Ios core data not saved - ios

Question

I'm using core data and i have a problem. When i save the data and the app is still running i can see and get the data that was saved.
Once the application is close, all the fields deleted and just the object is saved. I can see that in the saveContext method.
On first launch when the app is closing the saveContext method is activated. I can see that the managedObjectContext object is inserting new object.
The next times that the app is opening , the managedObjectContext is updating the object so i know it save the objects but when i try to retrive the object it can find .
here is how i insert objects:
AppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
self.managedObjectContext = appDelegate.managedObjectContext;
#try {
UserData *userData =[NSEntityDescription insertNewObjectForEntityForName:[UserTable tableName] inManagedObjectContext:self.managedObjectContext];
//Insert Values
userData.facebookId=user.id;
userData.name=user.name;
userData.picoAccessToken=[PicoApiManager sharedInstance].accessToken;
userData.picoExpire=[PicoApiManager sharedInstance].expires;
userData.latitude=[NSNumber numberWithDouble:user.latitude];
userData.longitude=[NSNumber numberWithDouble:user.longitude];
userData.pushId=user.pushId;
userData.isActive=[NSNumber numberWithBool:activeStatus];
}
#catch (NSException *exception) {
NSLog(#"Insert exception - %#", exception.description);
}
or
-(void)addPictures:(NSMutableArray *)Pictures;
{
//Setting the isNew field to NO to all the pictures already in the db
[self updateIsNewOfPicture];
for (Picture *picture in Pictures) {
//Checks if inserted picture is already inside the table
AppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
self.managedObjectContext = appDelegate.managedObjectContext;
#try {
PictureData *pictureData=[NSEntityDescription insertNewObjectForEntityForName:[PicturesTable tableName]inManagedObjectContext:self.managedObjectContext];
//Insert Values
pictureData.url=picture.source;
pictureData.isNew=[NSNumber numberWithBool:YES];
pictureData.isPick=[NSNumber numberWithBool:NO];
pictureData.timeTaken=picture.time_taken;
pictureData.albumData=[self getActiveAlbum];
}
#catch (NSException *exception) {
NSLog(#"Insert exception - %#", exception.description);
}
}
This is app delegate functions:
- (void)saveContext
{
NSError *error = nil;
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if (managedObjectContext != nil) {
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
}
}
}
#pragma mark - Core Data stack
// Returns the managed object context for the application.
// If the context doesn't already exist, it is created and bound to the persistent store coordinator for the application.
- (NSManagedObjectContext *)managedObjectContext
{
if (_managedObjectContext != nil) {
return _managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
_managedObjectContext = [[NSManagedObjectContext alloc] init];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
}
return _managedObjectContext;
}
// Returns the managed object model for the application.
// If the model doesn't already exist, it is created from the application's model.
- (NSManagedObjectModel *)managedObjectModel
{
if (_managedObjectModel != nil) {
return _managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:#"Pico-Db" withExtension:#"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
// Returns the persistent store coordinator for the application.
// If the coordinator doesn't already exist, it is created and the application's store added to it.
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (_persistentStoreCoordinator != nil) {
return _persistentStoreCoordinator;
}
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"Pico.sqlite"];
NSError *error = nil;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return _persistentStoreCoordinator;
}
// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
This is how i'm trying to get the data :
AppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
//2
// initializing NSFetchRequest
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
//Setting Entity to be Queried
NSEntityDescription *entity = [NSEntityDescription entityForName:[UserTable tableName] inManagedObjectContext:appDelegate.managedObjectContext];
[fetchRequest setEntity:entity];
NSError* error;
// Query on managedObjectContext With Generated fetchRequest
NSArray *fetchedRecords = [appDelegate.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (fetchedRecords.count >0) {
return YES;
}
return NO;

Answer 1

You must call -[AppDelegate saveContext] after inserting your data in order for CoreData to persist changes to disk. The NSManagedObjectContext will store changes in memory so while your application is still active, you will have access to the data. As soon as the app terminates, however, unless you call -[AppDelegate saveContext] those changes will not be persisted.
Try this in the first example:
AppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
self.managedObjectContext = appDelegate.managedObjectContext;
#try {
UserData *userData = [NSEntityDescription insertNewObjectForEntityForName:[UserTable tableName] inManagedObjectContext:self.managedObjectContext];
//Insert Values
userData.facebookId=user.id;
userData.name=user.name;
userData.picoAccessToken=[PicoApiManager sharedInstance].accessToken;
userData.picoExpire=[PicoApiManager sharedInstance].expires;
userData.latitude=[NSNumber numberWithDouble:user.latitude];
userData.longitude=[NSNumber numberWithDouble:user.longitude];
userData.pushId=user.pushId;
userData.isActive=[NSNumber numberWithBool:activeStatus];
} #catch (NSException *exception) {
NSLog(#"Insert exception - %#", exception.description);
}
// SAVE CONTEXT:
[appDelegate saveContext];
Try this in the second example:
for (Picture *picture in Pictures) {
// Checks if inserted picture is already inside the table
AppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
self.managedObjectContext = appDelegate.managedObjectContext;
#try {
PictureData *pictureData = [NSEntityDescription insertNewObjectForEntityForName:[PicturesTable tableName]inManagedObjectContext:self.managedObjectContext];
//Insert Values
pictureData.url=picture.source;
pictureData.isNew=[NSNumber numberWithBool:YES];
pictureData.isPick=[NSNumber numberWithBool:NO];
pictureData.timeTaken=picture.time_taken;
pictureData.albumData=[self getActiveAlbum];
} #catch (NSException *exception) {
NSLog(#"Insert exception - %#", exception.description);
}
}
// SAVE CONTEXT:
[appDelegate saveContext];
To create a fetch request:
NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:#"YourEntityName"];
request.sortDescriptors = [NSSortDescriptor sortDescriptorWithKey:#"attributeName" ascending:YES];
request.predicate = [NSPredicate predicateWithFormat:#"attribute == %#", 13];
NSError *error = nil; //
NSArray *results = [appDelegate.managedObjectContext executeFetchRequest:request error:&error];
if (!results) {
NSLog(#"Error performing fetch request: %#", error.localizedDescription);
}
return ([results count] > 0); // There are more efficient ways of getting count from CoreData