Re: How to store NSRect as Core Data attribute?

FROM : Ben Lachman
DATE : Wed Apr 02 18:12:41 2008

I think the easiest way to encode/decode NSRects for storage is 
NSStringFromRect() and NSRectFromString().  Then you can just 
implement a custom accessor for the property that converts in the 
direction you need.

->Ben
--
Ben Lachman
Acacia Tree Software

http://acaciatreesoftware.com

<email_removed>
740.590.0009



On Apr 2, 2008, at 7:28 AM, Daniel Thorpe wrote:
> Hello everyone,
>
> I'm trying to get to grips with non-standard persistent attributes 
> in Core Data. I've read through the docs I can find (http://
> developer.apple.com/documentation/Cocoa/Conceptual/CoreData/
> Articles/cdNSAttributes.html)  but I'm still having some issues 
> storing an NSRect in an entity. I've set the type to be 
> transformable, and left the value transformer field empty using the 
> model editor.
>
> To actually set and get the NSRect values, I've been using 
> NSValue's valueWithRect: and rectValue methods. However, when CD 
> trys to saving the entities to the store, I get this error:
>
> *** -[NSKeyedArchiver encodeValueOfObjCType:at:]: this archiver 
> cannot encode structs
>
> I've also changed the property defined in the header file for the 
> entity to:
> @property(retain) NSValue *extent;
>
> from
> @property(retain) id extent;
>
> What am I doing wrong here? The docs seem to suggest for KVO/KVC 
> compliant structs, NSRect, NSPoint, NSSize and NSRange, you don't 
> need to overwrite the getters and setters?
>
> Any help is much appreciated!
>
> Cheers
> Dan
>
>
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