The right way to do inheritance in CSLA BO should be always adding generic in base/ancester’s class declaration.
e.g., instead of
class Car :BusinessBase {}
we should
class Car<T> :BusinessBase where T: BusinessBase<T> {}
Note: You will encounter the famous “dummy” staic field problem of CSLA.
The benefits of this includes,
- Don’t have to override base.Save().
- The registered property in base will get the correct type of inheritor.
- Child properties will always be aware the correct inheritor’s type T. (Maybe they shouldn’t)
But, this will cause the child_insert() much harder to write if you have child properties in base Car BO. This is invalid:
private void Child_Insert(Car<> parent) {…}
And this doesn’t work either:
private void Child_Insert(object parent) {
// Only check one level inheritance, to do recursive check, see details in this post.if (!(parent.GetType().BaseType.GetGenericTypeDefinition()== typeof(Car<>)))
throw new NotSupportedException(“….”);// Set parent id , this line won’t compile.
LoadProperty<int>(CarIdProperty, ((Car<>)parent).CarId);}
I can add generic to those child BO, but that looks too ugly, like Tire<T>, Seat<T>, they should be general, same to all the Cars.
Another solution is, creating an ICar interface.
private void Child_Insert(ICar parent) {…}
It looks strange, but actually this can make child BO code much eaisier to write.
