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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 controller read-only property of the ServiceWorkerContainer interface returns a ServiceWorker object if its state is activated (the same object returned by ServiceWorkerRegistration.active). This property returns null if the request is a force refresh (Shift + refresh) or if there is no active worker.
Syntax
var myController = navigator.serviceWorker.controller;
Example
if ('serviceWorker' in navigator) {
navigator.serviceWorker.register('service-worker.js', {scope: './'}).then(function(r) {
if (navigator.serviceWorker.controller) {
document.querySelector('#status').textContent = 'A service worker is currently handling network operations.';
} else {
document.querySelector('#status').textContent = 'Please reload this page to allow the service worker to handle network operations.';
}
}).catch(function(error) {
document.querySelector('#status').textContent = error;
});
} else {
document.querySelector('#status').textContent = 'Service workers are not supported.';
}
Specifications
| Specification | Status | Comment |
|---|---|---|
| Service Workers The definition of 'ServiceWorkerRegistration.controller' 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 | 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 | ? |
[1] Service workers (and Push) have been disabled in the Firefox 45 Extended Support Release (ESR.)