How do I override a convention's cascade rule in fluent nhibernate - fluent-nhibernate

Question

I have two classes
public class Document
{
public virtual int Id { get; set; }
public virtual IList<File> Files { get; set; }
}
public class File
{
public virtual int Id { get; protected set; }
public virtual Document Document { get; set; }
}
with the following convention:
public class HasManyConvention : IHasManyConvention
{
public bool Accept(IOneToManyPart target)
{
return true;
}
public void Apply(IOneToManyPart target)
{
target.Cascade.All();
}
}
and these mapping overrides
public class DocumentMappingOverride : IAutoMappingOverride<Document>
{
public void Override(AutoMap<Document> mapping)
{
mapping.HasMany(x => x.Files)
.Inverse()
// this line has no effect
.Cascade.AllDeleteOrphan();
}
}
public class FileMappingOverride : IAutoMappingOverride<File>
{
public void Override(AutoMap<File> mapping)
{
mapping.References(x => x.Document).Not.Nullable();
}
}
I understand that I need to make an IClassConvention for Document to
change the cascade behaviour, however I can't get this to work!
If i do this:
public class DocumentConvention : IClassConvention
{
public bool Accept(IClassMap target)
{
return target.EntityType == typeof(Document);
}
public void Apply(IClassMap target)
{
target.SetAttribute("cascade", "all-delete-orphan");
}
}
I get: "The 'cascade' attribute is not declared."
If i do this:
public class DocumentConvention : IClassConvention
{
public bool Accept(IClassMap target)
{
return target.EntityType == typeof(Document);
}
public void Apply(IClassMap target)
{
target.HasMany<Document, File>(x => x.Files)
.Inverse()
.Cascade.AllDeleteOrphan();
}
}
Then I get:
"Duplicate collection role mapping Document.Files"
so i added:
mapping.IgnoreProperty(x => x.Files);
to my document mapping, but then Files is always empty.
What am I doing wrong?
How can I override the cascade rule for a single HasMany relationship?
Thanks
Andrew
P.s. Sorry for the cross post with this but I need to get this solved asap.

Answer 1

I know this was forever ago (in computer time) and you might have already solved this. In case you haven't or someone else with a similar question sees this, here goes:
I think you need to create a class that implements IHasManyConvention. IClassConvention modifies an IClassMap (the <class> element) target. cascade is not a valid attribute for <class> so that accounts for the first error. On your second attempt, you were re-mapping the collection, resulting in the "duplicate collection" error.
IHasManyConvention targets an IOneToManyPart, upon which you should be able to call Cascade.AllDeleteOrphan() or just SetAttribute("cascade", "all-delete-orphan") if the former didn't work for some reason.
EDIT
Sorry, I missed that you already had a IHasManyConvention. Since you want to override your convention for just one type, you should just change the Accept method on your convention for that type. Instead of return true;, pull in what you had on your DocumentConvention:
return target.EntityType == typeof(Document);
I believe that OneToManyPart.EntityType references the containing entity type (i.e. Document).