c# - NHibernate 3.2 - Pre and Post Delete event listeners not invoked -

i working against implementation of nhibernate 3.2 several custom entity state change listeners: predelete, delete, , postdelete. deleteeventlistener defined inheriting custom type defaultdeleteeventlistener, others implementing ieventlistener interfaces.

the body of customdeleteeventlistener follows:

protected override void deleteentity(ieventsource session, object entity, entityentry entityentry, bool iscascadedeleteenabled, ientitypersister persister, iset transiententities) {     if (entity baseentity)         handleentityassociations(session, (baseentity)entity);      if (entity isoftdeletable)      {           var e = (isoftdeletable)entity;         utility.settrackinginfo(e basemodel);          e.deleted = true;           cascadebeforedelete(session, persister, entity, entityentry, transiententities);          cascadeafterdelete(session, persister, entity, transiententities);      }      else      {          base.deleteentity(session, entity, entityentry, iscascadedeleteenabled, persister, transiententities);      }  } 

in tests, i've found ondelete() listener called before onpredelete() , onpostdelete() listeners, , pre , post listeners never fire if base.deleteentity() not called. doesn't make sense me- expect order be: onpredelete(), ondelete(), onpostdelete().

when examined callstack, noticed ondeleteevent() triggered underlying call firedelete() invoked after call isession.delete(), onpredeleteevent() fired listener onflush()- disconnected call ondeleteevent().

there no documentation these listeners, handful of blogs using them this-and-that. know how these work in nhibernate 3.2, , why seeing behaviors am?

from understand, ondelete, onupdate, ... used things validation, or modify actual entity being deleted, updated, inserted. occurs pretty @ start of pipeline, see e.g. "nhibernate interceptor magic tricks, pt. 4"

when delete occurres, first thing nhibernate does, calling iinterceptor.ondelete(object entity, object id, object[] state, string[] propertynames, itype[] types) method. not provide flow control , called default ideleteeventlistener before scheduling real delete action.

also refer other parts of blog series more information.

the predelete , postdelete event listeners called in deleteaction, created defaultdeleteeventlistener (i.e. class deriving from) in deleteentity method, , added session's action queue. invoked after deleteeventlistener invokation.

the pre... events happen before actual command being issued. @ point late force changes command modifying entities themselves, although can work command's parameters (and make sure apply changes corresponding entity's fields), or perform additional action (e.g. insert audit record) using child session. returning true of these pre... listeners veto change, returning false result in executing it.

you may want read blog post: nhibernate ipreupdateeventlistener & ipreinserteventlistener. relates update , insert listeners, delete, reasoning similar.

those allow execute our custom logic before update / insert sent database. on face of it, seems trivial task, there subtleties need consider when use them.

those hooks run awfully late in processing pipeline, part of make them useful, because run late, when use them, have aware doing them , how impacts rest of application.

it appears "awfully late" means:

the ado.net command executed event listener finish running.

since nhibernate has roots firmly in java hibernate version, has same type of listeners , events, potential source of information more official documentation on topic.