Re: ADC Core Data article

FROM : Ondra Cada
DATE : Wed Apr 06 04:04:07 2005

Jake,

On 6.4.2005, at 2:31, Jake Macmullin wrote:

> However, other O/R frameworks allow you to persist 'plain old'
> objects. For example, Hibernate allows you to persist 'plain old Java
> objects' - so I'm not sure it is asking too much for an O/R framework
> which doesn't require that all persisted classes inherit from a common
> parent (other than object). Although perhaps some of Core Data's
> features such as the handling of 'undo and redo' would make this idea
> more difficult.


Managed objects (among others) actually *store* the attributes and
relationships ("The NSManagedObject ... acts as a dictionary"): that
would be one of the main features which needs an extra class.

Just cosnider this: a managed object would have to contain some kind of
a dictionary to contain the data themselves. Judging by the EOF
example, there probably would be also a link to its entity descriptor
(whatever class it is defined by--might be a dictionary, too, if
simplified enough) to define the data structure. Another link would be
needed to the object's EOEditingContext -- sorry,
NSManagedObjectContext :)) -- and so forth.

It would be too much to suppose all these things would be part of
NSObject, would it not?

On the other hand, if you don't need all these services and just aim
for persistence, CoreData aren't what you need: just use an NSArchiver,
and you get the support for any NSObject :))
---
Ondra Èada
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