Hi

I wish to detect when my many-to-many relationship is being persisted. I am using a bag for this.

NHibernate does not call into my Interceptor to tell me when these bags are being saved (it calls in for Pre, Post flush and FindDirty)

Any help would be much appreciated,
Mark.

Looking at the source there doesn't seem to be any support for intercepting persisting of entity collections.

I think something like this will work, but there's probably a more efficient way of doing it - please feel free to comment :)

public void PreFlush(System.Collections.ICollection entities)
{
foreach (object entry in entities)
{
Type objType = entry.GetType();
NHibernate.Metadata.IClassMetadata meta = session.SessionFactory.GetClassMetadata(objType);
for (int i = 0; i < meta.PropertyNames.Length; i++)
{
IType propertyType = meta.PropertyTypes[i];
if (propertyType.IsCollectionType)
{
object propertyValue = meta.GetPropertyValue(entry, meta.PropertyNames[i]);
IPersistentCollection persistentCollection = propertyValue as IPersistentCollection;
if (persistentCollection != null && persistentCollection.IsDirty)
{
ICollection snapshot = persistentCollection.CollectionSnapshot.Snapshot;
if (snapshot != null)
{
// Build list of items common to snapshot and current entries
ArrayList commonItems = new ArrayList();
foreach (object snapshotItem in snapshot)
{
foreach (object item in persistentCollection.Entries())
{
if (snapshotItem.Equals(item))
{
commonItems.Add(item);
}
}
}
// Handle deletes
foreach (object snapshotItem in snapshot)
{
if (!commonItems.Contains(snapshotItem))
{

}
}
// Handle inserts
foreach (object item in persistentCollection.Entries())
{
if (!commonItems.Contains(item))
{

}
}
}
}
}
}
}
}