Trigger an EntityUpdateEvent when an entity state changes

platypush/entities/_engine.py

@@ -7,6 +7,9 @@ from typing import Iterable, List
 from sqlalchemy import and_, or_
 from sqlalchemy.orm import Session
 
+from platypush.context import get_bus
+from platypush.message.event.entities import EntityUpdateEvent
+
 from ._base import Entity
 
 
@@ -130,3 +133,6 @@ class EntitiesEngine(Thread):
             entities = self._merge_entities(entities, existing_entities)  # type: ignore
             session.add_all(entities)
             session.commit()
+
+        for entity in entities:
+            get_bus().post(EntityUpdateEvent(entity=entity))

platypush/message/event/entities.py

@@ -0,0 +1,19 @@
+from typing import Union
+
+from platypush.entities import Entity
+from platypush.message.event import Event
+
+
+class EntityUpdateEvent(Event):
+    """
+    This even is triggered whenever an entity of any type (a switch, a light,
+    a sensor, a media player etc.) updates its state.
+    """
+
+    def __init__(self, entity: Union[Entity, dict], *args, **kwargs):
+        if isinstance(entity, Entity):
+            entity = entity.to_json()
+        super().__init__(entity=entity, *args, **kwargs)
+
+
+# vim:sw=4:ts=4:et: