Re: Delete rule "deny"
Re: Delete rule "deny"
- Subject: Re: Delete rule "deny"
- From: Kaspar Fischer <email@hidden>
- Date: Mon, 20 Jun 2005 13:38:39 +0200
And let me note that validateForDelete *only* checks whether
the object in question is part of a relationship with a
"deny" delete rule. So if the model was something like this
A <---->> B <---->> C
cascade deny
where (as indicated) the former relationship has a "cascade"
and the latter a "deny" rule, then an attempt to delete an
instance a of A which relates to an instance b of B which in
turn relates to an instance c of C will not succeed (because
b cannot be deleted). Nonetheless,
[a validateForDelete:&error]
returns YES. (I tried this out.)
Could someone explain the rationale behind this? In my
application, I need a routine "validateGloballyForDelete"
which checks on the whole object graph.
On 20.06.2005, at 11:10, mmalcolm crawford wrote:
On Jun 20, 2005, at 1:39 AM, Kaspar Fischer wrote:
So does anybody know how one can prevent an object
from being deleted if the deletion would violate
(on an imaginary "Save" operation) a Deny rule?
You can't. You could, however, simply invoke validateForDelete
prior to attempting to delete (and don't delete if it returns NO)...
"Determines whether the receiver can be deleted in its current
state, returning YES if it can, otherwise NO and in error an
NSError that describes the problem. For example, an object can’t be
deleted if it has a relationship has a “deny” delete rule and that
relationship has a destination object."
<http://developer.apple.com/documentation/Cocoa/Reference/
CoreData_ObjC/Classes/NSManagedObject.html#//apple_ref/doc/uid/
TP30001171-BBCJCJBF>
mmalc
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden