ServiceWorkerRegistration
=========================

The **`ServiceWorkerRegistration`** interface of the Service Worker API represents the service worker registration. You register a service worker to control one or more pages that share the same origin.

The lifetime of a service worker registration is beyond that of the `ServiceWorkerRegistration` objects that represent them within the lifetime of their corresponding service worker clients. The browser maintains a persistent list of active `ServiceWorkerRegistration` objects.

**Note:** This feature is available in Web Workers

EventTarget

ServiceWorkerRegistrationInstance properties
-------------------

*Also inherits properties from its parent interface,* `EventTarget`.

`ServiceWorkerRegistration.active` Read only 

Returns a service worker whose state is `activating` or `activated`. This is initially set to `null`. An active worker will control a `Client` if the client's URL falls within the scope of the registration (the `scope` option set when `ServiceWorkerContainer.register` is first called.)

`ServiceWorkerRegistration.backgroundFetch` Read only  
Experimental

Returns a reference to a `BackgroundFetchManager` object, which manages background fetch operations.

`ServiceWorkerRegistration.cookies` Read only  
Experimental

Returns a reference to the `CookieStoreManager` interface, which allows subscribe and unsubscribe to cookie change events.

`ServiceWorkerRegistration.index` Read only  
Experimental

Returns a reference to the `ContentIndex` interface, for managing indexed content for offline viewing.

`ServiceWorkerRegistration.installing` Read only 

Returns a service worker whose state is `installing`. This is initially set to `null`.

`ServiceWorkerRegistration.navigationPreload` Read only 

Returns the instance of `NavigationPreloadManager` associated with the current service worker registration.

`ServiceWorkerRegistration.paymentManager` Read only  
Experimental

Returns a payment app's `PaymentManager` instance, which is used to manage various payment app functionality.

`ServiceWorkerRegistration.periodicSync` Read only  
Experimental

Returns a reference to the `PeriodicSyncManager` interface, which allows for registering of tasks to run at specific intervals.

`ServiceWorkerRegistration.pushManager` Read only 

Returns a reference to the `PushManager` interface for managing push subscriptions including subscribing, getting an active subscription, and accessing push permission status.

`ServiceWorkerRegistration.scope` Read only 

Returns a unique identifier for a service worker registration. This must be on the same origin as the document that registers the `ServiceWorker`.

`ServiceWorkerRegistration.sync` Read only  
Experimental

Returns a reference to the `SyncManager` interface, which manages background synchronization processes.

`ServiceWorkerRegistration.updateViaCache` Read only 

Returns a string indicating what is the cache strategy to use when updating the service worker scripts. It can be one of the following: `imports`, `all`, or `none`.

`ServiceWorkerRegistration.waiting` Read only 

Returns a service worker whose state is `installed`. This is initially set to `null`.

Instance methods
----------------

*Also inherits methods from its parent interface,* `EventTarget`.

`ServiceWorkerRegistration.getNotifications()`

Returns a list of the notifications in the order that they were created from the current origin via the current service worker registration.

`ServiceWorkerRegistration.showNotification()`

Displays the notification with the requested title.

`ServiceWorkerRegistration.unregister()`

Unregisters the service worker registration and returns a `Promise`. The service worker will finish any ongoing operations before it is unregistered.

`ServiceWorkerRegistration.update()`

Checks the server for an updated version of the service worker without consulting caches.

Events
------

`updatefound`

Fired any time the `ServiceWorkerRegistration.installing` property acquires a new service worker.

Examples
--------

In this example, the code first checks whether the browser supports service workers and if so registers one. Next, it adds an `updatefound` listener in which it uses the service worker registration to listen for further changes to the service worker's state. If the service worker hasn't changed since the last time it was registered, then the `updatefound` event will not be fired.


```js
if ("serviceWorker" in navigator) {
  navigator.serviceWorker
    .register("/sw.js")
    .then((registration) => {
      registration.addEventListener("updatefound", () => {
        // If updatefound is fired, it means that there's
        // a new service worker being installed.
        const installingWorker = registration.installing;
        console.log(
          "A new service worker is being installed:",
          installingWorker,
        );

        // You can listen for changes to the installing service worker's
        // state via installingWorker.onstatechange
      });
    })
    .catch((error) => {
      console.error(`Service worker registration failed: ${error}`);
    });
} else {
  console.error("Service workers are not supported.");
}
```

Specifications
--------------

| Specification |
| --- |
| Service Workers # serviceworkerregistration-interface |
| Push API # extensions-to-the-serviceworkerregistration-interface |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* Using Service Workers
* Service workers basic code example
* Using web workers