This is the problem that Partial Entities were attempting to solve ( http://webobjects.mdimension.com/hudson/job/Wonder/javadoc/er/extensions/partials/package-summary.html ). I would consider it experimental, but if anyone wants to take it and finish it, go for it.
ms On May 29, 2012, at 1:40 PM, Ken Anderson <[email protected]> wrote: > Paul, > > My first question would be - how do you actually benefit from having this > data separated? Is there a reason that you don't just create a new entity > for the new project that can represent the entire organization? > > If the reason is that you have code that you would typically use in more than > one project, I would consider building that into POJOs . In general, I find > that the benefits of splitting up entities (either through inheritance OR > composition) seldom outweighs the benefits of having them together, unless > there are some circumstances that totally warrant it. If you could provide > more information on the perceived benefits, people might be able to help you > better. > > Ken > > On May 29, 2012, at 1:16 AM, Paul Hoadley wrote: > >> Hello, >> >> I'm after some general modelling advice. I've been using inheritance for >> years to model app-specific versions of a framework-level Person (user) >> entity. This works well enough, though it presents the same small headaches >> time after time for each new application. >> >> I also have a framework-level Organisation entity to model a user's >> organisation. I need to customise this for a new application, and I thought >> this time I would use composition instead of inheritance—I'll create a new >> FooOrganisation entity which has a to-one relationship to Organisation >> (without the inverse relationship), and then the additional attributes >> and/or relationships which are app-specific. >> >> The application is still in development, but there's a demo deployment, and >> while I _can_ wipe the database, there are existing Organisation EOs in it, >> and it would be nice if I didn't have to. I'm using migrations, so I can >> perform any one-off fix-ups in a post-migration step. >> >> So, do people model like this? Are there any pitfalls? What's the best way >> to ensure referential integrity, such that Organisation and FooOrganisation >> remain 1-1—'owns destination' and 'propagates primary key'? (Selecting >> those will require I scrap the DB and create the FooOrganisations first, >> won't it?) Would dynamically adding some properties to the model at runtime >> be a better option here if I just want to store, say, a few limited extra >> attributes on an entity? >> >> >> -- >> Paul Hoadley >> http://logicsquad.net/ >> >> >> >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Webobjects-dev mailing list ([email protected]) >> Help/Unsubscribe/Update your Subscription: >> https://lists.apple.com/mailman/options/webobjects-dev/kenlists%40anderhome.com >> >> This email sent to [email protected] > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/webobjects-dev/mschrag%40pobox.com > > This email sent to [email protected]
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