Baseline Widely available *
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The ServiceWorkerContainer
interface of the Service Worker API provides an object representing the service worker as an overall unit in the network ecosystem, including facilities to register, unregister and update service workers, and access the state of service workers and their registrations.
Most importantly, it exposes the ServiceWorkerContainer.register()
method used to register service workers, and the ServiceWorkerContainer.controller
property used to determine whether or not the current page is actively controlled.
ServiceWorkerContainer
objects are exposed in the Window scope through Navigator.serviceWorker
and in workers using WorkerNavigator.serviceWorker
(if supported â check browser compatibility).
ServiceWorkerContainer.controller
Read only
A ServiceWorker
object that represents the active service worker controlling the current page or null
if the page has no active or activating service worker.
ServiceWorkerContainer.ready
Read only
Returns a Promise
that resolves with the ServiceWorkerRegistration
associated with the current page, but only when there is an active service worker. This provides a mechanism to defer code execution until a service worker is active.
ServiceWorkerContainer.getRegistration()
Gets a ServiceWorkerRegistration
object whose scope matches the provided document URL. The method returns a Promise
that resolves to a ServiceWorkerRegistration
or undefined
.
ServiceWorkerContainer.getRegistrations()
Returns all ServiceWorkerRegistration
objects associated with a ServiceWorkerContainer
in an array. The method returns a Promise
that resolves to an array of ServiceWorkerRegistration
.
ServiceWorkerContainer.register()
Creates or updates a ServiceWorkerRegistration
for the given scriptURL
.
ServiceWorkerContainer.startMessages()
Explicitly starts the flow of messages being dispatched from a service worker to pages under its control (e.g., sent via Client.postMessage()
). This can be used to react to sent messages earlier, even before that page's content has finished loading.
controllerchange
Fired when the document's associated ServiceWorkerRegistration
acquires a new active
worker.
message
Fired when incoming messages are received by the ServiceWorkerContainer
object (e.g., via a MessagePort.postMessage()
call).
messageerror
Fired when incoming messages can not deserialized by the ServiceWorkerContainer
object (e.g., via a MessagePort.postMessage()
call).
The example below first checks to see if the browser supports service workers. If supported, the code registers the service worker and determines if the page is actively controlled by the service worker. If it isn't, it prompts the user to reload the page so the service worker can take control. The code also reports any registration failures.
if ("serviceWorker" in navigator) {
// Register a service worker hosted at the root of the
// site using the default scope.
navigator.serviceWorker
.register("/sw.js")
.then((registration) => {
console.log("Service worker registration succeeded:", registration);
// At this point, you can optionally do something
// with registration. See https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerRegistration
})
.catch((error) => {
console.error(`Service worker registration failed: ${error}`);
});
// Independent of the registration, let's also display
// information about whether the current page is controlled
// by an existing service worker, and when that
// controller changes.
// First, do a one-off check if there's currently a
// service worker in control.
if (navigator.serviceWorker.controller) {
console.log(
"This page is currently controlled by:",
navigator.serviceWorker.controller,
);
}
// Then, register a handler to detect when a new or
// updated service worker takes control.
navigator.serviceWorker.oncontrollerchange = () => {
console.log(
"This page is now controlled by",
navigator.serviceWorker.controller,
);
};
} else {
console.log("Service workers are not supported.");
}
Specifications Browser compatibility See also
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4