Question

I am trying to build a homebrew web brower to get more proficient at Cocoa. I need a good way to validate whether the user has entered a valid URL. I have tried some regular expressions but NSString has some interesting quirks and doesn’t like some of the back-quoting that most regular expressions I’ve seen use.

Answer 1

You could start with the + (id)URLWithString:(NSString *)URLString method of NSURL, which returns nil if the string is malformed.

If you need further validation, you can use the baseURL, host, parameterString, path, etc methods to give you particular components of the URL, which you can then evaluate in whatever way you see fit.