Document Title not using translated values

If the document type uses a field for the Title, say for example, it uses {purpose} in the Stock Entry, how do I display the translated value of the pre-defined items in the list? I think the system should smart enough to display the translated value if applicable. Can any one show me what is the Title render logic?

Regards,
Jian

For the time being, I probably have to use code behind to generate the autoname to display the localized values.
def autoname(self):

Regards,
Jian

I have raised the issue in github. #15052

Regards,
Jian