How can I set a Custom attribute of an NSManagedObject which is calculated from other attributes?

I am using core data framework to manage objects. I have an entity which has several attributes of decimal types. Among them is an attribute开发者_StackOverflow中文版 which is mathematically calculate

insertNewObjectForEntityForName:inManagedObjectContext: returning NSNumber bug?

I\'m relatively well versed in CoreData and have been using it for several years with little or no difficulty. For the life of me, I can\'t figure out why

iPhone - Change entity class (NSManagedObject) to make them initializable

I would like to use my custom NSManagedObject like 开发者_如何学Goa normal object (as well as its regular functions). Is it possible to modify the class in order to be able to initialize it like a nor

Core Data - How to check if a managed object's properties have been deallocated?

I\'ve created a program that uses core data and it works beautifully. I\'ve since attempted to move all my core data methods calls and fetch routines into a class that is self contained.My main progr

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How to check existence of reference to an NSManagedObject?

I successfully stored and retrieved a reference to an NSManagedObject using the example found in this site http://cocoawithlove.com/2008/08/safely-fetching-nsmanagedobject-by-uri.html

Problem with the name of an NSEntityDescription

This problem follows on from a previous question. When I run the following line of code: NSEntityDescription *outputCellEntityDescription = [NSEntityDescription entityForName:@\"OutputCell\"

How to retrieve stored reference to an NSManagedObject subclass?

I have a NSManagedObject subclass named Tour. I stored the reference to it using this code: prefs = [NSUserDefaults standardUserDefaults];

How can I track/observe all changes within a subgraph?

I have a NSManagedObjectContext in which I have a number of subclasses of NSManagedObjects such that some are containers for others.What I\'d like to do is watch a top-level ob开发者_运维技巧ject to b

Core Data: editing object from detail view

I\'m just starting out with Core Data and I have an iPhone Core Data project set up in a master-detail view system. The master view contains items, and the detail view lets you edit the properties of