nsmanagedobject

Seemingly inconsistent behavior among NSManagedObject subclasses

I have several subclasses of NSManagedObject. They are all instantiated with code something like this: MeasurementDescriptor *descriptor = (MeasurementDescriptor *)[NSEntityDescription insertNewObjectForEntityForName:@"MeasurementDescriptor" inM...

How to set NSManagedObjectID manually?

I want to sync the Core Data on iPhone with MongoDB on Sinatra server. When the iPhone gets a message from the Node.js chat server, the message contains the sender's BSON ObjectId (a string). For the iPhone to store this message, I find the user with that same Id in Core Data. I want to be able to do something like objectWithID. In othe...

What are all the steps should be taken while shifting a core data programs location?

Hi friends, I did a program using core data and saved it in my desktop. The entities, relationships are available in .xcdatamodel file. Then i copied my entire program into some other folder in disk and erased the original file placed in desktop. Now the copied program did not work. The managed objects are null. What changes must i do ...

Is it possible to have Core Data sort the "many" part of a To-Many relationship during a fetch request?

I'm using Core Data to cache a decent amount of information, and I have a To-Many relationship set up among my managed objects. Naturally I use an NSFetchRequest to fetch an array of the singular side of that relationship. However, I populate a UITableView using the the "many" side of the relationship, and I'd like it to be sorted alphab...

Saving an instance of an NSManagedObjectContext does not permanently save a mutable transformable attribute

I'm using Core Data + sqlite as a data cache. The app reads in a file into core data, then uses Core Data to run the app. Saves are done to both the NSManagedObjectContext and to the file. I've noticed, though, if I quit the app and reload it without repopulating the Core Data database, some (but not all) of the data saved using -save: i...