How to map composite-id with fluent nhibernate using an interface?

Question

I'm trying to switch out .hbm mappings to fluent mappings and have a problem with the mapping of composite-ids and the usage of Interfaces

the Class looks as follows:

public class ClassWithCompositeId {
  public virtual IKeyOne KeyOne { get; set; }
  public virtual IKeyTwo KeyTwo { get; set; }
}

our hbm mapping looks like this:

<hibernate-mapping ...>
   <class name="ClassWithCompositeId" table="t_classwithcompositeid">
      <composite-id>      
         <key-many-to-one name="KeyOne" column="colkeyone" class="company.namespace.boSkillBase, BL_Stammdaten" />
         <key-many-to-one name="KeyTwo" column="colkeytwo" class="boQualifikation" />         
      </composite-id>
</hibernate-mapping>

Please note, that we got interfaces in the Class! No I'm trying to map this with Fluent nhibernate.

Map {
   public ClassWithCompositeIdMap() {
         CompositeId()
            .KeyReference(x => x.KeyOne, "colkeyone")
            .KeyReference(x => x.KeyTwo, "colkeytwo");
          ...
   }
}

But now Fluent generates the Mapping as follows:

...
 <composite-id mapped="false" unsaved-value="undefined">
      <key-many-to-one name="KeyOne" class="company.namespace.IKeyOne, Interfaces, Version=0.1.4.3379, Culture=neutral, PublicKeyToken=null">
        <column name="colkeyone" />
      </key-many-to-one>
      <key-many-to-one name="KeyTwo" class="company.namespace.IKeyTwo, Interfaces, Version=0.1.4.3379, Culture=neutral, PublicKeyToken=null">
        <column name="colkeytwo" />
      </key-many-to-one>
    </composite-id>
...

The "Class" Attribute points now to the Interface not to the implementation of this interface which results in an error.

How can I tell Fluent nHibernate to use another class as the attribute value?

Answer 1

Tanks! But I've found the answer on my on. In fact i found a missing feature in fluent nHibernate. The feature has already been added to the dev branch by Paul Batum.

You would use it like so:

   Map {
      public ClassWithCompositeIdMap() {
            CompositeId()
               .KeyReference(x => x.KeyOne, k =>
                   k.Type<KeyOneImplementation>(), "colkeyone")
               .KeyReference(x => x.KeyTwo, k =>
                   k.Type<KeyTwoImplementation>(), "colkeytwo");
             ...
      }
   }

http://github.com/paulbatum/fluent-nhibernate/tree/dev

You can see the original Conversation here: http://support.fluentnhibernate.org/discussions/help/349-how-to-map-a-composite-id-when-using-interfaces-or-how-to-change-the-class-attribute-in-the-key-many-to-one-tag