Re: core data, boolean attribute, and dynamic
Re: core data, boolean attribute, and dynamic
- Subject: Re: core data, boolean attribute, and dynamic
- From: Martin Hewitson <email@hidden>
- Date: Fri, 12 Aug 2011 20:38:48 +0200
On Aug 12, 2011, at 06:57 PM, Quincey Morris wrote:
> On Aug 12, 2011, at 04:08 , Martin Hewitson wrote:
>
>> In an app I have a core data model which has a File entity which has a boolean attribute isText. This attribute is declared in the corresponding NSManagedObject subclass interface as
>>
>> @property (assign) BOOL isText;
>>
>> and in the implementation I do
>>
>> @dynamic isText;
>>
>> In Lion, accessing this with
>>
>> [file isText]
>>
>> works fine. But it doesn't work on Snow Leopard. There I have to do
>>
>> [[file valueForKey:@"isText"] boolValue]
>>
>> Is this expected behaviour? Was/is something broken on SL that was fixed on Lion? Or is it now broken on Lion?
>
> Yes. No. No.
>
> It's new on Lion that the internal property accessors referenced by @dynamic support scalar types directly. In the past, if you wanted the type of property "isText" to BOOL rather than NSNumber, you had to write a custom getter and setter to make it so.
OK, that explains the observations. I didn't know about this new behaviour on Lion.
>
> For as long as you need to support 10.6 and earlier, I think you'll have to supply the old-style custom implementations.
>
> I don't think I watched the 2011 WWDC video on Core Data, but it's possible this issue is discussed in there, and there may be a more elegant workaround.
I've watched that one and I don't recall this being mentioned, but I'll look back through it because perhaps it just didn't register the first time through.
Thanks for the information!
Martin
>
>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Martin Hewitson
Albert-Einstein-Institut
Max-Planck-Institut fuer
Gravitationsphysik und Universitaet Hannover
Callinstr. 38, 30167 Hannover, Germany
Tel: +49-511-762-17121, Fax: +49-511-762-5861
E-Mail: email@hidden
WWW: http://www.aei.mpg.de/~hewitson
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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