ios - swift spritekit Facebook share button

Question

Hey there my app is almost ready for release but i want to add a Facebook share button. The thing is i have no idea how the communication between the scene and the viewcontroler works. i did my research but only found code in obj-c like this one

- (void)lkFaceBookShare {
    NSString *serviceType = SLServiceTypeFacebook;
    if (![SLComposeViewController isAvailableForServiceType:serviceType])
    {
        [self showUnavailableAlertForServiceType:serviceType];
    }
    else
    {
        SLComposeViewController *composeViewController = [SLComposeViewController composeViewControllerForServiceType:serviceType];
        UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
        CGRect rect = [keyWindow bounds];
        UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, 0.5f);
        [self.view drawViewHierarchyInRect:rect afterScreenUpdates:YES];
        UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        [composeViewController addImage:viewImage];
        NSString *initalTextString = [NSString stringWithFormat:@"Let's join together in the form of underground catch word go along with me!! Link: https://itunes.apple.com/us/app/uoi-hinh-bat-chu-gioi-duoi/id907330926?ls=1&mt=8"];
        [composeViewController setInitialText:initalTextString];
        UIViewController *vc = self.view.window.rootViewController;
        [vc presentViewController:composeViewController animated:YES completion:nil];
    }
}

- (void)showUnavailableAlertForServiceType:(NSString *)serviceType
{
    NSString *serviceName = @"";

    if (serviceType == SLServiceTypeFacebook)
    {
        serviceName = @"Facebook";
    }
    else if (serviceType == SLServiceTypeSinaWeibo)
    {
        serviceName = @"Sina Weibo";
    }
    else if (serviceType == SLServiceTypeTwitter)
    {
        serviceName = @"Twitter";
    }

    UIAlertView *alertView = [[UIAlertView alloc]
                              initWithTitle:@"Account"
                              message:[NSString stringWithFormat:@"Please go to the device settings and add a %@ account in order to share through that service", serviceName]
                              delegate:nil
                              cancelButtonTitle:@"Dismiss"
                              otherButtonTitles:nil];
    [alertView show];
}

my experience and knowledge is too low to port this too swift so i need some help with this D:

Thanks

Answer 1

This is some code I did for twitter a while ago which still works in swift. I show you how to convert it to Facebook below. Put this your viewController:

func showTweetSheet() {
    let tweetSheet = SLComposeViewController(forServiceType: SLServiceTypeTwitter)
    tweetSheet.completionHandler = {
        result in
        switch result {
        case SLComposeViewControllerResult.Cancelled:
            //Add code to deal with it being cancelled
            break

        case SLComposeViewControllerResult.Done:
            //Add code here to deal with it being completed
            //Remember that dimissing the view is done for you, and sending the tweet to social media is automatic too. You could use this to give in game rewards?
            break
        }
    }

    tweetSheet.setInitialText("Test Twitter") //The default text in the tweet 
    tweetSheet.addImage(UIImage(named: "TestImage.png")) //Add an image if you like?
    tweetSheet.addURL(NSURL(string: "http://twitter.com")) //A url which takes you into safari if tapped on

    self.presentViewController(tweetSheet, animated: false, completion: {
        //Optional completion statement
        })
}

To convert it to Facebook, simply swap SLServiceTypeTwitter to SLServiceTypeFacebook and rename the variables for readability. If you want to call this method from the SKScene, you have to somehow alert the viewController that you want it to call a method.

My preferred way is to use NSNotificationCenter so that I post an alert from the scene and it is received by the viewController so that it fires a method. This is also incredibly easy to setup. In the scene, you need to put this line of code wherever you want to call the Facebook popup:

NSNotificationCenter.defaultCenter().postNotificationName("WhateverYouWantToCallTheNotification", object: nil)

This sends out a notification with a name. Now, in the viewController you need to subscribe to this alert by putting the following code in either viewDidLoad, viewDidAppear or something similar.

NSNotificationCenter.defaultCenter().addObserver(self, selector: "ThisIsTheMethodName", name: "WhateverYouCalledTheAlertInTheOtherLineOfCode", object: nil)

Now the scene will communicate with the viewController and you will be able to show the Facebook sheet. Remember to replace my strings with ones relative to your project. Hope this helps - sorry it was such a long answer!