Re: ADC Core Data article

FROM : mmalcolm crawford
DATE : Thu Apr 07 00:50:30 2005

On Apr 6, 2005, at 3:25 PM, Timothy Reaves wrote:

> I've seen no one comment on what looks to be rather nasty: it 
> appears that
> the only way to use CoreData is to access the values via KVC.


I didn't see anything in the article that makes that assertion?

The article does say, "The NSManagedObject class implements the 
functionality needed to fully integrate into the Core Data framework 
and can represent any entity. It acts as a dictionary in that any of 
its attributes and relationships can be set using Key-Value Coding 
(KVC) as well as observed using Key-Value Observing (KVO)."

But it also states (immediately before), "By default, the class used 
is NSManagedObject, but the class may be either NSManagedObject or a 
subclass thereof."

KVC is a generic technology that allows you to access an object's 
properties using the property name as a string.  It's can be used 
with any object.  KVC provides a number of ways the data can be 
retrieved.  I don't see that the material in the article asserts that 
"the *only way* to use CoreData is to access the values via KVC."

Looking at the EOF documentation (purely for historical interest), 
EOF provided an EOGenericRecord class that appears to be an analogue 
of NSManagedObject.  It had private internal storage and could 
represent any entity.  You accessed properties using key-value 
coding.  You could also, however, subclass EOGenericRecord and use 
explicit instance variables and custom accessor methods if you 
wished.  You could still access these properties using KVC...

mmalc