Delete object in Core Data - iphone

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);
}