ServiceWorkerGlobalScope.onactivate

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

Browser compatibility

See also

• Using Service Workers
• Service workers basic code example
• Is ServiceWorker ready?
• Promise
• Using web workers