ServiceWorkerRegistration - Web APIs 编辑

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.

Properties

Also implements properties from its parent interface, EventTarget.

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.installing Read only

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

ServiceWorkerRegistration.waiting Read only

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

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 ServiceWorkerClient if the client's URL falls within the scope of the registration (the scope option set when ServiceWorkerContainer.register is first called.)

ServiceWorkerRegistration.navigationPreload Read only

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

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.sync  Read only  

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

ServiceWorkerRegistration.index Read only  

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

Unimplemented properties

serviceWorkerRegistration.periodicSync Read only

Returns a reference to the PeriodicSyncManager interface, which manages periodic background synchronization processes. This was mentioned as an idea in the SW explainer at some point, but as yet has not been implemented anywhere.

Event handlers

ServiceWorkerRegistration.onupdatefound Read only

An EventListener property called whenever an event of type updatefound is fired; it is fired any time the ServiceWorkerRegistration.installing property acquires a new service worker.

Methods

Also implements methods from its parent interface, EventTarget.

ServiceWorkerRegistration.getNotifications()

Returns a Promise that resolves to an array of Notification objects.

ServiceWorkerRegistration.showNotification()

Displays the notification with the requested title.

ServiceWorkerRegistration.update()

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

ServiceWorkerRegistration.unregister()

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

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.

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw.js')
  .then(function(registration) {
    registration.addEventListener('updatefound', function() {
      // If updatefound is fired, it means that there's
      // a new service worker being installed.
      var 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(function(error) {
    console.log('Service worker registration failed:', error);
  });
} else {
  console.log('Service workers are not supported.');
}

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Using Service Workers
• Service workers basic code example
• Is ServiceWorker ready?
• Promise
• Using web workers