How to pre-fill a NSTableView bound to an ArrayController in a Core Data ( Document based)

Question

Here is my problem: I have a Core Data- Document based program with ARC ( Automatic Reference Counting); I want the tableView shows some data at the beginning. but I receive nothing. Here is what I have done:

1- I made a core data with Entity: MyData

2- then I added a NSArrayController and bound it to managedObjectContext and MyData

3- I bonded the arrayController to col0:

4- then made and outlet and added @synthesize for the arrayController :

5- Finally added this code:

• (void)windowControllerDidLoadNib:(NSWindowController *)aController {

  [super windowControllerDidLoadNib:aController];

  for (NSUInteger i=0; i<5; i++) {

  [myArrayController add:self];
  
  [myArrayController setSelectionIndex: i];
  
  [myArrayController setValue:@"test" forKeyPath:@"selection.col0"];
  
  NSLog(@"%lu",[myArrayController selectionIndex]);
  

  } }

But this is the problem: nothing happens and the SelectionIndex shows strange numbers!!

Any help appreciated

Answer 1

After one month nobody answered me ! finally I could handle it:

NSError* error;

NSInteger count=0;

NSNumber* N=[[NSNumber alloc]initWithInt:0];

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

NSEntityDescription * entityMyData  = [NSEntityDescription entityForName:@"MyData"
                                                  inManagedObjectContext:[self managedObjectContext]];

[fetchRequest setEntity:entityMyData];


count=[self.managedObjectContext countForFetchRequest:fetchRequest error:&error];



    if (count==0 ) {
        

        for (NSInteger i=count+1; i<RowsToAdd+count+1; i++) {

            N=@(i);

            managedObject = [NSEntityDescription insertNewObjectForEntityForName:@"MyData"
                                                          inManagedObjectContext:[self managedObjectContext]];

            [managedObject setValue:N forKey:@"col0"];

            [managedObject setValue:N forKey:@"col1"];

            
        }

       
      
    }