Slight tweak to get_text

common/lib/xmodule/xmodule/x_module.py

@@ -778,6 +778,13 @@ class XModuleDescriptor(XModuleMixin, HTMLSnippet, ResourceTemplates, XBlock):
                 json_choice = field.to_json(json_choice)
             return json_choice
 
+        def get_text(value):
+            """Localize a text value that might be None."""
+            if value is None:
+                return None
+            else:
+                return self.runtime.service(self, "i18n").ugettext(value)
+
         metadata_fields = {}
 
         # Only use the fields from this class, not mixins
@@ -788,9 +795,6 @@ class XModuleDescriptor(XModuleMixin, HTMLSnippet, ResourceTemplates, XBlock):
             if field.scope != Scope.settings or field in self.non_editable_metadata_fields:
                 continue
 
-            def get_text(value):
-                return self.runtime.service(self, "i18n").ugettext(value) if value is not None else None
-
             # gets the 'default_value' and 'explicitly_set' attrs
             metadata_fields[field.name] = self.runtime.get_field_provenance(self, field)
             metadata_fields[field.name]['field_name'] = field.name