Just trigger if attribute is None instead of passing inaccurate value

jdaviz/core/template_mixin.py

@@ -2026,7 +2026,7 @@ def __init__(self, plugin, items, selected, multiselect=None, selected_has_subre
         self.hub.subscribe(self, SubsetUpdateMessage,
                            handler=lambda msg: self._update_subset(msg.subset, msg.attribute))
         self.hub.subscribe(self, SubsetCreateMessage,
-                           handler=lambda msg: self._update_subset(msg.subset, attribute="type"))
+                           handler=lambda msg: self._update_subset(msg.subset))
         self.hub.subscribe(self, SubsetDeleteMessage,
                            handler=lambda msg: self._delete_subset(msg.subset))
         self.hub.subscribe(self, SubsetRenameMessage,
@@ -2104,7 +2104,8 @@ def _update_subset(self, subset, attribute=None):
                 self.items = self.items + [self._subset_to_dict(subset)]  # noqa
         else:
             # 'type' can be passed manually rather than coming from SubsetUpdateMessage.attribute
-            if attribute in ('style', 'type'):
+            # This will be None if triggered by SubsetCreateMessage
+            if attribute in ('style', 'type') or attribute is None:
                 # TODO: may need to add label and then rebuild the entire list if/when
                 # we add support for renaming subsets