Another you might like - New repo for RAP/ABAP
This repository contains code samples used in various blog posts. Each blog post has its own folder and contains respective source code files.
How to use Late Numbering in ABAP RAP Unmanaged implementation with Purchase Contract as an example.
SCN blog post - Late Numbering in Unmanaged RAP BO
How to use Early Numbering with Semantic Keys in ABAP RAP Managed implementation.
SCN blog Ppost - Early Numbering with Semantic Keys - RAP Managed Implementation