In order to create a post processor to the SlingPostServlet (will be systematically called after POST is processed in transient space, before save is done):
- create a service implementing org.apache.sling.servlets.post.SlingPostProcessor
- implement the post processing in process(SlingHttpServletRequest request, List<Modification> changes)
Note that :
- service.ranking property can be specified to order the post processor among the others
- every change done to the repository should be added to List changes