This project aims to prevent the shortcomings that come from the iOS implementation of only allowing a single delegate.


ns plugin add @nativescript/shared-notification-delegate


Import SharedNotificationDelegate and add Observers

import { SharedNotificationDelegate } from '@nativescript/shared-notification-delegate';


    delegateUniqueKey: "myUniqueKey", // ensures uniqueness, if not set or is null/undefined, allows multiple of the same
    userNotificationCenterWillPresentNotificationWithCompletionHandler: (notificationCenter, notification, handler, stop, next) => {
        console.log("notification received by observer");
        // is this notification something I should handle?
        if (shouldHandleThis) {
            // do stuff
            // intercept it and show alert
        // not mine, next should handle


SharedNotificationDelegate Methods

addObserver(observer: DelegateObserver, priority?: number): voidAdds a delegate observer of a certain priority (lower means first). Default priority is 100.
removeObserver(observer: DelegateObserver)removes a DelegateObserver
removeObserverByUniqueKey(key: any)removes a DelegateObserver by its unique key

DelegateObserver Interface

A DelegateObserver can implement 3 methods from UNUserNotificationCenterDelegate with the addition of some details:

interface DelegateObserver {
    center: any /* UNUserNotificationCenter */,
    response: any /* UNNotificationResponse */,
    completionHandler: () => void,
    next: () => void
  ): void
    center: any /* UNUserNotificationCenter */,
    notification: any /* UNNotification */,
    stop: () => void,
    next: () => void
  ): void
    center: any /* UNUserNotificationCenter */,
    notification: any /* UNNotification */,
    completionHandler: (p1: any /* UNNotificationPresentationOptions */) => void,
    next: () => void
  ): void
   * if set to not null/undefined, will ensure only one is registered
  delegateUniqueKey?: any

All the functions are called asynchronously in a chain.

Calling a completionHandler immediately stops the observer chain. next() must be called if the method will not be handling the notification.

Calling stop() on userNotificationCenterOpenSettingsForNotification prevents the event bubbling to the rest.

Only one method will be processed at a time, this means you can take as long as you want (including making http calls, for example), as long as you just call completionHandler, stop and next when you're finished.

If a DelegateObserver has a delegateUniqueKey, the SharedNotificationDelegate will ensure only the latest copy of the observer is present. This is especially useful if debugging with HMR, which may add multiple observers on application reload.


Apache License Version 2.0, January 2004