Problem with the order of fields in derived classes.

I have following inheritance structure of business objects:

1. public abstract class BusinessObject<T> : BusinessBase<T> where T : BusinessObject<T>
2. public abstract class AuthorizedUser : BusinessObject<AuthorizedUser>

+ Code
+ Email
+ Kind
+ Login
+ Name
+ Password
+ Phone
+ PreferredContact (enum ContactMethods { Email, Phone })

All properties is managed (using RegisterProperty, GetProperty, SetProperty).

3. public class AdminUser : AuthorizedUser
4. public class ClinicUser : AuthorizedUser

+ City
+ Comment
+ ConvenientTime
+ Fax
+ PracticeName
+ PracticeWebsite
+ State
+ Zip

All properties is managed.

With fresh database, I create admin user. I have AdminUser's field list as:

Field index : Field name
-------------------------
0 : Code
1 : Email
2 : Kind
3 : Login
4 : Name
5 : Password
6 : Phone
7 : PreferredContact

Then I load user list, create clinic user. I have ClinicUser's field list as:

Field index : Field name
-------------------------
0 : City
0 : Code
1 : Comment
2 : ConvenientTime
1 : Email
2 : Fax
2 : Kind
3 : Login
4 : Name
5 : Password
6 : Phone
7 : PracticeName
8 : PracticeWebsite
7 : PreferredContact
8 : State
9 : Zip

I got an exception from validation rule for [PracticeName]:
System.InvalidCastException: Unable to cast object of type 'ContactMethods' to type 'System.String'.

I temporarily fix that by:
+ Add inheritance level to field friendly name
+ Call SyncFieldIndex procedure before every action of create, insert.

        protected virtual void SyncFieldIndex()
        {
            List<Csla.Core.IPropertyInfo> list = FieldManager.GetRegisteredProperties();
            list.Sort(ComparePropertyInfo);
            for (int idx = 0; idx < list.Count; idx++)
            {
                list[idx].Index = idx;
            }
        }

        private int ComparePropertyInfo(Csla.Core.IPropertyInfo x, Csla.Core.IPropertyInfo y)
        {
            int result = string.Compare(x.FriendlyName, y.FriendlyName);
            if (result != 0) return result;
            return string.Compare(x.Name, y.Name);
        }

I would like to confirm that this is a bug or my wrong use of framework. Which is best way to overcome this problem.

Thanks for your help.

Hi,

I hit this problem too.  It has to do with the multiple levels of inheritence.  Search this forum for _dummy or dummy to find the solution, or check out the C# 2008 Business Objects book, page 248, RegisterProperty and Inheritance.

ajj3085:

Hi,

I hit this problem too.  It has to do with the multiple levels of inheritence.  Search this forum for _dummy or dummy to find the solution, or check out the C# 2008 Business Objects book, page 248, RegisterProperty and Inheritance.

Thanks for your help. I have read _dummy related threads. I have tried _dummy trick but it did not help.

        #region Dummy Workaround

        private static int _dummy;

        protected BusinessObject()
        {
            _dummy = 0;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            base.OnDeserialized(context);
            _dummy = 0;
        }

        #endregion


        #region Dummy Workaround

        private static int _dummy;

        protected AuthorizedUser()
        {
            _dummy = 0;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            base.OnDeserialized(context);
            _dummy = 0;
        }

        #endregion


        #region Dummy Workaround

        private static int _dummy;

        protected AdminUser()
        {
            _dummy = 0;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            base.OnDeserialized(context);
            _dummy = 0;
        }

        #endregion


        #region Dummy Workaround

        private static int _dummy;

        protected ClinicUser()
        {
            _dummy = 0;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            base.OnDeserialized(context);
            _dummy = 0;
        }

        #endregion

I have read "C# 2008 Business Objects" book, page 248. I have tried both ways: adding static constructor and initializing dummy static field. But it still did not help.

        #region Dummy Workaround

        private static int _forceInit;

        static BusinessObject() { }

        protected BusinessObject()
            : base()
        {
            _forceInit = 1;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            _forceInit = 1;
        }

        #endregion


        #region Dummy Workaround

        private static int _forceInit;

        static AuthorizedUser() { }

        protected AuthorizedUser()
            : base()
        {
            _forceInit = 1;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            _forceInit = 1;
        }

        #endregion


        #region Dummy Workaround

        private static int _forceInit;

        static AdminUser() { }

        protected AdminUser()
            : base()
        {
            _forceInit = 1;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            _forceInit = 1;
        }

        #endregion


        #region Dummy Workaround

        private static int _forceInit;

        static ClinicUser() { }

        protected ClinicUser()
            : base()
        {
            _forceInit = 1;
        }

        protected override void OnDeserialized(System.Runtime.Serialization.StreamingContext context)
        {
            _forceInit = 1;
        }

        #endregion

Did you add the _dummy code in every single level of your inheritance chain? You have to do that.

Joe

 

Sorry for replying on an old post, but i just ran into this problem.

We removed the _dummy or _forceInit from our inheritance classes and indeed the order of the fields are wrong between the FieldManager and the PropertyInfo.Index

I thought it would had been "fixed" in a new version.

I guess i'm mistaken about it being "fixed"

It should be fixed in current versions - there's even a unit test that confirms the fix.

The fix was to use reflection to walk the inheritance hierarchy, accessing a static field in each class, thus triggering the static field initialization in each class.

The method is called ForceStaticFieldInit() in the FieldDataManager class. You could put a breakpoint in that method to make sure it is being hit on the first use of each type - on the client and on the server.

Oh, one other thing.

If you are using Silverlight the rules are a little different because private reflection isn't possible. So the fix is in CSLA .NET for Silverlight, but it can only work if your PropertyInfo<T> fields are public in scope, not private. If they aren't public, then the reflection code can't see the fields and thus can't trigger the field initialization.