Hi guys,
I am using XCode 9.
I get this error that I’ve seen on the forum other people have, but they are all using older versions of XCode, when CoreData was creating different code in the AppDelegate.m
I’ve followed the videos in module 7 and I can’t figure out what I am missing…
This is the code from my AppDelegate.m:
-
(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
ViewController *rootVC = (ViewController *)_window.rootViewController;
rootVC.myContext = _persistentContainer.viewContext;return YES;
}
#pragma mark - Core Data stack
@synthesize persistentContainer = _persistentContainer;
-
(NSPersistentContainer *)persistentContainer {
// The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it.
@synchronized (self) {
if (_persistentContainer == nil) {
_persistentContainer = [[NSPersistentContainer alloc] initWithName:@“tableViewCoreData”];
[_persistentContainer loadPersistentStoresWithCompletionHandler:^(NSPersistentStoreDescription *storeDescription, NSError *error) {
if (error != nil) {
// 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./* Typical reasons for an error here include: * The parent directory does not exist, cannot be created, or disallows writing. * The persistent store is not accessible, due to permissions or data protection when the device is locked. * The device is out of space. * The store could not be migrated to the current model version. Check the error message to determine what the actual problem was. */ NSLog(@"Unresolved error %@, %@", error, error.userInfo); abort(); } }]; }}
return _persistentContainer;
}
#pragma mark - Core Data Saving support
- (void)saveContext {
NSManagedObjectContext *context = self.persistentContainer.viewContext;
NSError *error = nil;
if ([context hasChanges] && ![context 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);
abort();
}
}
And this is from ViewController.m
@interface ViewController () <UITableViewDelegate, UITableViewDataSource, NSFetchedResultsControllerDelegate>
@property (weak, nonatomic) IBOutlet UITableView *tableView;
@property (weak, nonatomic) IBOutlet UITextField *textField;
@property (strong,nonatomic) NSFetchedResultsController *resultsController;
@end
@implementation ViewController
-
(void)viewDidLoad {
[super viewDidLoad];// NSFetchedResultsController delegate
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];fetchRequest.entity = [NSEntityDescription entityForName:@“ToDoEntity” inManagedObjectContext:_myContext];
fetchRequest.predicate = [NSPredicate predicateWithFormat:@“TRUEPREDICATE”];
fetchRequest.sortDescriptors = @[[[NSSortDescriptor alloc] initWithKey:@“title” ascending:YES]];
_resultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:_myContext sectionNameKeyPath:nil cacheName:nil];
_resultsController.delegate = self;NSError *err;
BOOL fetchSucceeded = [_resultsController performFetch:&err];
if(!fetchSucceeded){
@throw [NSException exceptionWithName:NSGenericException reason:@“Could’t fetch!” userInfo:@{NSUnderlyingErrorKey:err}];
}
}
-
(IBAction)todoTapped:(id)sender {
// Get the text
NSString *text = _textField.text;
NSManagedObjectContext *ctx = _myContext;// Store the text in a CoreData object
ToDoEntity *item = [NSEntityDescription insertNewObjectForEntityForName:@“ToDoEntity” inManagedObjectContext:ctx];
item.title = text;// Save the CoreData object
NSError *err;
BOOL saveSuccess = [ctx save:&err];
if (!saveSuccess){
@throw [NSException exceptionWithName:NSGenericException reason:@“Could’t save!” userInfo:@{NSUnderlyingErrorKey:err}];
}
else{
_textField.text = nil;
}
}
#pragma mark - TableView Delegates
-(NSInteger) numberOfSectionsInTableView:(UITableView *)tableView{
return 1;
}
-(NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return _resultsController.sections[section].numberOfObjects;
}
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
ToDoEntity *item = _resultsController.sections[indexPath.section].objects[indexPath.row];
TableViewCell *cell = (TableViewCell *) [tableView dequeueReusableCellWithIdentifier:@"TableCell" forIndexPath:indexPath];
[cell setTitle:item];
return cell;
}
#pragma mark - NSFetchedResultsControllerDelegate
-(void) controllerWillChangeContent:(NSFetchedResultsController *)controller{
[_tableView beginUpdates];
}
-(void) controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath{
switch(type) {
case NSFetchedResultsChangeInsert:
[_tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[_tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:{
TableViewCell *cell = [_tableView cellForRowAtIndexPath:indexPath];
ToDoEntity *item = [controller objectAtIndexPath:indexPath];
[cell setTitle:item];
break;
}
case NSFetchedResultsChangeMove:
[_tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
[_tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
-(void) controllerDidChangeContent:(NSFetchedResultsController *)controller{
[_tableView endUpdates];
}
I tried to change some things here and there, but nothing worked…
I’m missing something and can’t figure out what.
Anybody has an idea?
Thank you,
Mircea
, is that you need to add this code: