Re: Instance Variables of NSManagedObject Subclasses
On 2011 Jun 30, at 15:36, Allen Ingling wrote: Am I not supposed to add instance variables to NSManagedObject sublcasses? There is no problem in adding instance variables to NSManagedObject subclasses. I have done so many times. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Instance Variables of NSManagedObject Subclasses
Dear cocoa-dev list, I want my NSManagedObjects to retain a variable valid for the lifetime the application instance but not between instances of the application. So I have subclassed NSManagedObject and added an instance variable to the NSManagedObject subclass and defined a property as follows: from the NSManagedObject sublcass header file: @interface KCBMergingManagedObject : NSManagedObject { NSNumber *mergeID; } @property(readwrite, retain) NSNumber *mergeID; and the corresponding .m file contains @synthesize mergeID; Accessing that property has worked but now I have a case where it fails as follows: NSString *foo; NSString *matchValueTemp; foo= entityBTemp.mergeID; matchValueTemp= [entityBTemp valueForKey: @userTypeName]; foo= entityBTemp.mergeID; Here, userTypeName is a field of the entity defined in the core data model and retain by the context. At line three of that that snippet the data of entityBTemp is faulted. The fault is uniqued by accessing userTypeName in the fourth line. In the fifth line, accessing entityBTemp.mergeID causes the application to crash with EXC_BAD_ACCESS. The values returned in variables foo and matchValueTemp in lines 3 and 4 are correct. Am I not supposed to add instance variables to NSManagedObject sublcasses? It does seem like a poor idea from the standpoint that it would interfere with faulting because the data held in the variable and perhaps then also relationships could not be faulted. I can not find anything in Cocoa documentation discussing instance variables in NSManagedObject subclasses. Is it necessary to define transient attribute in the model to get a volatile property in a managed object? Or I could define a new field in the model, retained between app instances, and clear it at application launch. I would like to understand what is going on here though. Allen W. Ingling ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Instance Variables of NSManagedObject Subclasses
Dear cocoa-dev list, I want my NSManagedObjects to retain a variable valid for the lifetime the application instance but not between instances of the application. So I have subclassed NSManagedObject and added an instance variable to the NSManagedObject subclass and defined a property as follows: from the NSManagedObject sublcass header file: @interface KCBMergingManagedObject : NSManagedObject { NSNumber *mergeID; } @property(readwrite, retain) NSNumber *mergeID; and the corresponding .m file contains @synthesize mergeID; Accessing that property has worked but now I have a case where it fails as follows: NSString *foo; NSString *matchValueTemp; foo= entityBTemp.mergeID; matchValueTemp= [entityBTemp valueForKey: @userTypeName]; foo= entityBTemp.mergeID; Here, userTypeName is a field of the entity defined in the core data model and retain by the context. At line three of that that snippet the data of entityBTemp is faulted. The fault is uniqued by accessing userTypeName in the fourth line. In the fifth line, accessing entityBTemp.mergeID causes the application to crash with EXC_BAD_ACCESS. The values returned in variables foo and matchValueTemp in lines 3 and 4 are correct. Am I not supposed to add instance variables to NSManagedObject sublcasses? It does seem like a poor idea from the standpoint that it would interfere with faulting because the data held in the variable and perhaps then also relationships could not be faulted. I can not find anything in Cocoa documentation discussing instance variables in NSManagedObject subclasses. Is it necessary to define transient attribute in the model to get a volatile property in a managed object? Or I could define a new field in the model, retained between app instances, and clear it at application launch. I would like to understand what is going on here though. Allen W. Ingling ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Instance Variables of NSManagedObject Subclasses
Dear cocoa-dev list, I want my NSManagedObjects to retain a variable valid for the lifetime the application instance but not between instances of the application. So I have subclassed NSManagedObject and added an instance variable to the NSManagedObject subclass and defined a property as follows: from the NSManagedObject sublcass header file: @interface KCBMergingManagedObject : NSManagedObject { NSNumber *mergeID; } @property(readwrite, retain) NSNumber *mergeID; and the corresponding .m file contains @synthesize mergeID; Accessing that property has worked but now I have a case where it fails as follows: NSString *foo; NSString *matchValueTemp; foo= entityBTemp.mergeID; matchValueTemp= [entityBTemp valueForKey: @userTypeName]; foo= entityBTemp.mergeID; Here, userTypeName is a field of the entity defined in the core data model and retain by the context. At line three of that that snippet the data of entityBTemp is faulted. The fault is uniqued by accessing userTypeName in the fourth line. In the fifth line, accessing entityBTemp.mergeID causes the application to crash with EXC_BAD_ACCESS. The values returned in variables foo and matchValueTemp in lines 3 and 4 are correct. Am I not supposed to add instance variables to NSManagedObject sublcasses? It does seem like a poor idea from the standpoint that it would interfere with faulting because the data held in the variable and perhaps then also relationships could not be faulted. I can not find anything in Cocoa documentation discussing instance variables in NSManagedObject subclasses. Is it necessary to define transient attribute in the model to get a volatile property in a managed object? Or I could define a new field in the model, retained between app instances, and clear it at application launch. I would like to understand what is going on here though. Allen W. Ingling ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com