BusinessListBase<T>.Remove doesn't work

Question

I'm new on CSLA.Net and I've some difficult to remove a child object from a list.

I've 3 classes :

• Scenario : BusinessBase<Scenario>
• ScenarioPermissions : BusinessListBase<ScenarioPermissions, ScenarioPermission>
• ScenarioPermission : BusinessBase<ScenarioPermission>

Class Scenario contains one field of type ScenarioPermissions.

When I Try to do Scenario.Permissions.Add(obj) and Scenario.Save(), it works correctly.

But if I want to do Scenario.Permissions.Remove(obj) and Scenario.Save(), it continues without deleting my ScenarioPermission object from the database.

public class Scenario : BusinessBase<Scenario>, IMakeCopy
{
    private static readonly PropertyInfo<ScenarioPermissions> m_PermissionsProperty = RegisterProperty<ScenarioPermissions>(c => c.m_Permissions);

    public ScenarioPermissions m_Permissions
    {
        get
        {
            if (!FieldManager.FieldExists(m_PermissionsProperty))
            {
                SetProperty(m_PermissionsProperty, ScenarioPermissions.NewPermissions());
            }
            return GetProperty(m_PermissionsProperty);
        }
    }

    public ReadOnlyCollection<Model.Users.User> Permissions
    {
        get
        {
            var collection = new List<Model.Users.User>();
            foreach (var item in m_Permissions)
            {
                collection.Add(Model.Users.User.GetUser(item.UserID));
            }

            //Adds administrators users...
            var admins = Users.Users.GetUsers(true).Where(u => u.Role.InvariantName == "SystemAdministrator" || u.Role.InvariantName == "SuperAdministrator");
            foreach (var item in admins)
            {
                collection.Add(item);
            }
            return new ReadOnlyCollection<Model.Users.User>(collection.OrderBy(u => u.FullName).ToArray());
        }
    }

    public void AddPermission(Model.Users.User user)
    {
        if (user == null)
        {
            throw new ArgumentNullException("user");
        }

        ScenarioPermission permission = ScenarioPermission.NewPermission(this, user);
        if (!this.m_Permissions.Contains(permission))
        {
            this.m_Permissions.Add(permission);
        }
    }

    public void RemovePermission(Model.Users.User user)
    {
        if (user == null)
        {
            throw new ArgumentNullException("user");
        }

        ScenarioPermission permission = this.m_Permissions.FirstOrDefault(p => p.UserID == user.Id);
        if (permission != null)
        {
            this.m_Permissions.Remove(permission);
        }
    }

    protected override void DataPortal_Update()
    {
        using (var ctx = DbContextManager<DatabaseContext>.GetManager())
        {
            var context = ctx.DbContext;

            var scenarioId = ReadProperty(m_IdProperty);
            var scenario = context.Scenarios.FirstOrDefault(s => s.Id == scenarioId);
            if (scenario != null)
            {
                scenario.Name = ReadProperty(m_NameProperty);
                //Some codes....
                context.SaveChanges();
            }
            FieldManager.UpdateChildren(this);
        }
    }

    protected override void DataPortal_DeleteSelf()
    {
        DataPortal_Delete(ReadProperty(m_IdProperty));
    }

    private void DataPortal_Delete(Guid id)
    {
        using (var contextManager = DbContextManager<DatabaseContext>.GetManager())
        {
            var context = contextManager.DbContext;
            var scenario = context.Scenarios.FirstOrDefault(s => s.Id == id);
            if (scenario != null)
            {
                context.Scenarios.Remove(scenario);
                context.SaveChanges();
            }
        }

        Dispatcher.CurrentDispatcher.Invoke(new Action(() => ScenarioList.Delete(id)));
    }
}



    public class ScenarioPermissions : BusinessListBase<ScenarioPermissions, ScenarioPermission>
    {
        public static ScenarioPermissions NewPermissions()
        {
            return DataPortal.Create<ScenarioPermissions>();
        }

        public static ScenarioPermissions GetUsersByScenario(Scenario scenario)
        {
            return DataPortal.FetchChild<ScenarioPermissions>(scenario);
        }

        private void Child_Fetch(Scenario obj)
        {
            using (var ctx = DbContextManager<DatabaseContext>.GetManager())
            {
                var context = ctx.DbContext;
                var scenario = context.Scenarios.Where(s => s.Id == obj.Id).FirstOrDefault();
                if (scenario != null)
                {
                    foreach (var item in scenario.Users)
                    {
                        this.Add(ScenarioPermission.NewPermission(scenario.Id, item.Id));
                    }
                }
            }
        }
    }


    public class ScenarioPermission : BusinessBase<ScenarioPermission>
    {

        private static readonly PropertyInfo<Guid> m_ScenarioID = RegisterProperty<Guid>(p => p.ScenarioID);

        public Guid ScenarioID
        {
            get { return GetProperty(m_ScenarioID); }
            private set { SetProperty(m_ScenarioID, value); }
        }

        private static readonly PropertyInfo<int> m_UserID = RegisterProperty<int>(p => p.UserID);

        public int UserID
        {
            get { return GetProperty(m_UserID); }
            private set { SetProperty(m_UserID, value); }
        }

        public static ScenarioPermission NewPermission(Scenario scenario, Model.Users.User user)
        {
            return NewPermission(scenario.Id, user.Id);            
        }

        public static ScenarioPermission NewPermission(Guid scenarioID, int userID)
        {
            var newObj = DataPortal.CreateChild<ScenarioPermission>();
            newObj.ScenarioID = scenarioID;
            newObj.UserID = userID;
            return newObj;
        }

        private ScenarioPermission() { /* Used for Factory Methods */}


        private void Child_Insert(Scenario scenario)
        {
            DataPortal_Insert();
        }

        private void Child_DeleteSelf(Scenario scenario)
        {
            DataPortal_DeleteSelf();
        }

        private void Child_DeleteSelf()
        {
            DataPortal_DeleteSelf();
        }

        protected override void DataPortal_Insert()
        {
            using (var ctx = DbContextManager<DatabaseContext>.GetManager())
            {
                var context = ctx.DbContext;
                var scenario = context.Scenarios.FirstOrDefault(s => s.Id == ScenarioID);
                var user = context.Users.FirstOrDefault(u => u.Id == UserID);

                if (scenario != null && user != null)
                {
                    scenario.Users.Add(user);
                    context.SaveChanges();
                }
            }
        }

        protected override void DataPortal_DeleteSelf()
        {
            using (var ctx = DbContextManager<DatabaseContext>.GetManager())
            {
                var context = ctx.DbContext;
                var scenario = context.Scenarios.FirstOrDefault(s => s.Id == ScenarioID);
                var user = context.Users.FirstOrDefault(u => u.Id == UserID);

                if (scenario != null && user != null)
                {
                    if (scenario.Users.Contains(user))
                    {
                        scenario.Users.Remove(user);
                        context.SaveChanges();
                    }
                }
            }
        }

        public override bool Equals(object obj)
        {
            // If parameter is null return false.
            if (obj == null)
            {
                return false;
            }

            // If parameter cannot be cast to ScenarioPermission return false.
            ScenarioPermission p = obj as ScenarioPermission;
            if ((System.Object)p == null)
            {
                return false;
            }

            // Return true if the fields match:
            return (this.ScenarioID == p.ScenarioID) && (this.UserID == p.UserID);

        }
    }

Answer 1

I've just find the solution : When I fetched the children of ScenariosPermissions, I created children instead of fetching existing... So, when I wanted to remove permissions, the existing objects was considered by CSLA as a NewObject, so it does not the Delete() ;-)

Correction :

public class ScenarioPermissions : BusinessListBase<ScenarioPermissions, ScenarioPermission>
{
    public static ScenarioPermissions NewPermissions()
    {
        return DataPortal.Create<ScenarioPermissions>();
    }

    public static ScenarioPermissions GetUsersByScenario(Scenario scenario)
    {
        return DataPortal.FetchChild<ScenarioPermissions>(scenario);
    }

    private void Child_Fetch(Scenario obj)
    {
        RaiseListChangedEvents = false;

        using (var ctx = DbContextManager<DatabaseContext>.GetManager())
        {
            var context = ctx.DbContext;
            var scenario = context.Scenarios.Where(s => s.Id == obj.Id).FirstOrDefault();
            if (scenario != null)
            {
                foreach (var item in scenario.Users)
                {
                    this.Add(ScenarioPermission.GetPermission(scenario.Id, item.Id));
                }
            }
        }
        RaiseListChangedEvents = true;
    }
}
public class ScenarioPermission : BusinessBase<ScenarioPermission>
{
    public static ScenarioPermission GetPermission(Guid scenarioID, int userID)
    {
       return DataPortal.FetchChild<ScenarioPermission>(scenarioID, userID);
    }
    private void Child_Fetch(Guid scenarioID, int userID)
    {
        LoadProperty(m_ScenarioID, scenarioID);
        LoadProperty(m_UserID, userID);
    }
}