Error on tableview with search functionality - uitableview

Question

I have a view where I programmatically create Search functionality. The App works fine in iOS 6 but crashes on devices running iOS 7. I get an error stating "Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'A nil string was passed for sorting.'
*** First throw call stack:".Is there anything wrong that I'm doing? Here's the code that executes in the viewDidLoad method:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
{
// Get the DBAccess object;
DBAccess *dbAccess = [[DBAccess alloc] init];
// Get array of products that do not have a barcode
productsWithNoBarcodeArray = [dbAccess getUserProductsWithNoBarcode];
// Close the database because we are finished with it
[dbAccess closeDatabase];
}
NSLog(#"Number of products with no barcodes is: %d",[productsWithNoBarcodeArray count]);
/***************************************Implementing Tableview Sections and Index*****************************/
self.retailers = [NSMutableArray arrayWithCapacity:1];
UILocalizedIndexedCollation *indexedCollation = [UILocalizedIndexedCollation currentCollation];
//Iterate over the retailers, populating their section number
for (Product *theRetailer in productsWithNoBarcodeArray)
{
NSInteger section = [indexedCollation sectionForObject:theRetailer collationStringSelector:#selector(sProductSearch)];
theRetailer.section = section;
}
//Get the count of the number of sections
NSInteger sectionCount = [[indexedCollation sectionTitles] count];
//Create an array to hold subarrays for the various sections
NSMutableArray *sectionsArray = [NSMutableArray arrayWithCapacity:sectionCount];
//Iterate over each section, creating each subarray
for (int i=0; i<= sectionCount; i++)
{
NSMutableArray *singleSectionArray = [NSMutableArray arrayWithCapacity:1];
[sectionsArray addObject:singleSectionArray];
}
//Iterate over the retailers, putting each retailer into the correct subarray
for (Product *theRetailer in productsWithNoBarcodeArray)
{
[(NSMutableArray *)[sectionsArray objectAtIndex:theRetailer.section] addObject:theRetailer];
}
//Iterate over each section array to sort items in the section
for (NSMutableArray *singleSectionArray in sectionsArray)
{
//Use the UILocalizedIndexedCollation sortedArrayFromArray: method to sort each array
NSArray *sortedSection = [indexedCollation sortedArrayFromArray:singleSectionArray collationStringSelector:#selector(sProductSearch)];
NSSortDescriptor * descriptor = [[NSSortDescriptor alloc] initWithKey:#"sItemDescription" ascending:NO]; // 1
NSArray *sortedByNameArray = [sortedSection sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]];
// [self.retailers addObject:sortedSection];
[self.retailers addObject:sortedByNameArray];
}
NSLog(#"The count on manualTap retailers is: %d",[self.retailers count]);
/***************************************END - Implementing Tableview Sections and Index*****************************/
/*********************Programmatically create a search bar***********************/
self.searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0.0f,0.0f, 320.0f, 44.0f)];
self.shoppingListTable.tableHeaderView = self.searchBar;
//Create and configure the search controller
self.searchController = [[UISearchDisplayController alloc]initWithSearchBar:self.searchBar contentsController:self];
self.searchController.searchResultsDataSource = self;
self.searchController.searchResultsDelegate = self;
bfiltered = NO;
searchBar.keyboardType = UIKeyboardTypeNumbersAndPunctuation; //UIKeyboardTypeNumberPad;
}

Answer 1

I happened into this when the collection that is being sorted by the UILocalizedIndexedCollation had multiple objects that returned nil when the selector was invoked on them.
In your code, this was the line that was breaking for me:
NSArray *sortedSection = [indexedCollation sortedArrayFromArray:singleSectionArray collationStringSelector:#selector(sProductSearch)];
My solution was to make sure that any objects that returned nil when the selector was invoked didn't get added to the array sent to the UILocalizedIndexedCollation.
For example, in your code, I did something like this:
for (Product *theRetailer in productsWithNoBarcodeArray)
{
if ([theRetailer valueForKey:#"sProductSearch"] != nil)
{
[(NSMutableArray *)[sectionsArray objectAtIndex:theRetailer.section] addObject:theRetailer];
}
}