Coa Entry Form: Add user name and date when a new description act is created OR edited

When a new description act is created, it should also be linked to the user that is currently logged in, as well as to the date when it was created. The linkage to the user should be done with dcterms:creator. The current user can be queried with this:

SELECT ?__useruri__ ?userName { BIND(REPLACE(SUBSTR(STR(?__useruri__), 41), "%40", "@") as ?userName) }

The variable ?__useruri__ should contain the uri of the user that is currently logged in.