def app_url_defaults(self, f: T_url_defaults) -> T_url_defaults:
        """Like :meth:`url_defaults`, but for every request, not only those handled by
        the blueprint. Equivalent to :meth:`.Flask.url_defaults`.
        """
        self.record_once(
            lambda s: s.app.url_default_functions.setdefault(None, []).append(f)
        )
        return f
Like :meth:`url_defaults`, but for every request, not only those handled by
        the blueprint. Equivalent to :meth:`.Flask.url_defaults`.
        
src/flask/sansio/blueprints.py