Cascade Saves with Fluent NHibernate AutoMapping - fluent-nhibernate

Question

How do I "turn on" cascading saves using AutoMap Persistence Model with Fluent NHibernate?
As in:
I Save the Person and the Arm should also be saved. Currently I get
"object references an unsaved transient instance - save the transient instance before flushing"
public class Person : DomainEntity
{
public virtual Arm LeftArm { get; set; }
}
public class Arm : DomainEntity
{
public virtual int Size { get; set; }
}
I found an article on this topic, but it seems to be outdated.

Answer 1

This works with the new configuration bits. For more information, see http://fluentnhibernate.wikia.com/wiki/Converting_to_new_style_conventions
//hanging off of AutoPersistenceModel
.ConventionDiscovery.AddFromAssemblyOf<CascadeAll>()
public class CascadeAll : IHasOneConvention, IHasManyConvention, IReferenceConvention
{
public bool Accept( IOneToOnePart target )
{
return true;
}
public void Apply( IOneToOnePart target )
{
target.Cascade.All();
}
public bool Accept( IOneToManyPart target )
{
return true;
}
public void Apply( IOneToManyPart target )
{
target.Cascade.All();
}
public bool Accept( IManyToOnePart target )
{
return true;
}
public void Apply( IManyToOnePart target )
{
target.Cascade.All();
}
}

Answer 2

Updated for use with the the current version:
public class CascadeAll : IHasOneConvention, IHasManyConvention, IReferenceConvention
{
public void Apply(IOneToOneInstance instance)
{
instance.Cascade.All();
}
public void Apply(IOneToManyCollectionInstance instance)
{
instance.Cascade.All();
}
public void Apply(IManyToOneInstance instance)
{
instance.Cascade.All();
}
}

Answer 3

The easiest way I've found to do this for a whole project is to use DefaultCascade:
.Conventions.Add( DefaultCascade.All() );
Go to "The Simplest Conventions" section on the wiki, for this, and a list of others.
Here's the list from the Wiki:
Table.Is(x => x.EntityType.Name + "Table")
PrimaryKey.Name.Is(x => "ID")
AutoImport.Never()
DefaultAccess.Field()
DefaultCascade.All()
DefaultLazy.Always()
DynamicInsert.AlwaysTrue()
DynamicUpdate.AlwaysTrue()
OptimisticLock.Is(x => x.Dirty())
Cache.Is(x => x.AsReadOnly())
ForeignKey.EndsWith("ID")
A word of warning - some of the method names in the Wiki may be wrong. I edited the Wiki with what I could verify (i.e. DefaultCascade and DefaultLazy), but can't vouch for the rest. But you should be able to figure out the proper names with Intellisense if the need arises.

Answer 4

The Convention Method Signatures have changed. For the new answer that does exactly what this question asks see THIS QUESTION.

Answer 5

You can also make cascading the default convention for all types. For example (using the article you linked to as a starting point):
autoMappings.WithConvention(c =>
{
// our conventions
c.OneToOneConvention = o => o.Cascade.All();
c.OneToManyConvention = o => o.Cascade.All();
c.ManyToOneConvention = o => o.Cascade.All();
});