Problem with adding a new row and populating it - ios

Question

I am trying to add a new row to my custom cell with an NSMutablearray from another viewcontroller but I am getting an error when a new row is added. itemsTableView is visible in photoCaptureView which is the view for photoCaptureViewController. So when ScannerModalViewController (which is being called also in photoCaptureViewController) is called and capture the item/data and once it is dismissed scannedBarcode is called to add a new row to my custom cell and populate it I'm getting this error.
I am getting a warning and an error. The warning is
Warning once only: UITableView was told to layout its visible cells and other contents without
being in the view hierarchy (the table view or one of its superviews has not been added to a
window). This may cause bugs by forcing views inside the table view to load and perform layout
without accurate information (e.g. table view bounds, trait collection, layout margins, safe
area insets, etc), and will also cause unnecessary performance overhead due to extra layout
passes. Make a symbolic breakpoint at UITableViewAlertForLayoutOutsideViewHierarchy to catch
this in the debugger and see what caused this to occur, so you can avoid this action altogether
if possible, or defer it until the table view has been added to a window. Table view:
<UITableView: 0x1038a9c00; frame = (10 70; 398 794); clipsToBounds = YES; gestureRecognizers =
<NSArray: 0x28165f0c0>; layer = <CALayer: 0x2818ebb20>; contentOffset: {0, 0}; contentSize:
{398, 60}; adjustedContentInset: {0, 0, 0, 0}; dataSource: <PhotoCaptureViewController: 0x10364a880>>
error is
Invalid update: invalid number of rows in section 0. The number of rows contained in an existing
section after the update (3) must be equal to the number of rows contained in that section
before the update (1), plus or minus the number of rows inserted or deleted from that section
(1 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section
(0 moved in, 0 moved out).
My code is photoCaptureViewController.h
#interface PhotoCaptureViewController : UIViewController <UITableViewDataSource, UITableViewDelegate, ScannerModalViewControllerDelegate> {
PhotoCaptureView* photoCaptureView;
NSMutableArray* barcodeItems;
ScannerModalViewController* scannerModalViewController;
}
-(void) scanBarcode;
-(void) scannedBarcode:(NSString *) barcode;
#end
photoCaptureViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
[photoCaptureView.itemsTableView registerNib:[UINib nibWithNibName:#"BarcodeItemsTableViewCell" bundle:nil] forCellReuseIdentifier:#"BarcodeItemsCell"];
photoCaptureView.itemsTableView.rowHeight = 60;
photoCaptureView.itemsTableView.dataSource = self;
photoCaptureView.itemsTableView.delegate = self;
[photoCaptureView.itemsTableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
}
#pragma mark scannerModalViewController Methods
-(void) scanBarcode {
NSLog(#"[%#] Scan Barcode Requested", self.class);
scannerModalViewController = [[ScannerModalViewController alloc] init];
scannerModalViewController.delegate = self;
scannerModalViewController.modalPresentationStyle = UIModalPresentationFullScreen;
[self presentViewController:scannerModalViewController animated:YES completion:nil];
}
-(void) scannedBarcode:(NSMutableArray *) barcodes {
barcodeItems = [[NSMutableArray alloc] init];
[barcodeItems addObjectsFromArray:barcodes];
[barcodeItems addObject:#"test"];
[barcodeItems addObject:#"test1"];
NSLog(#"%#", barcodes);
NSLog(#"%#", barcodeItems);
NSIndexPath* indexPath = [NSIndexPath indexPathForRow:barcodeItems.count-1 inSection:0];
[photoCaptureView.itemsTableView beginUpdates];
[photoCaptureView.itemsTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[photoCaptureView.itemsTableView endUpdates];
}
#pragma mark UITableViewDataSource methods
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return barcodeItems.count + 1;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"Cell Initialized");
static NSString *cellIdentifier = #"BarcodeItemsCell";
BarcodeItemsTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
if (cell == nil) {
cell = [[BarcodeItemsTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
// Configure the cell...
cell.barcodeLabel.text = [barcodeItems objectAtIndex:indexPath.row];
UIImage *btnImage = [UIImage imageNamed:#"barcodeIcon"];
[cell.leftButton setImage:btnImage forState:UIControlStateNormal];
NSLog(#"Cell Populated");
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
return true;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
[barcodeItems removeObjectAtIndex:indexPath.row];
[photoCaptureView.itemsTableView beginUpdates];
[photoCaptureView.itemsTableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[photoCaptureView.itemsTableView endUpdates];
}
}
#end

Answer 1

If you insert the items with insertRowsAtIndexPaths you have to specify all paths.
And beginUpdates /endUpdates` has no effect for a single insert/delete/move operation.
-(void) scannedBarcode:(NSMutableArray *) barcodes {
barcodeItems = [[NSMutableArray alloc] init];
[barcodeItems addObjectsFromArray:barcodes];
[barcodeItems addObject:#"test"];
[barcodeItems addObject:#"test1"];
NSLog(#"%#", barcodes);
NSLog(#"%#", barcodeItems);
NSMutableArray<NSIndexPath *>* indexPaths = [[NSMutableArray alloc] init];
for (i = 0; i < barcodeItems.count; i++) {
[indexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
}
[photoCaptureView.itemsTableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationAutomatic];
}
And numberOfRowsInSection must return
return barcodeItems.count;