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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 ready read-only property of the ServiceWorkerContainer interface defines whether a service worker is ready to control a page or not. It returns a Promise that will never reject, which resolves to a ServiceWorkerRegistration with an ServiceWorkerRegistration.active worker.
Syntax
navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) { ... });
Example
function subscribe() {
var subscribeButton = document.querySelector('.js-subscribe-button');
subscribeButton.disabled = false;
navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) {
serviceWorkerRegistration.pushManager.subscribe()
.then(function(subscription) {
// The subscription was successful
subscribeButton.disabled = true;
return sendSubscriptionToServer(subscription);
})
.catch(function(error) {
if (Notification.permission === 'denied') {
console.log('Permission for Notifications was denied');
subscribeButton.disabled = true;
} else {
console.log('Unable to subscribe to push.', error);
subscribeButton.disabled = false;
}
});
});
}
Specifications
| Specification | Status | Comment |
|---|---|---|
| Service Workers The definition of 'ServiceWorkerRegistration.ready' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | 38.0 | 44.0 (44.0)[1] | No support | 24 | 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 | 38.0 |
[1] Service workers (and Push) have been disabled in the Firefox 45 Extended Support Release (ESR.)