Question

I want to create a landscape view with 2 table views side by side, using separate table controllers.

When I select a row, I want to move that selection to the other table. Initially I wanted an array, but I couldn’t pass the array to the other controller. The array was a property of the table view controller.

I then tried to write the selection to core data, but that is crashing. To simplify, I have 2 entities in core data, Person (with name attribute and to one relationship) and SelectedPerson (with just the to one relationship to Person).

I have added the following:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    Person *person = (Person *)[fetchedResultsController objectAtIndexPath:indexPath];
    SelectedPerson *selectedPerson = [NSEntityDescription insertNewObjectForEntityForName:@"SelectedPerson"
                              inManagedObjectContext:managedObjectContext];
    [selectedPerson setValue:person forKey:@"persons"];
    [leftViewController.tableView reloadData];
    NSLog(@"Selection saved OK");

If I temporarily delete my left controller from the nib, this works fine and when I add it back, it opens with the selected persons. But with the left table view, I get the following crash log:

[49650:207] Record saved OK
[49650:207]-[Person compare:]: unrecognized selector sent to instance
[49650:207] Serious application error.  Exception was caught during Core Data change processing: -[Person compare:]: unrecognized selector sent to instance 0x3d33ef0 with userInfo (null)

***I have uploaded a sample application here link text

I’ve seen apps that use side by side tables, but I’m struggling to get this working. Any help would be greatly appreciated.

Answer 1

I figured it out – I didn’t create controllerDidChangeContent in the right view controller.

I thought because I was updating a different entity than in the `fetchedResultsController’, it wasn’t needed but it turns out it is. Probably because of the inverse relationship. Thanks for the help.