Question

I have a DAL to CRUD product data.

For example:

Order someOrder = new Order();
someOrder.Description = "Test";

someOrder.Save();
someOrder.Remove();

I need to design the DAL so that only users who have a lock on an Order type object can carry out CRUD operations.

My idea is to pass the session to the CRUD methods. Once I pass the session, the method will check whether that user has a lock on that specific object, and if yes, it will carry proceed with executing that method.

For example:

someOrder.Save(sessionThatContainsLockInformation);

// Pseudo-code
public void Save(Session session)
{

   1. Get user GUID from the session.
   2. Get lock details from the session.
   3. Check that the provided user has a lock.
   4. On success, proceed with saving the order.

}

I’m concerned with the fact that I’m using Sessions in the data access layer. My intuition tells me that I shouldn’t be doing this. My goal is to write as little code as possible to promote the re-usability of code, but I seem to be stuck with the same ideas.

Can somebody please advise me on whether this is a sensible approach, or whether it has some fundamental disadvantages or maintenance overheads?

Any alternative solutions are welcome. I’m not interested in the code, just some ideas please.

Thank you

Answer 1

Ok, thanks for your clarification, I think I understand your concerns now more clearly.

I faced a similar issue some time ago. My solution was a common superclass (in your classes it would be a superclass for Order, Item, Customer) with all parameters that are the same (timestamp changed, who did the change etc). I then created a utility class where all the checks you mention were taken care of.
So this “maintenance” logic is implemented in one place only.

I am not saying this is the best way to do it, it’s just something that worked for me…

Hope this helps,
Jan