fix(cache): clean cache on object deletion

Remove cached properties of deleted objects to reduce cache size
and prevent cache corruption

Author: Jo-Byr

src/trame_vtk/modules/common/serve/trame-vtk.js

@@ -1,6 +1,11 @@
 PROP_CACHE = {}
 
 
+def remove_from_cache(obj_id):
+    if obj_id in PROP_CACHE:
+        del PROP_CACHE[obj_id]
+
+
 def get_cached_property(obj_id, prop):
     return PROP_CACHE.get(obj_id, {}).get(prop, None)
 

src/trame_vtk/modules/vtk/serializers/cache.py

@@ -1,5 +1,7 @@
 import logging
+import vtk
 
+from .cache import remove_from_cache
 from .registry import class_name, SERIALIZERS
 from .widgets import handle_widget
 
@@ -9,11 +11,17 @@
 
 # Keep track of which warnings have been printed
 NO_SERIALIZER_FOR_INSTANCE = {}
+DELETE_CALLBACKS = []
 
 
 def serialize(parent, instance, instance_id, context, depth):
     instance_type = class_name(instance)
     serializer = SERIALIZERS[instance_type] if instance_type in SERIALIZERS else None
+    if instance_id not in DELETE_CALLBACKS:
+        instance.AddObserver(
+            vtk.vtkCommand.DeleteEvent, lambda *a, **k: remove(instance_id)
+        )
+        DELETE_CALLBACKS.append(instance_id)
 
     if serializer:
         return serializer(parent, instance, instance_id, context, depth)
@@ -26,5 +34,10 @@ def serialize(parent, instance, instance_id, context, depth):
     return None
 
 
+def remove(instance_id):
+    remove_from_cache(instance_id)
+    DELETE_CALLBACKS.remove(instance_id)
+
+
 def serialize_widget(dict_out, widget):
     handle_widget(dict_out, widget)