Apple Music detect is member - objective-c

Question

In iOS 9.3 Apple release new APIs. Now developers can see if a user is currently a member of Apple Music. I'm trying to understand how it works.
My code -only first time- asks the user whether to access the music library but I don't understand how to determine in what ways you can detect if user is a member and open Apple Music to join it. These actions in Shazam works really great. How can I do something like that?
Thanks in advance!
[SKCloudServiceController requestAuthorization:^(SKCloudServiceAuthorizationStatus status) {
NSLog(#"status is %ld", (long)status);
SKCloudServiceController *cloudServiceController = [[SKCloudServiceController alloc] init];
[cloudServiceController requestCapabilitiesWithCompletionHandler:^(SKCloudServiceCapability capabilities, NSError * _Nullable error) {
NSLog(#"%lu %#", (unsigned long)capabilities, error);
if (capabilities >= SKCloudServiceCapabilityAddToCloudMusicLibrary || capabilities==SKCloudServiceCapabilityMusicCatalogPlayback) {
NSLog(#"You CAN add to iCloud!");
} else {
NSLog(#"The ability to add Apple Music track is not there. sigh.");
}
}];
}];

Answer 1

You should check for the SKCloudServiceCapabilityMusicCatalogPlayback flag in capabilities. The code in your question checks whether the capabilities variable equals that flag, but you need to use bitwise operators. Here is how you'll do that.
SKCloudServiceController *controller = [SKCloudServiceController new];
[controller requestCapabilitiesWithCompletionHandler:^(SKCloudServiceCapability capabilities, NSError * _Nullable error) {
if (error != nil) {
NSLog(#"Error getting SKCloudServiceController capabilities: %#", error);
} else if (capabilities & SKCloudServiceCapabilityMusicCatalogPlayback) {
// The user has an active subscription
} else {
// The user does *not* have an active subscription
}
}];
You can tell that SKCloudServiceCapabilityMusicCatalogPlayback is a flag and not just a regular constant value because the value uses bitwise operators (the "<<" shown in Apple's documentation).
SKCloudServiceCapabilityMusicCatalogPlayback = 1 << 0
https://developer.apple.com/reference/storekit/skcloudservicecapability/skcloudservicecapabilitymusiccatalogplayback?language=objc