Re: Using an empty string as the default value for a Core Data attribute in the XCode modeller
Re: Using an empty string as the default value for a Core Data attribute in the XCode modeller
- Subject: Re: Using an empty string as the default value for a Core Data attribute in the XCode modeller
- From: Frank Reiff <email@hidden>
- Date: Wed, 5 Sep 2007 14:31:20 +0200
Hi Annard,
Why don't you just subclass NSManagedObject for this entity and set
this value explicitly to an empty string when a new instance is
created using -awakeFromInsert?
Yes, I could do that but I was hoping to avoid creating subclasses
for each and every class that takes an empty string as a default
value.. I'm using Core Data as a database rather than as an
persistent object model, so if there is any way of avoiding doing
this programatically it would really help me out..
Up to now I was using custom classes and a simple XML storage format
in conjunction with Cocoa bindings to get a quick and effective way
of "remembering" UI settings that are too complicated for
NSUserDefaults. This is kind of cool because I can take the settings
and store them into droplets, share them over the internet, etc..
For my latest project I'm using Core Data for overcoming Cocoa's
memory management limitations with very large data sets (instead of
mucking around with NSAutorelease pools and profiler tools). With
this solution even the machine's RAM is no longer a hard limit..
I was quite happy with those developments and given how well Core
Data and Cocoa Bindings seemed to be integrated I thought this might
be an opportunity to get rid of my custom bindings code and make use
of the built-in modelers and validation support.. unfortunately once
I start having to subclass everything, I'm stuck with the same
overhead as before and with more constraints + Apple bugs rather than
my own custom bugs which I prefer ;-)
I'm not keen on having to import the class definitions into each nib
that uses them, writing boiler-plate initialization code, source
manage them, etc..
Still I'm only starting to learn about Core Data and while it looked
like a solution to everything, learning more about its limits early
on might not be a bad thing.. there's still time to ditch it for what
it's no good at and keep it for where it makes sense.
I take it that there simply isn't any way then to put an empty string
as a default value in the modeler? Sigh..
Thanks for your help.
Best regards,
Frank
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