ServiceWorkerGlobalScope: sync event
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Secure context: This feature is available only insecure contexts (HTTPS), in some or allsupporting browsers.
Note: This feature is only available inService Workers.
Thesync event of theServiceWorkerGlobalScope interface is fired when the page (or worker) that registered the event with theSyncManager is running and as soon as network connectivity is available.
This event is not cancelable and does not bubble.
Syntax
Use the event name in methods likeaddEventListener(), or set an event handler property.
addEventListener("sync", (event) => { })onsync = (event) => { }Event type
ASyncEvent. Inherits fromExtendableEvent andEvent.
Event properties
Inherits properties from its ancestor,ExtendableEvent andEvent.
SyncEvent.tagRead onlyReturns the developer-defined identifier for this
SyncEvent.SyncEvent.lastChanceRead onlyReturns
trueif the user agent will not make further synchronization attempts after the current attempt.
Examples
The following example shows how to respond to a sync event in the service worker.
self.addEventListener("sync", (event) => { if (event.tag === "sync-messages") { event.waitUntil(sendOutboxMessages()); }});You can also set up the event handler using theonsync property:
self.onsync = (event) => { // …};Specifications
| Specification |
|---|
| Web Background Synchronization # dom-serviceworkerglobalscope-onsync |