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POTrying to initialize ManagedObjectContext from Singleton class in iOS
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  1. POTrying to initialize ManagedObjectContext from Singleton class in iOS
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    copied!<p>I created a Single View Application in iOS that also incorporates Core Data. I moved my .xcdatamodel file from another application and put in to the one I am working on now, and I am having issues. What I have done is cut and paste the code from the previous application and placed it in my AppDelegate.h/m files:</p> <pre><code>@interface DBAppDelegate : UIResponder &lt;UIApplicationDelegate&gt; @property (strong, nonatomic) UIWindow *window; @property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext; @property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel; @property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator; - (void)saveContext; - (NSURL *)applicationDocumentsDirectory; @end </code></pre> <p>and my .m file:</p> <pre><code> @implementation DBAppDelegate @synthesize managedObjectContext = _managedObjectContext; @synthesize managedObjectModel = _managedObjectModel; @synthesize persistentStoreCoordinator = _persistentStoreCoordinator; - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Override point for customization after application launch. UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController; //the line below is what is causing an error DBViewController *controller = (DBViewController *)navigationController.topViewController; controller.managedObjectContext = self.managedObjectContext; return YES; } </code></pre> <p>Within my .m file, I also included the boiler plate code for Core Data that was also in my previous application which I have not posted. In my new application, what I am doing is that I have created an access layer, which also provides a Singleton instance to access this layer. It is in this class where I do my CRUD operations, and have declared the following properties in the .h file:</p> <pre><code>@property (strong, nonatomic) NSManagedObjectContext *managedObjectContext; @property (strong, nonatomic) NSManagedObjectModel *managedObjectModel; @property (strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator; @property (nonatomic, strong) NSFetchedResultsController *fetchedResultsController; </code></pre> <p>At the moment, I am getting the following error:</p> <p>"Property 'managedObjectContext' not found on object of type "DBViewController". What I would like to do is initialize the managedObjectContext inside my method that allows for the creation of a Singleton instance:</p> <pre><code>static DB *sharedSingleton = nil; + (DB *) sharedInstance { if (sharedSingleton == nil) { sharedSingleton = [[super alloc] init]; } return sharedSingleton; } </code></pre> <p>Can anyone see what it is I am doing wrong? I realize I don't declare a managedObjectContext object in my DBViewController, but what do I put in place of this line? I figure it would be something with respect to my Singleton class, but I honestly don't have a clue here.</p> <p>Thanks in advance to all who reply.</p>
 

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