You should get CompanyId from claims, instead of storing it in a property on a singleton. Why did you comment that out?
See AppVersionHelper.cs if you didn't replace it.
Better to check https://aspnetzero.com/Download.
Do you mean MVC 5, which uses EF 6?
https://aspnetboilerplate.com/Pages/Documents/Data-Filters#entity-framework
Duplicate of #6285
Show code.
Are you trying to ask "How to throw an exception for DeleteBehavior.Restrict (Cascade Delete) on soft delete"?
There is no standard solution. If you want to implement a general solution, you can look at an attempt at DeleteBehavior.Cascade on soft delete (aspnetboilerplate/aspnetboilerplate#3559) for inspiration. I think Restrict does not have the same blocking issues, since you only need to visit one level unlike cascade delete, but it may still be non-trivial.
No, it is not possible. See discussion in aspnetzero/aspnet-zero-core#1033.
That shows how to store a value in claims. The value is used in GetCurrentUsersOuIdOrNull.
It is not required for data filters to work if you get the value from elsewhere (e.g. DB).
What's the joke?
