Question

I have some UITextViews. Where User will enter data and this data will be submitted to database using web service.The database shows error with special characters like ‘&’. So I want to block user when he/she tries to submit data with this special characters or there should a message on submitting the data’ I mean How to validate that textview? If somebody knows about it please help me. Thanx a lot.

Answer 1

First way, mentioned all accepted charecters like below sample code and if found out of range characters put message to display.

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{
    NSCharacterSet * set = [[NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789"] invertedSet];
    if ([textField.text rangeOfCharacterFromSet:set].location != NSNotFound) 
    {
        NSLog(@"This string contains illegal characters");
        return FALSE;
    }
    return TRUE;
}

Or, go with Regular Expression and do the same thing in another way…

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{
    if ([textField.text isMatchedByRegex:@"[^a-zA-Z0-9]"]) 
    {
        NSLog(@"This string contains illegal characters");
        return FALSE;
    }
    return TRUE;
}