Fallback to fieldname if alias is empty

Author: manisandro

src/config_generator/qgs_reader.py

@@ -341,7 +341,7 @@ def __layer_edit_metadata(self, root, layer_metadata, maplayer, layername, map_p
             field = {}
 
             # Alias
-            field['alias'] = alias.get('name')
+            field['alias'] = alias.get('name') or fieldname
 
             # Default value
             field['defaultValue'] = element_attr(
@@ -366,8 +366,10 @@ def __layer_edit_metadata(self, root, layer_metadata, maplayer, layername, map_p
                 self.__column_metadata(
                     field, jointables[field['joinfield']['table']], field['joinfield']['field']
                 )
-            elif not field['expression']:
-                # NOTE: Don't query column metadata for virtual fields
+            elif field['expression']:
+                field['data_type'] = element_attr(
+                    maplayer.find("expressionfields/field[@name='%s']" % fieldname), 'typeName')
+            else:
                 self.__column_metadata(
                     field, layer_metadata, fieldname
                 )