show a nice error message if the program contains non-exportable blocks

1 files changed, 7 insertions, 2 deletions

diff --git a/turtleblocks.py b/turtleblocks.py
index d5dca1c..a42420b 100755
--- a/turtleblocks.py
+++ b/turtleblocks.py
@@ -52,6 +52,7 @@ from gettext import gettext as _
 
 from TurtleArt.taconstants import (OVERLAY_LAYER, DEFAULT_TURTLE_COLORS,
                                    TAB_LAYER, SUFFIX)
+from TurtleArt.taprimitive import PyExportError
 from TurtleArt.tautils import (data_from_string, get_save_name)
 from TurtleArt.tawindow import TurtleArtWindow
 from TurtleArt.taexportlogo import save_logo
@@ -532,8 +533,12 @@ Would you like to save before quitting?'))
 
     def _do_save_python_cb(self, widget):
         ''' Callback for saving the project as Python code. '''
-        # TODO implement
-        pythoncode = save_python(self.tw)
+        # catch PyExportError and display a user-friendly message instead
+        try:
+            pythoncode = save_python(self.tw)
+        except PyExportError as pyee:
+            self.tw.showlabel('status', str(pyee))
+            return
         if not pythoncode:
             return
         save_type = '.py'