To simplify things and help our users to be more productive, we have archived the current forum and focus our efforts on helping developers on Stack Overflow. You can post new questions on Stack Overflow or join our Discord channel.
The books JPAContainer part is still mostly based on documentation for version 1.x. Marko is currently working on a major overhaul for that part. The tutorial should be mostly up to date, but it just discusses using std Vaadin filters.