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 in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is only available in Service Workers.
The sync event of the ServiceWorkerGlobalScope interface is fired when the page (or worker) that registered the event with the SyncManager 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 like addEventListener(), or set an event handler property.
addEventListener("sync", (event) => { })
onsync = (event) => { }
Event type
A SyncEvent. Inherits from ExtendableEvent and Event.
Event properties
Inherits properties from its ancestor, ExtendableEvent and Event.
SyncEvent.tagRead only-
Returns the developer-defined identifier for this
SyncEvent. SyncEvent.lastChanceRead only-
Returns
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 the onsync property:
self.onsync = (event) => {
// …
};
Specifications
| Specification |
|---|
| Web Background Synchronization # dom-serviceworkerglobalscope-onsync |
Browser compatibility
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sync event
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Legend
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- Full support
- Full support
- No support
- No support
- See implementation notes.