Fix obj.save() when threading is enabled (#5993)

panel/config.py

@@ -393,7 +393,11 @@ def __setattr__(self, attr, value):
  if not init or (attr.startswith('_') and attr.endswith('_')) or attr == '_validating':
  return super().__setattr__(attr, value)
  value = getattr(self, f'_{attr}_hook', lambda x: x)(value)
- if attr in _config._globals or self.param._TRIGGER:
+ if (
+ attr in _config._globals
+ or (attr.startswith("_") and attr[1:] in _config._globals)
+ or self.param._TRIGGER
+ ):
  super().__setattr__(attr if attr in self.param else f'_{attr}', value)
  elif state.curdoc is not None:
  if attr in _config._parameter_set:

panel/tests/test_server.py

@@ -927,3 +927,26 @@ def test_server_no_warning_empty_layout(port, caplog):
  finally:
  bk_logger.setLevel(old_level)
  bk_logger.propagate = old_propagate
+
+
+def test_server_threads_save(threads, port, tmp_path):
+ # https://github.com/holoviz/panel/issues/5957
+
+ button = Button()
+ fsave = tmp_path / 'button.html'
+
+ def cb(event):
+ button.save(fsave)
+
+ def simulate_click():
+ button._comm_event(state.curdoc, ButtonClick(model=None))
+
+ button.on_click(cb)
+
+ def app():
+ state.curdoc.add_next_tick_callback(simulate_click)
+ return button
+
+ serve_and_request(app)
+
+ wait_until(lambda: fsave.exists())