When you define a RESTService from a viewJsonService, we cannot get document-level data directly. Instead, there is a mid-level class RestViewNavigatorFactory provides column-level access and system columns like UniversalID or read status etc.
It makes sense to have access to more information about the entry just like simple functions in traditional view columns:
- Attachment names and/or lengths,
- Creation and Last Modification Dates
- Size of the document