Question

I have a use case that I’ve never really dealt with before. I have an object that after the user clicks “Save” should not be changed. Initially I created two objects, DraftObject and SavedObject. For the latter I created a constructor that only accepted the DraftObject and set each property as protected set.

This works but does not seem ideal. It seems like I should be able to set a property on my object that controls whether the other fields are editable. What’s the best way to do this? Forgive my pseudo-code, but this is what I was toying with:

public class MySpecialObject {
        public virtual string MyProperty { get { return MyProperty; } 
            set {
                if (State == "Locked")
                {
                    return;
                } else
                {
                    MyProperty = MyProperty;
                }
            }
         public virtual string State { get { return State; }
            set {
                 if (State == "Locked")
                 {
                     return;
                 } else
                 { 
                   State = State;
                 }
            }

This seems ugly, especially if I have to do this to every single property in my class. There’s got to be a better way to do this, any ideas?

Answer 1

This is actually a fairly interesting issue, because there’s a lot to be said for objects that are either immutable, or that start off mutable but can be locked down to become immutable.

Addressing your question in specific, I think it may make more sense to throw an InvalidOperationException if there’s an attempt to set a locked property. I don’t know of any cleaner or better way.

edit

In a parallel post, JLWarlow pointed out that this is exactly how SecureString works when you call MakeReadOnly.