The ServiceWorkerGlobalScope.onpush event of the ServiceWorkerGlobalScope interface is fired whenever a push message is received by a service worker via a push server.
The ServiceWorkerGlobalScope.onpushsubscriptionchange event of the ServiceWorkerGlobalScope interface is fired whenever a push subscription has been invalidated (or is about to become so). This offers an opportunity to resubscribe in order to continue receiving push messages, if desired. This might happen if, for example, the push service sets an expiration time a subscription.
The pushManager property of the ServiceWorkerRegistration interface returns a reference to the PushManager interface for managing push subscriptions; this includes support for subscribing, getting an active subscription, and accessing push permission status.