Delete object in Core Data

Question

How I can delete an object which I had added before with this code. Its a favorites section, in the begin, I add a gray star which adds an object coming from a fetch. Then It turns yellow and the backwards method should be star yellow = deletes.

But I have no idea how to do this.

-(IBAction)inFavoris:(id)sender {    AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];  NSManagedObjectContext *context = [appDelegate managedObjectContext]; NSManagedObject *favorisObj = [NSEntityDescription                             insertNewObjectForEntityForName:@"Favoris"                             inManagedObjectContext:context];   [favorisObj setValue:idTaxi forKey:@"idTaxi"]; [favorisObj setValue:nomTaxi forKey:@"nomTaxi"]; [favorisObj setValue:taxiCB forKey:@"cb"]; [favorisObj setValue:taxiAvion forKey:@"avion"]; [favorisObj setValue:taxiColis forKey:@"colis"]; [favorisObj setValue:taxiHandicape forKey:@"handicape"]; [favorisObj setValue:taxiHoraires forKey:@"horaire"]; [favorisObj setValue:lugagge forKey:@"lugagge"]; [favorisObj setValue:luxury forKey:@"luxury"]; [favorisObj setValue:languesParlees forKey:@"langues"]; [favorisObj setValue:taxiNote forKey:@"note"]; [favorisObj setValue:taxiPassengers forKey:@"passenger"]; [favorisObj setValue:taxiVote forKey:@"etoiles"]; [favorisObj setValue:taxiTel forKey:@"tel"];   [self.view addSubview:favorisB];  } 

UPDATE

I made this method.. It gets the job done :)

-(IBAction)outFavoris:(id)sender {   AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]; NSString *testEntityId = idTaxi; NSManagedObjectContext *moc2 = [appDelegate managedObjectContext];  NSFetchRequest *fetch = [[NSFetchRequest alloc] init]; fetch.entity = [NSEntityDescription entityForName:@"Favoris" inManagedObjectContext:moc2]; fetch.predicate = [NSPredicate predicateWithFormat:@"idTaxi == %@", testEntityId]; NSArray *array = [moc2 executeFetchRequest:fetch error:nil];     for (NSManagedObject *managedObject in array) {     [moc2 deleteObject:managedObject]; }   [self.view addSubview:favorisO];  }  

Answer 1

Its quite simple :)

[context deleteObject:favorisObj]; 

And the bad object is all gone.

Update

You'd just reverse it with something like this if you need a button to delete the object.

-(IBAction)removeFavoris:(id)sender {      AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];      NSManagedObjectContext *context = [appDelegate managedObjectContext];      [context deleteObject:favorisObj]; } 

Answer 2

Don't forget to save the Context after you have deleted a NSManagedObject. So here is the general code;

NSManagedObjectContext * context = [self managedObjectContext]; [context deleteObject:objectToDelete];  NSError * error = nil; if (![context save:&error]) {     NSLog(@"Error ! %@", error); } 

In your case it should have the snippet after the for loop.

for (NSManagedObject *managedObject in array) {     [moc2 deleteObject:managedObject]; } NSError * error = nil; if (![context save:&error]) {     NSLog(@"Error ! %@", error); }