ThePeriodicSyncEvent interface of theWeb Periodic Background Synchronization API provides a way to run tasks in the service worker with network connectivity.

An instance of this event is passed to theperiodicsync handler. This happens periodically, at an interval greater than or equal to that set in thePeriodicSyncManager.register() method. Other implementation-specific factors such as the user's engagement with the site decide the actual interval.

Constructor

PeriodicSyncEvent()Experimental

Creates a newPeriodicSyncEvent object. This constructor is not typically used. The browser creates these objects itself and provides them toonperiodicsync callback.

Instance properties

Inherits properties from its parent,ExtendableEvent.

PeriodicSyncEvent.tagRead onlyExperimental

Returns the developer-defined identifier for thisPeriodicSyncEvent. Multiple tags can be used by the web app to run different periodic tasks at different frequencies.

Instance methods

Inherits methods from its parent,ExtendableEvent.

Examples

The following example shows how to respond to a periodic sync event in the service worker.

self.addEventListener("periodicsync", (event) => {  if (event.tag === "get-latest-news") {    event.waitUntil(fetchAndCacheLatestNews());  }});

fetchAndCacheLatestNews is a developer defined function.

Specifications

Browser compatibility

See also

• Richer offline experiences with the Periodic Background Sync API