Specific URL Validation

Question

I saw a lot of duplicates of this question but finally found nothing suitable for me. I need to validate my url in my app like in Safari App in iOS (7 for example).

For example : I need those strings to be VALIDATED: http://apple.com ; http://www.apple.com And those to be NOT VALIDATED: http://apple.apple ; http://apple ; http://www.........something

I'm trying to do like this:

    #define stringRegex @"^(http://|https://|http://www.|https://www.)[a-z0-9-.]+(aero|asia|biz|cat|com|coop|edu|gov|info|int|jobs|mil|mobi|museum|name|net|org|pro|tel|travel|ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|ax|az|ba|bb|bd|be|bf|bg|bh|bi|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cu|cv|cx|cy|cz|cz|de|dj|dk|dm|do|dz|ec|ee|eg|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|me|mg|mh|mk|ml|mn|mn|mo|mp|mr|ms|mt|mu|mv|mw|mx|my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|nom|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|pt|pw|py|qa|re|ra|rs|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tl|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw|arpa)([/?].*)?$"

...

         NSString *stringToCheck = searchBar.text;
         if ([stringToCheck rangeOfString:@"https://"].location != NSNotFound) {
                 stringToCheck = [stringToCheck stringByReplacingOccurrencesOfString:@"https://"
                                                                                 withString:@"http://"];
         }
         if ([stringToCheck rangeOfString:@"http://"].location == NSNotFound) {
                 stringToCheck = [NSString stringWithFormat:@"http://%@",stringToCheck];
         }

         NSString * urlAddress = stringToCheck;
         NSError *error = NULL;
         NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:stringRegex options:NSRegularExpressionCaseInsensitive error:&error];
         NSTextCheckingResult *match = [regex firstMatchInString:urlAddress
                                                                 options:0 range:NSMakeRange(0, [urlAddress length])];
         if (match) {
                         NSLog(@"Url is valid");
         }
                 else {
                         NSLog(@"Url isn't valid");
}

Finally it's working in 99% of cases, BUT sometimes validates invalid strings. I don't know why. For example:

http://test - valid ; http://thkl - invalid (it's right)

So that's the problem I'm trying to solve.

Answer 1

Your regex pattern doesn't ensure that there is a period (dot) before the last match is made. So http://test is matching:

1. http://
2. te
3. st

And you need to update your pattern to ensure that there are dots in the correct place. Remember to escape the dot is it isn't a wildcard.