Merge pull request spacetelescope#384 from rosteen/no-data-error

Fix nonexistent file load

jdaviz/app.py

@@ -272,7 +272,11 @@ def load_data(self, file_obj, parser_reference=None, **kwargs):
             # Properly form path and check if a valid file
             file_obj = pathlib.Path(file_obj)
             if not file_obj.exists():
-                raise FileNotFoundError("Could not locate file: " + file_obj)
+                msg_text = "Error: File {} does not exist".format(file_obj)
+                snackbar_message = SnackbarMessage(msg_text, sender=self,
+                                                   color='error')
+                self.hub.broadcast(snackbar_message)
+                raise FileNotFoundError("Could not locate file: {}".format(file_obj))
             else:
                 # Convert path to properly formatted string (Parsers do not accept path objs)
                 file_obj = str(file_obj)