Current user as default for 'schema.Choice' ( Plone 6 Classic / xml )

1

Is it possitble to set 'default user' in XML for a choice field?
I want the default value to be 'current user'

<field name="select_user" type="zope.schema.Choice">
  <vocabulary>plone.app.vocabularies.Users</vocabulary>
</field>
2

What happens when you insert a <defaultFactory>mypackage.myFunction</defaultFactory> element
with the dotted name of your custom value provider as the parameter?

See Dexterity XML — Plone Documentation v4.3 - this should still work...

3

Should probably work (but I need to figure out 'what is expected for default ' (user id or something else).

That said: I assume there must be something avalable already (isnt this used 'many other places' ?

UPDATE:
Something like this should work (I think using something else than plone.api is faster, and the check for 'Authenticated' feels a bit strage (done to avoid errors with zope users). Probably dont need to be 'ContextAware' either.

<defaultFactory>my.addon.current_user.getUserId</defaultFactory> 

from zope.interface import provider
from zope.schema.interfaces import IContextAwareDefaultFactory
from plone import api

#@provider(IDefaultFactory)

@provider(IContextAwareDefaultFactory)
def getUserId(context):
    current_user = api.user.get_current()
    user_groups =  current_user.getGroups()
    if 'AuthenticatedUsers' in user_groups:
        return current_user.id
    return None