How to check validity of URL in Swift?

Question

Trying to make an app launch the default browser to a URL, but only if the URL entered is valid, otherwise it displays a message saying the URL is invalid.

How would

Answer 1

2020, I was tasked on fixing a bug of a method for underlining string links within a string. Most of the answers here don't work properly (try: aaa.com.bd or aaa.bd) These links should be valid. And then I stumbled upon the regex string for this.

Ref: https://urlregex.com/

So based on that regex

"((?:http|https)://)?(?:www\\.)?[\\w\\d\\-_]+\\.\\w{2,3}(\\.\\w{2})?(/(?<=/)(?:[\\w\\d\\-./_]+)?)?"

We can write a function.

SWIFT 5.x:

extension String {
    var validURL: Bool {
        get {
            let regEx = "((?:http|https)://)?(?:www\\.)?[\\w\\d\\-_]+\\.\\w{2,3}(\\.\\w{2})?(/(?<=/)(?:[\\w\\d\\-./_]+)?)?"
            let predicate = NSPredicate(format: "SELF MATCHES %@", argumentArray: [regEx])
            return predicate.evaluate(with: self)
        }
    }
}

OBJECTIVE-C (write this however you want, category or not).

- (BOOL)stringIsValidURL:(NSString *)string
{
    NSString *regEx = @"((?:http|https)://)?(?:www\\.)?[\\w\\d\\-_]+\\.\\w{2,3}(\\.\\w{2})?(/(?<=/)(?:[\\w\\d\\-./_]+)?)?";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@" argumentArray:@[regEx]];
    return [predicate evaluateWithObject:string];
}