Create content with fixed UUID (in AddView)

Is it possible to set the UUID in an AddForm?

My customer wants to mark some text in (document 1) TinyMce, click 'add content' and after the content (document2) is created the link 'works'.

I can construct the UUID in javascript (can check if it exists already in the AddCiew, there will not be too many documents, so the chances of duplicates will be slim)

Or do I need to change the UUID after creation (in subscribers) ??

UPDATE: I did not find a way to do this properly, so I added a hidden field for the content type and used a subscriber to change the UUID 'just after creation'.

(completely off topic, but for some reason the field placeholder did not show in edit view, maybe there is some code somewhere that hides 'placeholders' ?)

def change_uuid(object, event):
    if object.portal_type in  ['aaa', 'bbb' ]:
        if hasattr(object, 'placeholder'):
        # if object.placeholder is not None:
            lenght = len( object.placeholder ) 
            #I thought UUID were 36, but seems to be 32 in plone (?)
            if  lenght == 32:
                setattr(object, '_plone.uuid', object.placeholder) 
                setattr(object, 'placeholder', '')