NSNumberFormatter not allowing decimal input

Question

If I enter a decimal point '.' into my UITextField, the number formatter called does not recognise the decimal point and continues as if the decimal point has not been entered. I.e If I entered 200.9, the decimal point would not show up in the textfield and the text of the textfield would be 2009.

I want to limit the number of digits after the decimal point to 2 as I believe I am doing below. Please can you tell me what I am doing to cause this?

- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    BOOL isDeleting = [textField.text substringWithRange:range].length > string.length;
    int index = [textFields indexOfObject:textField];
    NSString *input;

    if (isDeleting == NO)
        input = [textField.text stringByAppendingString:string];
    else {
        NSMutableString *str = [textField.text mutableCopy];
        [str deleteCharactersInRange:range];
        input = [[str copy] autorelease];
        [str release];
    }

    if ([input isEqualToString:@"£"] || ([input isEqualToString:@""] && index != 1)) {
        [textField setText:@"£"];
    }
    else {
        if (index != 1)
            [textField setText:[self numberFormattedString:input]];
        else 
            [textField setText:input];
    }

    return NO;
}
- (NSString *) numberFormattedString:(NSString *)str {
    str = [str stringByReplacingOccurrencesOfString:@"£" withString:@""];
    str = [str stringByReplacingOccurrencesOfString:@"," withString:@""];
    NSNumberFormatter *formatter = [[[NSNumberFormatter alloc] init] autorelease];
    [formatter setNumberStyle:NSNumberFormatterCurrencyStyle];
    NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en-UK"];
    [formatter setLocale:locale];
    [locale release];
    [formatter setAllowsFloats:YES];
    [formatter setMaximumFractionDigits:3];
    [formatter setMinimumFractionDigits:0];
    [formatter setDecimalSeparator:@"."];
    return [formatter stringFromNumber:[NSNumber numberWithFloat:[str floatValue]]];
}

TIA.

Answer 1

Let's say you enter the number 100 and then a decimal point. When numberFormattedString is called with the string £100., it's going to get rid of the £, and str will contain the string 100. which [str floatValue] converts to the float value 100, and finally your number formatter spits it back out as the string £100 without any decimal point. So basically [str floatValue] is killing your decimal point.

One solution is to check for when you get the decimal point as your replacement string in the text field delegate method, and skip calling numberFormattedString in that case. Then when the user enters the next digit, you can carry on calling numberFormattedString, and the conversion should happen correctly. You'll just have to make sure that the user can only enter one decimal point.

EDIT: I just realized that my suggested solution still won't work if you enter a 0 after the decimal point (e.g. 100.0), but I'm sure there is a minor tweak that you can figure out to solve that.