I have 2 entities. entity A will hold many entity Bs and order will matter. if i check the little box that says 'indexed' in xcode, how do i go about using that index, if i even can? ( i know that i CAN use it in some way: http://cocoawithlove.com/2008/03/testing-core-data-with-very-big.html but i am not so spiffy with Obj-c yet.) I h...
Hello, I'm trying to save an array to Core Data. I've been reviewing the following thread: http://stackoverflow.com/questions/537044/storing-custom-objects-in-an-nsmutablearray-in-nsuserdefaults (in particular the answer from Stefan). My code is as follows: for (TempWorkout *newTempWorkout in items) { NSString *st...
I started learning core data and I wanted to do a simple category->object->detail application. I started with the location tutorial. After I've done it, I moved all the auto-generated code from my appDelegate to a new DataProvider class and i put a tabbar at the beginning of the app. So I have a TableView tabbar item (with a navigation c...
Hi. I'm creating an iphone/ipad app that basically reads XML documents and creates tableviews from objects created based on the xml. The xml represents a 'level' in a filesystem. Its basically a browser. Each time i parse the xml documents i update the filesystem which is mirrored in a core-data sqllite database. For each "File" encou...
Using the Employees-Departments example what I want to do is bind a column to "[email protected]" as outlined below: Entity Employee attributes: "firstName", "lastName", "hoursWorked" relationship: "departments" Entity Department attributes: "name" relationship: "employees" I want a table wh...
So I got entities Level and Tile. Level has a to-many relationship with Tile. Tile has a property 'index'. Right now I'm using this code to get the tiles array of Level sorted: - (NSArray *)sortedTiles { NSMutableArray *sortedTiles = [NSMutableArray arrayWithArray:[self.tiles allObjects]]; NSSortDescriptor *sortDescriptor...
I have a CoreData model (managed object) called Item: @interface Item : NSManagedObject { NSString * type; } @property (retain) NSString * type; @end I also have two subclasses of Item: @interface Circle : Item @end @interface Square : Item @end I track the subclass of the item by the type property. When I fetch my Items, I ge...
In XCocde when you create a data model diagram, it will also generate the classes for each entities in the diagram which inherit from NSManagedObject. The question is are these classes considered my "Model" classes? OR are they just a bridge between my core data and model classes? PLease if you have a good tutorial let me know, i've be...
So I'm making an iphone app that just has a thousand entries that I'm reading from an xml file into core data. But inserting these records takes like 10 seconds on the device. It's pretty ridiculous. The schema is very simple, just one table. I.e., no relationships or anything. To see what I mean, you can just go to: 1. File -> New Pr...
Hi All, My problem is I have an array of objects of size N. after every time (t+1), some of the values of the array may or may not change. so lets say t+1 index 15 changes but everything else stays the same. What is the most efficient way to store something like this (in memory ) apart from just having an array of arrays of course? I w...
Hi, my app is based around two classes: Jam and JamItem, each with a TableViewController to display / add items. The model contains two entities for the two classes, and there is an optional one-to-one relationship between them. JamItem has a name field and a price field. Jam has a quantity field. There are corresponding NSManagedObject...
This is a really strange problem I'm seeing in my app. I have an NSTextField bound to an attribute of an NSManagedObject, but whenever the object is saved the textfield loses focus. I'm continuously updating the value of the binding, so this is far from ideal. Has anyone seen anything like this before, and (hopefully) found a solution? ...
The 'Like' is pretty simple it seems, it only supports ? and * I believe, kind of like old-school wildcards. But I want to do this: Find all words that begin with a given range of characters... for example a-j. So I got it to find all words that start with say, the letter j: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"...
Hi there, I did some changes at my CoreData Model. So far, I added a attribute called 'language'. When my application is launched and I click on "Create new Customer" a instance variable Customer is created. This variable is created by: Customer *newCustomer = [NSEntityDescription insertNewObjectForEntityForName:@"Customer" inManagedOb...
Apple's recommended method for multithreading core data is to use a managed object context per thread, and to send changes from one context to another by saving the changed thread's context to a shared persistent store. While I can imagine that being fine for, eg. an RSS reader, for some applications it seems far from ideal. In my case,...
I'm having a problem in my application, CoreData works as it should in he simulator - but not on the device. I receive an 2010-09-30 12:45:07.500 CoreDataTutorial_iOS[130:307] Unresolved error Error Domain=NSCocoaErrorDomain Code=513 "The operation couldn’t be completed. (Cocoa error 513.)" UserInfo=0x1412a0 {NSUnderlyingException=Err...
I currently have a 'Topic' entity defined in my system as: @interface Topic : NSManagedObject { } @property (nonatomic, retain) NSString * path; @property (nonatomic, retain) NSString * name; @property (nonatomic, retain) NSNumber * topicID; @property (nonatomic, retain) NSNumber * parent; @end I want to fetch a topic with a specif...
I need to support full text search for a 10 mb document and wondering if I should implement FTS with CoreData or Sqlite3. I am familiar with CoreData and not too fond of Sqlite3. Anyone with experience care to enlighten me? What other options do i have? Thanks! ...
I have three core data entities which I am importing into, they are: • sizes (Name, Clothes (one to many with "Clothes" entity)) • Clothes (Name, Price, etc... +2 relationships) • shop (Name, Clothes (one to many to "Clothes" entity)) I have imported shops, into shop and sizes into the sizes entity. Now I am importing the clothes. ...
I am having problems with the context in Core Data not being able to save. I get random crashes when I try to call [context save:]. Sometimes it works, sometimes it doesn't and crashes the app. Here is my delete code. I have been able to reduce the number of crashes by checking if [context respondsToSelector] save. The strange this is e...