SFSafariViewController blank in iOS 11/Xcode 9.0

Question

I have a SFSafariViewController opening at the click of a button inside a UIActionSheet. It has been working fine and is still working fine on all the versions of iOS except iOS 11. Is there something they have changed regarding the SFSafariViewController in iOS 11 or in Xcode 9.0 that might have caused this issue?

UPDATE - So it seems like its Xcode 9.0 that is causing this issue. I have tried running it on different iOS versions and all of them seem to be giving this issue. It used to work fine when I ran it using Xcode 8.3.3, something I don't have anymore :(

Here's the code -

- (void)presentWebView:(NSString *)url {
url = [url stringByReplacingOccurrencesOfString:@" " withString:@"+"];
url = [url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *URL = [NSURL URLWithString:url];

if (URL) {
    if ([SFSafariViewController class] != nil) {
        SFSafariViewController *sfvc = [[SFSafariViewController alloc] initWithURL:URL];
        sfvc.delegate = self;
        [self.tabBarController presentViewController:sfvc animated:YES completion:nil];
    } else {
        if (![[UIApplication sharedApplication] openURL:URL]) {
            NSLog(@"%@%@",@"Failed to open url:",[url description]);
        }
    }
} else {
    // will have a nice alert displaying soon.
}

}

Answer 1

I've managed to fix this in my code. I hope this helps anyone else with a similar problem.

I had the exact same problem as described here. I tried everything above and unfortunately nothing worked.

In my app there were different windows. The fix was to ensure the window that would show SFSafariViewController was 'key' before presenting it. For example:

class MyViewController: UIViewcontroller {
    func showSafariViewController() {
        // imagine we have 2 windows, one for 'normal' content (key window) and one for 'other' content. lets say we're showing the 'other' content window, and have hidden the 'normal' window. you can see the 'other' content window in the app, but it won't be the key window!
        let window = // get the 'other' content window

        // make sure we make it the key window before presenting safari
        window.makeKey()

        // now present safari and celebrate victory by triumphantly slurping on your hot black coffee
        let mySafariViewController = SFSafariViewController(...)
        self.present(mySafariViewController ...)
    }
}

I suspect Apple are searching for a SFSafariViewController instance in the window UIApplication.shared.keyWindow. Perhaps they're adding a child view from somewhere else. In the documentation it states The user's activity and interaction with SFSafariViewController are not visible to your app, so perhaps it's the bug is something related to an added level of security https://developer.apple.com/documentation/safariservices/sfsafariviewcontroller