As mentioned earlier, starting with N4 v. 2.0, N4 supports code extensions that are inherited in the application layer from the underlying Framework layer. Although this document describes the extensibility features that do and do not use the Framework support, we recommend that for any future development you use the Framework Code Extensions as we plan to deprecate the code extensions that do not use Framework support.
Some general guidelines for using Framework Code Extensions:
To implement additional validations for an entity's persisted fields, use the Entity Life Cycle Interceptors (LCI).
To deploy your shared code, use the Library Code Extensions instead of the Groovy Plug-ins.