SyncManager: register() method

{{APIRef("Background Sync")}} {{AvailableInWorkers}} 

The register() method of the {{domxref("SyncManager")}}  interface registers a synchronization event, triggering a {{domxref("ServiceWorkerGlobalScope.sync_event", "sync")}}  event inside the associated service worker as soon as network connectivity is available.

Syntax

register(tag)

Parameters

• tag
  • : An identifier for this synchronization event. This will be the value of the tag property of the {{domxref("SyncEvent")}}  that gets passed into the service worker’s {{domxref("ServiceWorkerGlobalScope.sync_event", "sync")}}  event handler.

Return value

A {{jsxref("Promise")}}  that resolves to {{jsxref("undefined")}} .

Exceptions

• InvalidStateError {{domxref("DOMException")}} 
  • : Thrown if current service worker is not active.
• NotAllowedError {{domxref("DOMException")}} 
  • : Thrown if background sync has been disabled by the user.

Examples

The following asynchronous function registers a background sync from a browsing context:

async function syncMessagesLater() {
  const registration = await navigator.serviceWorker.ready;
  try {
    await registration.sync.register("sync-messages");
  } catch {
    console.log("Background Sync could not be registered!");
  }
}

Specifications

{{Specifications}} 

Browser compatibility

{{Compat}}