Hi Kieran, Do you store the name of the java class or use a lookup hashmap or something else?
Mark On 1 April 2010 11:52, Kieran Kelleher <kieran_li...@mac.com> wrote: > For sure, Roles are the way to go, especially if someone can have more than > one Role (outside of the game of Chess, can a King also be a Knight? ;-) ) > However if your design really has only one Role and you don't want to or > can't change your database schema, you could drop the inheritance on those > entities and use the Strategy Design pattern to lazily instantiate composited > behaviours .... PeasantBehaviour, KingBehaviour, KnightBehaviour that all > implement the RoleBehaviour interface (in American english, drop the 'u' in > "behaviour".) You don't even need to change the current database. Just use > the current inheritance 'type' field to map to a RoleBehaviour class..... and > now the RoleBehaviour becomes an attribute. The work involved is just EOModel > simplification and breaking out the behaviours into classes > > YMMV, Kieran > > > On Mar 31, 2010, at 10:48 PM, Ramsey Lee Gurley wrote: > >> I can't see this being possible in Vertical or Horizontal, but with single >> table... could the qualifying attribute be updated to 'promote' an entity to >> a new class? Let's say we have we have an abstract Person entity with three >> subclasses, Peasant, Knight, King. If I wanted to promote a knight to king, >> is it possible to simply update my type attribute from knight to king and >> EOF will start treating that record as a king instead of a knight? I would >> assume I would need to invalidate the existing knight object after saving >> changes so it could be refetched as a king... and if I had multiple >> instances, I'd need to invalidate it in those instances too... but is it >> possible? Or will EOF just flip out in the saveChanges() and refuse to do >> it? >> >> Just an academic question, of course (^_^) >> >> Ramsey _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) >> Help/Unsubscribe/Update your Subscription: >> http://lists.apple.com/mailman/options/webobjects-dev/kieran_lists%40mac.com >> >> This email sent to kieran_li...@mac.com > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/webobjects-dev/mark%40wardle.org > > This email sent to m...@wardle.org > > -- Dr. Mark Wardle Specialist registrar, Neurology Cardiff, UK _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
