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.
Properties
ServiceWorkerContainer.controller
Read only- Returns a
ServiceWorker
object if its state isactivated
(the same object returned byServiceWorkerRegistration.active
). This property returnsnull
during a force-refresh request (Shift + refresh) or if there is no active worker.
ServiceWorkerContainer.ready
Read only- Provides a way of delaying code execution until a service worker is active. It returns a
Promise
that will never reject, and which waits indefinitely until theServiceWorkerRegistration
associated with the current page has anServiceWorkerRegistration.active
worker. Once that condition is met, it resolves with theServiceWorkerRegistration
.
Events
controllerchange
- Occurs when the document's associated
ServiceWorkerRegistration
acquires a newactive
worker.
Also available via theServiceWorkerContainer.oncontrollerchange
property. error
- Fired whenever an error occurs in the associated service workers.
Also available via theServiceWorkerContainer.onerror
property. message
- Occurs when incoming messages are received by the
ServiceWorkerContainer
object (e.g. via aMessagePort.postMessage()
call.)
Also available via theServiceWorkerContainer.onmessage
property.
Methods
ServiceWorkerContainer.register()
- Creates or updates a
ServiceWorkerRegistration
for the givenscriptURL
. ServiceWorkerContainer.getRegistration()
- Gets a
ServiceWorkerRegistration
object whose scope matches the provided document URL. The method returns aPromise
that resolves to aServiceWorkerRegistration
orundefined
. ServiceWorkerContainer.getRegistrations()
- Returns all
ServiceWorkerRegistration
objects associated with aServiceWorkerContainer
in an array. The method returns aPromise
that resolves to an array ofServiceWorkerRegistration
. 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.
Examples
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(function(registration) { console.log('Service worker registration succeeded:', registration); // At this point, you can optionally do something // with registration. See /docs/Web/API/ServiceWorkerRegistration }).catch(function(error) { console.log('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 = function() { console.log('This page is now controlled by:', navigator.serviceWorker.controller); }; } else { console.log('Service workers are not supported.'); }
Specifications
Specification | Status | Comment |
---|---|---|
Service Workers The definition of 'ServiceWorkerContainer' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
ServiceWorkerContainer | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
controller | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
getRegistration | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
getRegistrations | Chrome Full support 45 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 45 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
message event | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
oncontrollerchange | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onerror | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onmessage | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onmessageerror | Chrome No support No | Edge No support 17 — 79 | Firefox Full support Yes | IE No support No | Opera ? | Safari Full support Yes | WebView Android No support No | Chrome Android No support No | Firefox Android Full support Yes | Opera Android ? | Safari iOS Full support Yes | Samsung Internet Android No support No |
ready | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
register | Chrome Full support 40 | Edge
Full support
17
| Firefox
Full support
44
| IE No support No | Opera Full support 27 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 27 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
startMessages | Chrome Full support 74 | Edge Full support ≤79 | Firefox Full support 64 | IE No support No | Opera Full support 62 | Safari Full support Yes | WebView Android Full support 74 | Chrome Android Full support 74 | Firefox Android Full support 64 | Opera Android Full support 50 | Safari iOS Full support Yes | Samsung Internet Android Full support 11.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Experimental. Expect behavior to change in the future.
- Experimental. Expect behavior to change in the future.
- See implementation notes.
- See implementation notes.
- User must explicitly enable this feature.
- User must explicitly enable this feature.