Update layout.py

Author: shawncrawley

src/reactpy/core/layout.py

@@ -277,10 +277,17 @@ def _render_model_attributes(
 
         model_event_handlers = new_state.model.current["eventHandlers"] = {}
         for event, handler in handlers_by_event.items():
-            if event in old_state.targets_by_event:
-                target = old_state.targets_by_event[event]
+            if isinstance(handler, str):
+                target = handler
+                prevent_default = False
+                stop_propagation = False
             else:
-                target = uuid4().hex if handler.target is None else handler.target
+                prevent_default = handler.prevent_default
+                stop_propagation = handler.stop_propagation
+                if event in old_state.targets_by_event:
+                    target = old_state.targets_by_event[event]
+                else:
+                    target = uuid4().hex if handler.target is None else handler.target
             new_state.targets_by_event[event] = target
             self._event_handlers[target] = handler
             model_event_handlers[event] = {
@@ -301,7 +308,14 @@ def _render_model_event_handlers_without_old_state(
 
         model_event_handlers = new_state.model.current["eventHandlers"] = {}
         for event, handler in handlers_by_event.items():
-            target = uuid4().hex if handler.target is None else handler.target
+            if isinstance(handler, str):
+                target = handler
+                prevent_default = False
+                stop_propagation = False
+            else:
+                target = uuid4().hex if handler.target is None else handler.target
+                prevent_default = handler.prevent_default
+                stop_propagation = handler.stop_propagation
             new_state.targets_by_event[event] = target
             self._event_handlers[target] = handler
             model_event_handlers[event] = {