Tableview get index out of bounds with empty array - ios

Question

I have a tableview that is filled with a fetchedresultscontroller and a searchbar. Up until now while creating the app i have only been using 7 cells and have worked great but since i started using more than 7 cells i get the error of out of bounds empty array when i touch the searchbar. but when i return it back to 7 cells it works perfect.
What could possibly be wrong?
Error:
erminating app due to uncaught exception 'NSRangeException', reason: '* -[__NSArrayM objectAtIndex:]: index 2 beyond bounds for empty array'
- (void)viewDidLoad
{
[super viewDidLoad];
self.title = #"Exercises";
id appDelegate = [[UIApplication sharedApplication] delegate];
_managedObjectContext = [appDelegate managedObjectContext];
NSError *error;
if (![[self fetchedResultsController] performFetch:&error]) {
NSLog(#"%# %#", error, [error userInfo]);
abort();
}
_searchResults = [[NSMutableArray alloc] init];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSIndexPath *selectedIndexPath = [_tableView indexPathForSelectedRow];
if (!selectedIndexPath) {
[_tableView setContentOffset:CGPointMake(0, 44) animated:NO];
}
else {
[_tableView deselectRowAtIndexPath:selectedIndexPath animated:YES];
}
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
if (self.searchDisplayController.isActive) {
[self.searchDisplayController setActive:NO animated:YES];
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#pragma mark - UITableViewDataSource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if (self.searchDisplayController.isActive) {
return 1;
}
return [[_fetchedResultsController sections] count];
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
if (self.searchDisplayController.isActive) {
return nil;
}
return [[[_fetchedResultsController sections] objectAtIndex:section] name];
}
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 22)];
view.backgroundColor = [UIColor colorWithRed:20.0/255.0 green:20.0/255.0 blue:20.0/255.0 alpha:0.8];
UILabel *sectionLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 0, 160, 22)];
sectionLabel.font = [UIFont fontWithName:#"Avenir-Book" size:16.0f];
sectionLabel.text = #"Search Results";
if (!self.searchDisplayController.isActive) {
sectionLabel.text = [[[_fetchedResultsController sections] objectAtIndex:section] name];
}
sectionLabel.backgroundColor = [UIColor clearColor];
sectionLabel.textColor = [UIColor whiteColor];
[view addSubview:sectionLabel];
return view;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (self.searchDisplayController.isActive) {
return [_searchResults count];
}
return [[[_fetchedResultsController sections] objectAtIndex:section] numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"exerciseCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
[self stampCell:cell atIndexPath:indexPath];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
#pragma mark - Cell
- (void)stampCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
if ([cell.reuseIdentifier isEqualToString:#"exerciseCell"]) {
UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 2, 150, 22)];
textLabel.tag = kExerciseCellTextLabel;
textLabel.font = [UIFont systemFontOfSize:18.0];
textLabel.textColor = [UIColor blackColor];
textLabel.highlightedTextColor = [UIColor whiteColor];
textLabel.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:textLabel];
UILabel *detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 24, 150, 18)];
detailTextLabel.tag = kExerciseCellDetailTextLabel;
detailTextLabel.font = [UIFont systemFontOfSize:14.0];
detailTextLabel.textColor = [UIColor colorWithRed:128.0/255.0 green:128.0/255.0 blue:128.0/255.0 alpha:1.0];
detailTextLabel.highlightedTextColor = [UIColor colorWithRed:127.0/255.0 green:127.0/255.0 blue:127.0/255.0 alpha:1.0];
detailTextLabel.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:detailTextLabel];
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
if ([cell.reuseIdentifier isEqualToString:#"exerciseCell"]) {
UILabel *textLabel = (UILabel *)[cell.contentView viewWithTag:kExerciseCellTextLabel];
UILabel *detailTextLabel = (UILabel *)[cell.contentView viewWithTag:kExerciseCellDetailTextLabel];
Exercise *exercise;
if (self.searchDisplayController.isActive) {
exercise = [_searchResults objectAtIndex:indexPath.row];
}
else {
exercise = [_fetchedResultsController objectAtIndexPath:indexPath];
}
textLabel.text = [exercise valueForKey:kExerciseName];
detailTextLabel.text = [NSString stringWithFormat:#"%# - %#", [[exercise valueForKey:kExerciseEType] valueForKey:kExerciseTypeName], [[exercise valueForKey:kExerciseGear] valueForKey:kGearName]];
cell.selectionStyle = UITableViewCellSelectionStyleGray;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
}
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self performSegueWithIdentifier:#"exerciseDetail" sender:self];
}
#pragma mark - UISearchBarDelegate
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[_searchResults removeAllObjects];
if (searchString.length > 0) {
for (Exercise *exercise in [_fetchedResultsController fetchedObjects]) {
NSRange range = [[exercise valueForKey:kExerciseName] rangeOfString:searchString options:NSCaseInsensitiveSearch];
if (range.location == 0) {
[_searchResults addObject:exercise];
}
}
}
return YES;
}
- (BOOL)searchBarShouldBeginEditing:(UISearchBar*)searchBar {
[super setPan];
return YES;
}
- (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar
{
[super setPan];
return YES;
}
#pragma mark - NSFetchedResultsControllerDelegate
- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController) {
return _fetchedResultsController;
}
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:kExercise inManagedObjectContext:_managedObjectContext];
[request setEntity:entity];
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:kExerciseName ascending:YES];
[request setSortDescriptors:[NSArray arrayWithObject:sort]];
NSFetchedResultsController *fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:_managedObjectContext sectionNameKeyPath:kExerciseFirstLetter cacheName:#"ExerciseList"];
[self setFetchedResultsController:fetchedResultsController];
[_fetchedResultsController setDelegate:self];
return _fetchedResultsController;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:#[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:#[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView endUpdates];
}
#end

Answer 1

It shows like some of array remains empty..the better way to check it
-Put NSLog statement after array element and run it..IT shows which array remains empty.
By doing so if your problem doesn't get solved..please let me know..so,i can help you further..

Answer 2

Where do you see the crash - when showing just search results or when showing the entire list?
If its just search results, then your _searchResults does not have more than 7 records.
If it is when you are showing all results, then check the number of records in each value of _fetchedResultsController.sections. Looks like they don't have more than 7 records.

Answer 3

Hi i guess ur removing all elements from _searchResults may be due to this the app is crashing.please check this once.
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[_searchResults removeAllObjects];