How to use VirtualProperty to obtain line numbers？

[suxuanning]

1、How to use VirtualProperty to obtain line numbers？
2、How should VirtualProperty be used? Can you give a simple example?

[rfoltyns]

You can find a few interesting examples here: https://github.com/rfoltyns/log4j2-elasticsearch-examples.

event:* is not possible at the moment due to one of the limitations of VirtualProperty feature - no access to event during serialisation. Fortunately, it's fairly straightforward to implement and I will happily accepts PRs in this scope