Navigation-based Core Data Application Template Reposted

Based on some feedback to an earlier post, I was able to fix another bug in my version of Apple's Navigation-based Core Data Application Xcode template. It was an off-by-one error caused by using a >= when I should have used just a >.

New version of delegate methods follow:

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView beginUpdates];
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView endUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {
    switch(type) {
        case NSFetchedResultsChangeInsert:
            [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeDelete:
            [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeUpdate: {
            NSString *sectionKeyPath = [controller sectionNameKeyPath];
            if (sectionKeyPath == nil)
                break;
            NSManagedObject *changedObject = [controller objectAtIndexPath:indexPath];
            NSArray *keyParts = [sectionKeyPath componentsSeparatedByString:@"."];
            id currentKeyValue = [changedObject valueForKeyPath:sectionKeyPath];
            for (int i = 0; i < [keyParts count] - 1; i++) {
                NSString *onePart = [keyParts objectAtIndex:i];
                changedObject = [changedObject valueForKey:onePart];
            }
            sectionKeyPath = [keyParts lastObject];
            NSDictionary *committedValues = [changedObject committedValuesForKeys:nil];
            
            if ([[committedValues valueForKeyPath:sectionKeyPath] isEqual:currentKeyValue])
                break;
            
            NSUInteger tableSectionCount = [self.tableView numberOfSections];
            NSUInteger frcSectionCount = [[controller sections] count];
            if (tableSectionCount != frcSectionCount) {
                // Need to insert a section
                NSArray *sections = controller.sections;
                NSInteger newSectionLocation = -1;
                for (id oneSection in sections) {
                    NSString *sectionName = [oneSection name];
                    if ([currentKeyValue isEqual:sectionName]) {
                        newSectionLocation = [sections indexOfObject:oneSection];
                        break;
                    }
                }
                if (newSectionLocation == -1)
                    return; // uh oh
                
                if (!((newSectionLocation == 0) && (tableSectionCount == 1) && ([self.tableView numberOfRowsInSection:0] == 0)))
                    [self.tableView insertSections:[NSIndexSet indexSetWithIndex:newSectionLocation] withRowAnimation:UITableViewRowAnimationFade];
                NSUInteger indices[2] = {newSectionLocation, 0};
                newIndexPath = [[[NSIndexPath alloc] initWithIndexes:indices length:2] autorelease];
            }
        }
        case NSFetchedResultsChangeMove:
            if (newIndexPath != nil) {
                
                NSUInteger tableSectionCount = [self.tableView numberOfSections];
                NSUInteger frcSectionCount = [[controller sections] count];
                if (frcSectionCount > tableSectionCount) 
                    [self.tableView insertSections:[NSIndexSet indexSetWithIndex:[newIndexPath section]] withRowAnimation:UITableViewRowAnimationNone];
                else if (frcSectionCount < tableSectionCount && tableSectionCount > 1)
                    [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:[indexPath section]] withRowAnimation:UITableViewRowAnimationNone];
                
                
                [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
                [self.tableView insertRowsAtIndexPaths: [NSArray arrayWithObject:newIndexPath]
                                      withRowAnimation: UITableViewRowAnimationRight];
                
            }
            else {
                [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:[indexPath section]] withRowAnimation:UITableViewRowAnimationFade];
            }
            break;
        default:
            break;
    }
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
    switch(type) {
            
        case NSFetchedResultsChangeInsert:
            if (!((sectionIndex == 0) && ([self.tableView numberOfSections] == 1)))
                [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeDelete:
            if (!((sectionIndex == 0) && ([self.tableView numberOfSections] == 1) ))
                [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
        case NSFetchedResultsChangeMove:
            break;
        case NSFetchedResultsChangeUpdate: 
            break;
        default:
            break;
    }
}

Posted in: Core Data,Sample Code,Xcode Project