I can’t figure out how come the row count is correct but the uitableview won’t load the row contents the NSLog shows carresults=(null), but the row count is correct, on the simulator if I relaunch, the carresults get filled. It seems like I’m missing my first fetchedResultsController teh first time through, but how can it get the row count if it doesn’t know what’ there?
Help!! any Ideas? Thanks, Mike
The titleForHeaderInSection works fine, brings back the correct titles:
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
return [[[fetchedResultsController1 sections] objectAtIndex:section] name];
}
This brings back the correct row count:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController1 sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
This does not populate the cells until a rebuild on simulator, never populates the iPhone.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *FirstViewIdentifier = @"FirstViewIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:FirstViewIdentifier];
if (cell == nil) {
[[NSBundle mainBundle] loadNibNamed:@"Cell" owner:self options:nil];
cell = firstviewCell;
self.firstviewCell = nil;
}
Cars *carresults = (Cars *)[fetchedResultsController1 objectAtIndexPath:indexPath];
NSLog(@"carresults %@", carresults.make);
EDIT: Here is the FRC:
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[[[UIApplication sharedApplication] delegate] managedObjectContext] sectionNameKeyPath:@"key" cacheName:@"Root1"];
self.fetchedResultsController = aFetchedResultsController;
fetchedResultsController.delegate = self;
Since you haven’t provided any debug info I can only guess as to what’s wrong, so I’ll ask you some questions. Does it in fact instantiate the firstviewCell property with the nib. If the cell is not connected to the firstviewCell property of the File Owner (in the nib) it won’t work. Otherwise if the fetchedResultsController doesn’t have anything in it you’ll get an error if you try to access the data. If the nslog fires then you probably didn’t get an error, which means that your Cars objects are being fetched theres just nothing in them. to see whats in the fetchedResultsController call NSLog(@”Fetched Objects: %@”,[[fetchedResultsController fetchedObjects] description]); Keep in mind though, that fetchedObjects is only updated when you call performFetch. Since you say carresults gets filled when you restart the app it may be possible that you need to call saveContext for the results to get loaded. The only reason for this is if you create the data at runtime, before the table view gets loaded. Otherwise I would assume you have the table view set as the fetched results controller’s delegate so that it gets informed of any changes and responds appropriately. The app delegate usually does this on applicationWillResign active or applicationWillTerminate (applicationWillTerminate doesn’t seem to get called by iOS4 during normal closing).The only other thing I could think of is that maybe your SectionInfo object might contain the wrong information, try debugging that too.
Good Luck,
Rich
Edit: I appologize, the save context method is a method added to your appdelegate when you create an app based on core data. a good way to make a core data stack is to wrap it in an NSObject, it can be useful to make it a singleton ,unless of course you need concurrency in which case it gets really complicated. This is the implementation including the save context function:
// CoreDataStack.m