sonata-project/SonataAdminBundle — pull request #2323 by andrey-borue (2014-08-20 05:40:52+00:00)
Title: Supporting mapping by uid

If use the uid (/admin/categories/ec6b7cd1-2281-4b82-aaf0-5126e317933f/categories_json/list), instead of id (/admin/categories/56/categories_json/list), then the expression does not work.