I seem to be having trouble modeling inherited classes using JoinedSubClassPart in Fluent NHibernate (release 524). I have seen other posts indicating that the approach I am using (see below) should work, yet at runtime I get the following exception (thrown by ImappingPart.PositionOnDocument method of JoinedSubClassPart):

XunitException: FluentNHibernate.Cfg.FluentConfigurationException : An invalid or incomplete configuration was used while creating a SessionFactory. Check PotentialReasons collection, and InnerException for more detail.

---- System.InvalidOperationException : Failed to compare two elements in the array. -------- System.NotSupportedException : Obsolete

Should this in fact work or has this been deprecated in favour of another approach?

I am hoping I am simply doing something wrong as I do like the idea of being able to add subclass mapping dynamically via AddPart().

Any help will be greatly appreciated!

---

A simplified version of my object model (which still fails) is as follows:

public class MyBaseClass
{
    public int Id { get; set; }
    public string CommonProperty { get; set; }
}

public class MySubClass1 : MyBaseClass
{
    public string MySubClass1Property { get; set; }
}

public class MySubClass2 : MyBaseClass
{
    public string MySubClass2Property { get; set; } 
}

And my mappings are as follows:

public class MyBaseClassMap : ClassMap<MyBaseClass>
{
    public MyBaseClassMap()
    {
        Not.LazyLoad();
        Id(x => x.Id).GeneratedBy.Identity();

        Map(x => x.CommonProperty);
        AddPart(new MySubClass1Map());
        AddPart(new MySubClass2Map());
    }
}

public class MySubClass1Map : JoinedSubClassPart<MySubClass1>
{
    public MySubClass1Map()
        : base("MyBaseClassId")
    {
        Not.LazyLoad();
        Map(x => x.MySubClass1Property);
    }
}

public class MySubClass2Map : JoinedSubClassPart<MySubClass2>
{
    public MySubClass2Map()
        : base("MyBaseClassId")
    {
        Not.LazyLoad();
        Map(x => x.MySubClass2Property);
    }
}

• nhibernate
• fluent-nhibernate
• nhibernate-mapping

After digging a little deeper, I found this fluent-nhibernate issue which explains that, as of r526 AddPart has been deprecated in favour of JoinedSubClass. After modifying my code to that shown below, I was able to get the modeling I was looking for.

In my base class map, I replaced the calls to AddPart with:

JoinedSubClass("MyBaseClassId", MySubClass1Map.AsJoinedSubClass());
JoinedSubClass("MyBaseClassId", MySubClass2Map.AsJoinedSubClass());

And my subclass maps changed to:

public class MySubClass1Map
{
    public static Action<JoinedSubClassPart<MySubClass1>> AsJoinedSubClass()
    {
        return sub =>
        {
             sub.Map(x => x.MySubClass1Property);
        };
    }
}

public class MySubClass2Map
{
    public static Action<JoinedSubClassPart<MySubClass2>> AsJoinedSubClass()
    {
        return sub =>
        {
             sub.Map(x => x.MySubClass2Property);
        };
    }
}