Enrico, just to clarify: Peter’s solution is more “complicated” because it addresses another use case. Josteins solution shows you how to handle elements that return a single point coordinate as their location (e.g. furniture). Peter’s solution shows you how to handle line-based elements such as walls. Naturally it will be more “complicated” as it entails more data/work.
Regarding your question on learning material - have you gone through the language guide that is available in the “Learn” section on this site?