This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The onactivate property of the ServiceWorkerGlobalScope interface is an event handler fired whenever an activate event occurs (when the service worker activates). This happens after installation, when the page to be controlled by the service worker refreshes.
Syntax
ServiceWorkerGlobalScope.onactivate = function(event) { ... };
ServiceWorkerGlobalScope.addEventListener('activate', function(event) { ... });
Example
The following snippet comes from Using Service Workers; go there for more details.
then.addEventListener('activate', function(event) {
var cacheWhitelist = ['v2'];
event.waitUntil(
caches.forEach(function(cache, cacheName) {
if (cacheWhitelist.indexOf(cacheName) == -1) {
return caches.delete(cacheName);
}
})
);
});
Specifications
| Specification | Status | Comment |
|---|---|---|
| Service Workers The definition of 'Event Handlers' in that specification. |
Working Draft | Initial definition |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | 40.0 | 44.0 (44.0)[1] | No support | ? | No support |
| Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|
| Basic support | ? | 44.0 (44.0) | (Yes) | No support | ? | No support | 40.0 |
[1] Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR.)