Moved card visibility logic out of the Entity class and into a VisibilityABC. Then made the Group class inherit the VisibilityABC. No duplication of code now. This is definitely better.

homeassistant/bootstrap.py

@@ -20,7 +20,7 @@ import homeassistant
 import homeassistant.loader as loader
 import homeassistant.components as core_components
 import homeassistant.components.group as group
-from homeassistant.helpers.entity import Entity
+from homeassistant.helpers.entity import VisibilityABC
 from homeassistant.const import (
     EVENT_COMPONENT_LOADED, CONF_LATITUDE, CONF_LONGITUDE,
     CONF_TEMPERATURE_UNIT, CONF_NAME, CONF_TIME_ZONE, TEMP_CELCIUS,
@@ -208,7 +208,7 @@ def process_ha_core_config(hass, config):
         if key in config:
             setattr(hass.config, attr, config[key])
 
-    Entity.visibility.update(config.get('visibility', {}))
+    VisibilityABC.visibility.update(config.get('visibility', {}))
 
     if CONF_TEMPERATURE_UNIT in config:
         unit = config[CONF_TEMPERATURE_UNIT]

homeassistant/components/group.py

@@ -7,7 +7,7 @@ Provides functionality to group devices that can be turned on or off.
 
 import homeassistant as ha
 from homeassistant.helpers import generate_entity_id
-from homeassistant.helpers.entity import Entity
+from homeassistant.helpers.entity import VisibilityABC
 import homeassistant.util as util
 from homeassistant.const import (
     ATTR_ENTITY_ID, ATTR_FRIENDLY_NAME, STATE_ON, STATE_OFF,
@@ -111,12 +111,8 @@ def setup(hass, config):
     return True
 
 
-class Group(object):
+class Group(VisibilityABC):
     """ Tracks a group of entity ids. """
-    # pylint: disable=too-many-instance-attributes
-
-    visibility = Entity.visibility
-    _hidden = False
 
     def __init__(self, hass, name, entity_ids=None, user_defined=True):
         self.hass = hass
@@ -220,24 +216,6 @@ class Group(object):
                 self.hass.states.set(
                     self.entity_id, group_off, self.state_attr)
 
-    @property
-    def hidden(self):
-        """
-        Returns the official decision of whether the entity should be hidden.
-        Any value set by the user in the configuration file will overwrite
-        whatever the component sets for visibility.
-        """
-        if self.entity_id is not None and \
-                self.entity_id.lower() in self.visibility:
-            return self.visibility[self.entity_id.lower()] == 'hide'
-        else:
-            return self._hidden
-
-    @hidden.setter
-    def hidden(self, val):
-        """ Sets the suggestion for visibility. """
-        self._hidden = bool(val)
-
 
 def setup_group(hass, name, entity_ids, user_defined=True):
     """ Sets up a group state that is the combined state of

homeassistant/helpers/entity.py

@@ -12,7 +12,40 @@ from homeassistant.const import (
     STATE_OFF, DEVICE_DEFAULT_NAME, TEMP_CELCIUS, TEMP_FAHRENHEIT)
 
 
-class Entity(object):
+class VisibilityABC(object):
+    """
+    Abstract Class for including visibility logic. This class includes the
+    necessary methods and properties to consider a visibility suggestion form
+    the component and then determine visibility based on the options in the
+    configuration file. When using this abstract class, the value for the
+    hidden property must still be included in the attributes disctionary. The
+    Entity class takes care of this automatically.
+    """
+
+    entity_id = None
+    visibility = {}
+    _hidden = False
+
+    @property
+    def hidden(self):
+        """
+        Returns the official decision of whether the entity should be hidden.
+        Any value set by the user in the configuration file will overwrite
+        whatever the component sets for visibility.
+        """
+        if self.entity_id is not None and \
+                self.entity_id.lower() in self.visibility:
+            return self.visibility[self.entity_id.lower()] == 'hide'
+        else:
+            return self._hidden
+
+    @hidden.setter
+    def hidden(self, val):
+        """ Sets the suggestion for visibility. """
+        self._hidden = bool(val)
+
+
+class Entity(VisibilityABC):
     """ ABC for Home Assistant entities. """
     # pylint: disable=no-self-use
 
@@ -20,8 +53,6 @@ class Entity(object):
     # The properties and methods here are safe to overwrite when inherting this
     # class. These may be used to customize the behavior of the entity.
 
-    _hidden = False  # suggestion as to whether the entity should be hidden
-
     @property
     def should_poll(self):
         """
@@ -83,7 +114,6 @@ class Entity(object):
 
     hass = None
     entity_id = None
-    visibility = {}
 
     def update_ha_state(self, force_refresh=False):
         """
@@ -130,24 +160,6 @@ class Entity(object):
     def __repr__(self):
         return "<Entity {}: {}>".format(self.name, self.state)
 
-    @property
-    def hidden(self):
-        """
-        Returns the official decision of whether the entity should be hidden.
-        Any value set by the user in the configuration file will overwrite
-        whatever the component sets for visibility.
-        """
-        if self.entity_id is not None and \
-                self.entity_id.lower() in self.visibility:
-            return self.visibility[self.entity_id.lower()] == 'hide'
-        else:
-            return self._hidden
-
-    @hidden.setter
-    def hidden(self, val):
-        """ Sets the suggestion for visibility. """
-        self._hidden = bool(val)
-
 
 class ToggleEntity(Entity):
     """ ABC for entities that can be turned on and off. """