Restrict NSTextField to only allow numbers

Question

How do I restrict a NSTextfield to allow only numbers/integers? I\'ve found questions like this one, but they didn\'t help!

Answer 1

Here is the steps to create the same....

Just create the ANYCLASS(called SAMPLE) with sub classing the NSNumberFormatter ...

in .m file write the following code...

 - (BOOL)isPartialStringValid:(NSString *)partialString newEditingString:(NSString      **)newString errorDescription:(NSString **)error {
// Make sure we clear newString and error to ensure old values aren't being used
if (newString) { *newString = nil;}
if (error) {*error = nil;}

static NSCharacterSet *nonDecimalCharacters = nil;
if (nonDecimalCharacters == nil) {
    nonDecimalCharacters = [[NSCharacterSet decimalDigitCharacterSet] invertedSet] ;
}

if ([partialString length] == 0) {
    return YES; // The empty string is okay (the user might just be deleting everything and starting over)
} else if ([partialString rangeOfCharacterFromSet:nonDecimalCharacters].location != NSNotFound) {
    return NO; // Non-decimal characters aren't cool!
}

return YES;

}

Now.. in your Actual Class set the formatter to your NSTextField object like below...

NSTextField *mySampleTxtFld;

for this set the Formatter...

SAMPLE* formatter=[[SAMPLE alloc]init];// create SAMPLE FORMATTER OBJECT 

self.mySampleTxtFld.delegate=self;
[self.mySampleTxtFld setFormatter:formatter];

Your done!!!