s)", type(self).__name__, str(data))
             self.floorlamp_powerplug.set_output_0(data)
 
     def gui_switch_command_floorlamp(self, device, key, data):
         return rv
 
     def floorlamp_synchronisation(self, device, key, data):
-        if self.cvi.changed_here(device.topic, key, data):
-            logger.info("Synching \"%s\" floorlamp with main light (%s)", type(self).__name__, str(data))
+        if self.cvi.changed_here(device.topic, key, data) and device.previous_value(key) is not None:
+            logger.info("Syncing \"%s\" floorlamp with main light (%s)", type(self).__name__, str(data))
             for device in self.__floorlamp_devices__():
                 device.set_output_0(data)
 

function/ground_floor_west.py

             self.gui_switch_pc_dock.set_feedback(data)
 
     def cd_amplifier_synchronisation(self, device, key, data):
-        if device == self.powerplug_common:
-            if self.cvi.changed_here(device.topic, key, data):
-                logger.info("Setting \"%s\" amplifier: %s", type(self).__name__, data)
-                self.powerplug_common.set_output_0(data)
+        if self.cvi.changed_here(device.topic, key, data) and device.previous_value(key) is not None:
+            logger.info("Syncing \"%s\" amplifier with cd player: %s", type(self).__name__, data)
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_AMPLIFIER, data)
 
     def raspi_amplifier_synchronisation(self, device, key, data):
-        if self.cvi.changed_here(device.topic, key, data):
-            logger.info("Setting \"%s\" amplifier: %s", type(self).__name__, data)
-            self.powerplug_common.set_output_0(data)
+        if self.cvi.changed_here(device.topic, key, data) and device.previous_value(key) is not None:
+            logger.info("Syncing \"%s\" amplifier with raspi player: %s", type(self).__name__, data)
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_AMPLIFIER, data)
 
     def desk_light_switch_action(self, device, key, data):
         if device == self.button_tradfri:
-            logger.info("Toggeling \"%s\" desk light to %s", type(self).__name__, not self.powerplug_common.output_1)
-            self.powerplug_common.set_output_1("toggle")
+            logger.info("Toggeling \"%s\" desk light to %s", type(
+                self).__name__, not self.get(self.KEY_POWERPLUG_AMPLIFIER))
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_AMPLIFIER, "toggle")
         else:
             logger.info("Setting \"%s\" desk light: %s", type(self).__name__, data)
-            self.powerplug_common.set_output_1(data)
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_DESK_LIGHT, data)
 
     def desk_light_set_gui_params_action(self, device, key, data):
         if key == devices.nodered_gui.KEY_BRIGHTNESS:
 
     def amplifier_switch_action(self, device, key, data):
         if device == self.button_tradfri:
-            logger.info("Toggeling \"%s\" amplifier to %s", type(self).__name__, not self.powerplug_common.output_0)
-            self.powerplug_common.set_output_0("toggle")
+            logger.info("Toggeling \"%s\" amplifier to %s", type(self).__name__,
+                        not self.powerplug_common.get(self.KEY_POWERPLUG_AMPLIFIER))
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_AMPLIFIER, "toggle")
         else:
             logger.info("Setting \"%s\" amplifier: %s", type(self).__name__, data)
-            self.powerplug_common.set_output_0(data)
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_AMPLIFIER, data)
 
     def cd_player_switch_action(self, device, key, data):
         if device == self.button_tradfri:
-            logger.info("Toggeling \"%s\" cd_player to %s", type(self).__name__, not self.powerplug_common.output_2)
-            self.powerplug_common.set_output_2("toggle")
+            logger.info("Toggeling \"%s\" cd_player to %s", type(self).__name__,
+                        not self.powerplug_common.get(self.KEY_POWERPLUG_CD_PLAYER))
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_CD_PLAYER, "toggle")
         else:
             logger.info("Setting \"%s\" cd_player: %s", type(self).__name__, data)
-            self.powerplug_common.set_output_2(data)
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_CD_PLAYER, data)
 
     def pc_dock_switch_action(self, device, key, data):
         if device == self.button_tradfri:
-            logger.info("Toggeling \"%s\" pc_dock to %s", type(self).__name__, not self.powerplug_common.output_3)
-            self.powerplug_common.set_output_3("toggle")
+            logger.info("Toggeling \"%s\" pc_dock to %s", type(self).__name__,
+                        not self.powerplug_common.get(self.KEY_POWERPLUG_PC_DOCK))
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_PC_DOCK, "toggle")
         else:
             logger.info("Setting \"%s\" pc_dock: %s", type(self).__name__, data)
-            self.powerplug_common.set_output_3(data)
+            self.powerplug_common.set_output(self.KEY_POWERPLUG_PC_DOCK, data)
 
     def device_chooser_action(self, device, key, data):
         if device == self.main_light_shelly:
         if state == self.STATE_ACTIVE_DEVICE_MAIN_LIGHT:
             return self.main_light_shelly.output_0
         elif state == self.STATE_ACTIVE_DEVICE_DESK_LIGHT:
-            return self.powerplug_common.output_1
+            return self.powerplug_common.get(self.KEY_POWERPLUG_DESK_LIGHT)
         elif state == self.STATE_ACTIVE_DEVICE_AMPLIFIER:
-            return self.powerplug_common.output_0
+            return self.powerplug_common.get(self.KEY_POWERPLUG_AMPLIFIER)
 
     def choose_next_device(self, device=None, key=None, data=None):
         if self.active_device_state is not None: