But how do you protect your collection from being changed; exposing it as read-only? But that is not intuitive, if client does not know that AddPerson is to be used you would get exception. Why is #2 not viable?
On Dec 18, 9:29 pm, "Greg Young" <[email protected]> wrote: > 1. don't let collection be modified directly but use Add/remove and > enforce rule there > > Have the aggregate root enforce the validation. > > Cheers, > > Greg > > > > On Thu, Dec 18, 2008 at 7:25 PM, epitka <[email protected]> wrote: > > > This is probably more a DDD question then NH. Let say you have > > observable collections that raise events before collection gets > > changed and after. Let's say you have a rule that only person's over > > 21 can be added to the collection. How would you handle this rule: > > 1. don't let collection be modified directly but use Add/remove and > > enforce rule there > > 2. create delegate that will check rule in OnChanging step and veto > > change > > 3. allow person to be added and run validate before persisting entity > > using NH events, basically allow entity to get into invalid state > > 4. manually invoke validation before commiting changes. > > 5. something else ? > > -- > It is the mark of an educated mind to be able to entertain a thought > without accepting it. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nhusers?hl=en -~----------~----~----~----~------~----~------~--~---
