Create new kalman_combinator component (#2965)

esphome/core/entity_helpers.py

@@ -5,27 +5,49 @@ from esphome.const import CONF_ID
 
 def inherit_property_from(property_to_inherit, parent_id_property):
     """Validator that inherits a configuration property from another entity, for use with FINAL_VALIDATE_SCHEMA.
-
     If a property is already set, it will not be inherited.
-
     Keyword arguments:
-    property_to_inherit -- the name of the property to inherit, e.g. CONF_ICON
-    parent_id_property -- the name of the property that holds the ID of the parent, e.g. CONF_POWER_ID
+    property_to_inherit -- the name or path of the property to inherit, e.g. CONF_ICON or [CONF_SENSOR, 0, CONF_ICON]
+                           (the parent must exist, otherwise nothing is done).
+    parent_id_property -- the name or path of the property that holds the ID of the parent, e.g. CONF_POWER_ID or
+                          [CONF_SENSOR, 1, CONF_POWER_ID].
     """
 
+    def _walk_config(config, path):
+        walk = [path] if not isinstance(path, list) else path
+        for item_or_index in walk:
+            config = config[item_or_index]
+        return config
+
     def inherit_property(config):
-        if property_to_inherit not in config:
+        # Split the property into its path and name
+        if not isinstance(property_to_inherit, list):
+            property_path, property = [], property_to_inherit
+        else:
+            property_path, property = property_to_inherit[:-1], property_to_inherit[-1]
+
+        # Check if the property to inherit is accessible
+        try:
+            config_part = _walk_config(config, property_path)
+        except KeyError:
+            return config
+
+        # Only inherit the property if it does not exist yet
+        if property not in config_part:
             fconf = fv.full_config.get()
 
             # Get config for the parent entity
-            path = fconf.get_path_for_id(config[parent_id_property])[:-1]
-            parent_config = fconf.get_config_for_path(path)
+            parent_id = _walk_config(config, parent_id_property)
+            parent_path = fconf.get_path_for_id(parent_id)[:-1]
+            parent_config = fconf.get_config_for_path(parent_path)
 
             # If parent sensor has the property set, inherit it
-            if property_to_inherit in parent_config:
+            if property in parent_config:
                 path = fconf.get_path_for_id(config[CONF_ID])[:-1]
-                this_config = fconf.get_config_for_path(path)
-                this_config[property_to_inherit] = parent_config[property_to_inherit]
+                this_config = _walk_config(
+                    fconf.get_config_for_path(path), property_path
+                )
+                this_config[property] = parent_config[property]
 
         return config