Prevent from switching to link column type

Author: basteks

seatable_api/api_gateway.py

@@ -675,6 +675,8 @@ def modify_column_type(self, table_name, column_key, new_column_type):
         """
         if new_column_type not in ColumnTypes:
             raise ValueError("type %s invalid!" % (new_column_type,))
+        if new_column_type == ColumnTypes.LINK:
+            raise ValueError("Switching to link column type is not allowed!")
         url = self._column_server_url()
         json_data = {
             'op_type': MODIFY_COLUMN_TYPE,

seatable_api/main.py

@@ -914,6 +914,8 @@ def modify_column_type(self, table_name, column_key, new_column_type):
         """
         if new_column_type not in ColumnTypes:
             raise ValueError("type %s invalid!" % (new_column_type,))
+        if new_column_type == ColumnTypes.LINK:
+            raise ValueError("Switching to link column type is not allowed!")
         url = self._column_server_url()
         json_data = {
             'op_type': MODIFY_COLUMN_TYPE,