Question

My AppDelegate.h:

#import <UIKit/UIKit.h>
#import "Child.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate> {
    NSManagedObjectModel *managedObjectModel;
    NSManagedObjectContext *managedObjectContext;
    NSPersistentStoreCoordinator *persistentStoreCoordinator;
}
@property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;
@property (readonly, retain, nonatomic) NSManagedObjectModel *managedObjectModel;
@property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;
- (NSString *)applicationDocumentsDirectory;
@property (strong, nonatomic) UIWindow *window;
@end

AppDelegate.m:

#import "AppDelegate.h"
@implementation AppDelegate

@synthesize managedObjectContext = __managedObjectContext;
@synthesize managedObjectModel = __managedObjectModel;
@synthesize persistentStoreCoordinator = __persistentStoreCoordinator;
@synthesize window = _window;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    NSManagedObjectContext *context = [self managedObjectContext];
    if (!context) {
        NSLog(@"Error");
    }
    return YES;
}
- (void)applicationWillTerminate:(UIApplication *)application { /* Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:. */
    NSError *error;
    if (managedObjectContext != nil) {
        if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
        // Handle the error.
        } 
    }
}
// Explicitly write Core Data accessors
- (NSManagedObjectContext *) managedObjectContext {
    if (managedObjectContext != nil) {
        return managedObjectContext;
    }
    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        managedObjectContext = [[NSManagedObjectContext alloc] init];
        [managedObjectContext setPersistentStoreCoordinator: coordinator];
    }
    return managedObjectContext;
}
- (NSManagedObjectModel *)managedObjectModel {
    if (managedObjectModel != nil) {
        return managedObjectModel;
    }
    managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
    return managedObjectModel;
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
    if (persistentStoreCoordinator != nil) {
        return persistentStoreCoordinator;
    }
    NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"iSalahProject.sqlite"]];
    NSError *error = nil;
    persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if(![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) {
        /*Error for store creation should be handled in here*/
    }
    return persistentStoreCoordinator;
}
- (NSString *)applicationDocumentsDirectory {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
    return basePath;
}
@end

My controller implementation class where entity is being created and I am getting the error:

-(IBAction)addChildren:(id)sender{
    inputChildName = nameOfChild.text;
    NSManagedObjectContext *context = [app managedObjectContext];
    Child * childrenName = [NSEntityDescription insertNewObjectForEntityForName:@"Child" inManagedObjectContext:context];
    childrenName.name = inputChildName;
}

The error I am getting is:

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '+entityForName: could not locate an NSManagedObjectModel for entity name 'Child''

I am using iOS-5 XCode 4.2 ARC. Please help me resolving this issue, I already have spent hours resolving it, but I couldn’t find any solutions.

Answer 1

Your application is terminating because your managedObjectContext is nil. Check for it and if its nil copy it from delegate. You can use this if condition in your -(IBAction)addChildren:(id)sender method

if (managedObjectContext == nil) 
{ 
    managedObjectContext = [(CoreDataBooksAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
    NSLog(@"After managedObjectContext: %@",  managedObjectContext);
}