UNUserNotificationCenter. Notifications are not allowed for this application - swift

Question

I noob in development application on OSX. I want to create app with Share extension. After content loading I want to show Notification, but I getting error "Notifications are not allowed for this application". I don't understand why requestAuthorization method not show dialog windows with permission, and how I can allow application to send notifications.
This is my code:
import Cocoa
import UserNotifications
class ShareViewController: NSViewController {
override func loadView() {
self.view = NSView()
// Insert code here to customize the view
let item = self.extensionContext!.inputItems[0] as! NSExtensionItem
NSLog("Attachment = %#", item.attachments! as NSArray)
showNotification()
let outputItem = NSExtensionItem()
let outputItems = [outputItem]
self.extensionContext!.completeRequest(returningItems: outputItems, completionHandler: nil)
}
func showNotification() -> Void {
let notificationCenter = UNUserNotificationCenter.current()
notificationCenter.requestAuthorization(options: [.alert, .badge]) {
(granted, error) in
if granted {
print("Yay!")
} else {
print("D'oh") // Print this, not authorized
}
}
let content = UNMutableNotificationContent()
content.title = "Hello"
content.body = "This is example"
content.sound = UNNotificationSound.default
content.badge = 1
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)
notificationCenter.add(request) { (error : Error?) in
if let theError = error {
print(theError) // Print Domain=UNErrorDomain Code=1 "Notifications are not allowed for this application"
}
}
}
}

Answer 1

I don't see anywhere in the documentation that says you can't schedule new Local Notifications from an extension. I do however see an apple support ticket where someone had to deal with this issue, as do I.
Basically this failure is a race-condition. The key is to not call the contentHandler of this extension method:
override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: #escaping (UNNotificationContent) -> Void) {
until after the completion handler of
notificationCenter.add(request: UNNotificationRequest>, withCompletionHandler: ((Error?) -> Void)
is called. It worked for me. Make sense?

Answer 2

Apple does't allow send Notifications from Share extensions.
Documentation