Retrieves an existing push subscription.
Retrieves an existing push subscription. It returns a Promise that resolves to a PushSubscription object containing details of an existing subscription. If no existing subscription exists, this resolves to a null value.
The permissionState() method of the PushManager interface returns a Promise that resolves to a DOMString indicating the permission state of the push manager.
The permissionState() method of the PushManager interface returns a Promise that resolves to a DOMString indicating the permission state of the push manager. Possible values are 'prompt', 'denied', or 'granted'.
An object containing optional configuration parameters. It can have the following properties:
The subscribe() method of the PushManager interface subscribes to a push service.
The subscribe() method of the PushManager interface subscribes to a push service.
It returns a Promise that resolves to a PushSubscription object containing details of a push subscription. A new push subscription is created if the current service worker does not have an existing subscription.
The PushManager interface of the Push API provides a way to receive notifications from third-party servers as well as request URLs for push notifications.
This interface is accessed via the ServiceWorkerRegistration.pushManager property.
The Push API is currently specified here: https://www.w3.org/TR/2018/WD-push-api-20181026/