Play Push Notification Sound Effect when app is not running (Mac) - macos

Question

I'm adding Push Notifications to my Mac app. The notifications are showing up just fine, but for some reason I can't get the sound effects to play the way I would think they should.
I'm passing in a custom sound to play, "custom.caf" in the apns payload. This works currently for our iOS app. It doesn't play anything when passed into the Mac app. Digging around in the very limited Apple documentation, the PushyMac app shows that you have to play the sound manually based on the userInfo dictionary that comes in for the push. If I play the sound manually while the app is running, I get the sound effect to play.
My problem is when the app is closed and not running. I still get push notifications as expected, but no sounds play. From what I can tell, I'm just screwed. I have other Mac apps that still manage to play sounds when they aren't running. Specifically my email app, Spark. So I know it is possible, but I can't figure out what the secret sauce is to pull it off. Please help!!

Answer 1

It's quite simple to implement the custom sound capability for Apple Push Notifications; the problem is that the documentation does not mention what is required to do this.
The critical component that is required is an extension — (eg. using the Today Extension). Creating a new target in your project including the extension, your custom sound(s), and the standard APN functions are all that's required. The key to getting the custom sounds working though while your application isn't running is simply having the extension (and it's included NotificationCenter.framework) present in your application.
Add New Target > Today Extension:
Today Extension > Build Phases > Copy Bundle Resources > Custom Sound:
The only specific APN functions that need to be in your main application are the following:
func applicationDidFinishLaunching(_ aNotification: Notification) {
NSApplication.shared().
registerForRemoteNotifications(matching:
[.alert, .sound, .badge])
NSApp.dockTile.badgeLabel = nil
}
func application(_ application: NSApplication,
didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
}
func application(_ application: NSApplication, didReceiveRemoteNotification
userInfo: [String : Any]) {
}
func application(_ application: NSApplication,
didFailToRegisterForRemoteNotificationsWithError error: Error) {
print("could not register for notfications: \(error)")
}
If you are getting two sounds playing at the same time it's likely that you've got code that is calling AudioServicesPlaySystemSound and can be removed as the NotificationCenter.framework seems to handle all that without adding anything additional.