NSDecimalNumberOverflowException - Issue

Question

I have UITextField whose owner is the delegate for the textfield. I have declared the UITextField as below:

 self.thresholdValueTextField.delegate = self;

NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[numberFormatter setMaximumFractionDigits:2];
[numberFormatter setMinimumFractionDigits:2];

self.thresholdValueTextField.text = [numberFormatter stringFromNumber:[NSNumber numberWithInt:0]];

When the user keeps pressing on the back button even the string is $0.00, my app crashes due to the following error:

*** Terminating app due to uncaught exception 'NSDecimalNumberOverflowException', reason: 'NSDecimalNumber overflow exception'

Given below is the code that handles textField: shouldChangeCharactersInRange: delegate method:

- (BOOL)textField:(UITextField*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string
{
  NSInteger MAX_DIGITS = 10; // $999,999,999.99

  NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
  [numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
  [numberFormatter setMaximumFractionDigits:2];
  [numberFormatter setMinimumFractionDigits:2];

  NSString *stringMaybeChanged = [NSString stringWithString:string];
  if (stringMaybeChanged.length > 1)
  {
     NSMutableString *stringPasted = [NSMutableString stringWithString:stringMaybeChanged];

     [stringPasted replaceOccurrencesOfString:numberFormatter.currencySymbol
                                  withString:@""
                                     options:NSLiteralSearch
                                       range:NSMakeRange(0, [stringPasted length])];

     [stringPasted replaceOccurrencesOfString:numberFormatter.groupingSeparator
                                  withString:@""
                                     options:NSLiteralSearch
                                       range:NSMakeRange(0, [stringPasted length])];

     NSDecimalNumber *numberPasted = [NSDecimalNumber decimalNumberWithString:stringPasted];
     stringMaybeChanged = [numberFormatter stringFromNumber:numberPasted];
  }

   UITextRange *selectedRange = [textField selectedTextRange];
   UITextPosition *start = textField.beginningOfDocument;
   NSInteger cursorOffset = [textField offsetFromPosition:start toPosition:selectedRange.start];
   NSMutableString *textFieldTextStr = [NSMutableString stringWithString:textField.text];
   NSUInteger textFieldTextStrLength = textFieldTextStr.length;

   [textFieldTextStr replaceCharactersInRange:range withString:stringMaybeChanged];

   [textFieldTextStr replaceOccurrencesOfString:numberFormatter.currencySymbol
                                  withString:@""
                                     options:NSLiteralSearch
                                       range:NSMakeRange(0, [textFieldTextStr length])];

   [textFieldTextStr replaceOccurrencesOfString:numberFormatter.groupingSeparator
                                  withString:@""
                                     options:NSLiteralSearch
                                       range:NSMakeRange(0, [textFieldTextStr length])];

   [textFieldTextStr replaceOccurrencesOfString:numberFormatter.decimalSeparator
                                  withString:@""
                                     options:NSLiteralSearch
                                       range:NSMakeRange(0, [textFieldTextStr length])];

   if (textFieldTextStr.length <= MAX_DIGITS)
   {
    NSDecimalNumber *textFieldTextNum = [NSDecimalNumber decimalNumberWithString:textFieldTextStr];
    NSDecimalNumber *divideByNum = [[[NSDecimalNumber alloc] initWithInt:10] decimalNumberByRaisingToPower:numberFormatter.maximumFractionDigits];
    NSDecimalNumber *textFieldTextNewNum = [textFieldTextNum decimalNumberByDividingBy:divideByNum];
    NSString *textFieldTextNewStr = [numberFormatter stringFromNumber:textFieldTextNewNum];

    textField.text = textFieldTextNewStr;

    if (cursorOffset != textFieldTextStrLength)
    {
        NSInteger lengthDelta = textFieldTextNewStr.length - textFieldTextStrLength;
        NSInteger newCursorOffset = MAX(0, MIN(textFieldTextNewStr.length, cursorOffset + lengthDelta));
        UITextPosition* newPosition = [textField positionFromPosition:textField.beginningOfDocument offset:newCursorOffset];
        UITextRange* newRange = [textField textRangeFromPosition:newPosition toPosition:newPosition];
        [textField setSelectedTextRange:newRange];
     }
   }

  return NO;
}

May I know what's causing this error?

Step through your code with the debugger. See which statement is raising the exception. Then see what the string values are that you are trying to use. — user3821934

Siddharthan Asokan Siddharthan Asokan · Accepted Answer · 2015-05-20T03:24:13

The issue was with the DecimalNumberByDividingBy for [NSDecimalNumber Zero] and NaN occurence.

Updating the code for DecimalNumberByDivindingBy solved it

 NSDecimalNumber *textFieldTextNewNum;
 if ([textFieldTextNum compare:[NSDecimalNumber zero]] == NSOrderedSame || [[NSDecimalNumber notANumber] isEqualToNumber:textFieldTextNum]) {
        textFieldTextNewNum = [NSDecimalNumber zero];
 }else{
        textFieldTextNewNum = [textFieldTextNum decimalNumberByDividingBy:divideByNum];
 }

NSDecimalNumberOverflowException - Issue

1 Answers