Fix bug when closing a dataset (#653)

* Fix bug when closing a dataset

* Add changelog entry

Author: cbrnr

CHANGELOG.md

@@ -1,4 +1,6 @@
 ## [UNRELEASED] · YYYY-MM-DD
+### 🔧 Fixed
+- Fix a bug where a dataset could not be closed in the sidebar ([#653](https://github.com/cbrnr/mnelab/pull/653) by [Clemens Brunner](https://github.com/cbrnr))
 
 ## [1.5.0] · 2026-05-21
 ### ✨ Added

src/mnelab/model.py

@@ -523,6 +523,8 @@ def get_info(self):
         info : dict
             Dictionary with information on current data set.
         """
+        if self.current["data"] is None:
+            self.reload_dataset(self.index)
         data = self.current["data"]
         fname = self.current["fname"]
         ftype = self.current["ftype"]

src/mnelab/widgets/sidebar.py

@@ -290,7 +290,7 @@ def showCloseButton(self, hovered_item):
 
     def _close_dataset(self, dataset_id):
         """Close a dataset, cascading to descendants with a confirmation dialog."""
-        descendants = self.parent.model.find_descendants(dataset_id)
+        descendants = self.parent.window().model.find_descendants(dataset_id)
         if descendants:
             n = len(descendants)
             msg = QMessageBox(self)
@@ -306,7 +306,7 @@ def _close_dataset(self, dataset_id):
             msg.setDefaultButton(QMessageBox.StandardButton.Cancel)
             if msg.exec() != QMessageBox.StandardButton.Ok:
                 return
-        self.parent.model.remove_data_cascade(dataset_id)
+        self.parent.window().model.remove_data_cascade(dataset_id)
 
 
 class SidebarWidget(QWidget):