I added a new entity to my model and it loads fine but no changes made in memory get persisted to disk. My values set on the car object work fine in memory but aren't getting persisted to disk on hitting the home button (in simulator). I am using almost exactly the same code on another entity in my application and its values persist to d...
I'm looking to use a dropdown menu (possibly an NSPopupButton object) to represent the hierarchical results of two Core Data entities (Genre and Movie) and their relationships. In my current data model, my Genre entity has a one-to-many relationship with my Movie entity. What I'm now looking to do is generate the contents of an NSPopupB...
I execute a core data fetch which specifies a predicate as follows: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"identifier IN %@", favoritesIDs]; When there are duplicate items in the favoriteIDs array, the fetch request only returns 1 managed object. How can I ensure that more than one instance is fetched? Thank you. ...
I have a class that conforms to UISearchDisplayDelegate and contains a UISearchBar. This view is responsible for allowing the user to poll a store of about 17,000 objects that are currently managed by Core Data. Everytime the user types in a character, I created an instance of a SearchOperation (subclasses NSOperation) that queries Core ...
Hi I have the following piece of code and when I use Instruments/Object Allocations, it tells me that there is a leak there (which goes down to sqlite3MemMalloc). Is there something that I should release? if (![managedObjectContext save:&error]) { NSLog(@"Error while saving."); } The save works well and doesn't trigger an error. ...
Prior art which doesn't quite address this: http://stackoverflow.com/questions/1774359/core-data-migration-error-message-model-does-not-contain-configuration-xyz I have narrowed this down to a specific issue. It takes a minute to set up, though; please bear with me. The gist of the issue is that a persistentStoreCoordinator (apparentl...
I have created an Entity in CoreData that includes a Transformable attribute type implemented as an NSDictionary. The NSDictionary attribute only contains values of a custom class. The properties of the custom class are all of type NSString. The custom class complies with NSCoding implementing: -(void)encodeWithCoder:(NSCoder*)coder;...
In my CoreData Application, I've an outline view on left of main window, acting as source list (like iTunes); on the right I display a proper view, based on outline selection. Each view has its components, such as table view, connected to array controller, owned by the specific view. Very often different views display same data, for exam...
I have the following code which seems to go on indefinitely until the app crashes. It seems to happen with the recursion in the datastructureFromManagedObject method. I suspect that this method: 1) looks at the first managed object and follows any relationship property recursively. 2) examines the object at the other end of the relation...
I am working on application to keep a comic book collection in order. The user should be able to drag an image of the cover artwork into the program via an ImageWell. Since it is not possible to drag the image out of the application again I don't need to save the picture in it's original size. An image at the size of the ImageWell would...
I'm building an app with two tabs. The first tab has a main tableview that connects to a detail view of the row. The second tab will display a tableView based on the user adding content to it by tapping a button on the detail view. My question is this. What is the correct design pattern to do this? Do I create a second ManagedObjectCont...
I am trying to figure out the best way to bulk delete objects inside of my Core Data database. I have some objects with a parent/child relationship. At times I need to "refresh" the parent object by clearing out all of the existing children objects and adding new ones to Core Data. The 'delete all' portion of this operation is where I...
I'm using the following code and I'm getting an EXC_BAD_ACCESS when trying to get the count of objects - anyone have any idea why? Oddly enough, the error only happens if the count should be one or greater, if there are no objects it seems to work fine (it outputs null). NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NS...
I have a deployed app that samples measurements from sensors (e.g., Temp °C, Pressure kPa). The user can create Experiments and collect samples. Each sample is stored as a Run, such that there is a one-to-many relationship from Experiment to Run. In the interest of performance, Run has a to-one relationship with Data entity (which is whe...
I'm using sqlite for the persistent store, so could I just upload the .sqlite file to, for example, Amazon S3 as a way of providing users with the ability to backup their app data? Then for restoring just download it back and replace the existing .sqlite file in the app's folder. Does anybody see any issues with that? Has anyone done it...
I expected the code below to return the objects in imageSet as a sorted array. Instead, there's no difference in the ordering before and after. NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"imageID" ascending:YES]; NSSet *imageSet = collection.images; for (CBImage *image in imageSet) { NSLog(@"imageID in Se...
I'm trying to follow Apple's Core Data utility Tutorial. It was all going nicely, until... The tutorial uses a custom sub-class of NSManagedObject, called 'Run'. Run.h looks like this: #import <Foundation/Foundation.h> #import <CoreData/CoreData.h> @interface Run : NSManagedObject { NSInteger processID; } @property (retain) NSDat...
Hello everyone, I have a tableView that loads its data directly from a Core Data table with a NSFetchedResultsController. I'm not using an intermediate NSMutableArray to store the objects from the fetch results; I basically implemented inside my UITableViewController the protocol method numberOfRowsInSection and it returns the numberOf...
I am working with an app similar to apple's core data recipes sample code. I want to be able to delete the entry from the detail view, much like apple's contacts app. The code below is deleting the 1st entry and not the selected entry. Not sure what I am doing wrong. NSIndexPath *indexPath = [myTableView indexPathForSelectedRow]; NSM...
Part of the app I'm making requires the user to fill in a multi-page form, the contents of which will be saved locally (perhaps using Core Data). Are there any best practices for this? This form just includes text fields. I guess the options are UITextFields, or perhaps a UIWebView, with the fields as part of an html form? Are there are ...