The ServiceWorkerGlobalScope
interface of the ServiceWorker API represents the global execution context of a service worker.
Developers should keep in mind that the ServiceWorker state is not persisted across the termination/restart cycle, so each event handler should assume it's being invoked with a bare, default global state.
Once successfully registered, a service worker can and will be terminated when idle to conserve memory and processor power. An active service worker is automatically restarted to respond to events, such as ServiceWorkerGlobalScope.onfetch
or ServiceWorkerGlobalScope.onmessage
.
Additionally, synchronous requests are not allowed from within a service worker — only asynchronous requests, like those initiated via the fetch()
method, can be used.
This interface inherits from the WorkerGlobalScope
interface, and its parent EventTarget
, and therefore implements properties from WindowTimers
, WindowBase64
, and WindowEventHandlers
.
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Properties
ServiceWorkerGlobalScope.clients
Read only- Contains the
Clients
object associated with the service worker. ServiceWorkerGlobalScope.registration
Read only- Contains the
ServiceWorkerRegistration
object that represents the service worker's registration. ServiceWorkerGlobalScope.caches
Read only- Contains the
CacheStorage
object associated with the service worker.
Events
activate
- Occurs when a
ServiceWorkerRegistration
acquires a newServiceWorkerRegistration.active
worker.
Also available via theServiceWorkerGlobalScope.onactivate
property. contentdelete
- Occurs when an item is removed from the
Content Index
.
Also available via theServiceWorkerGlobalScope.oncontentdelete
property. fetch
- Occurs when a
fetch()
is called.
Also available via theServiceWorkerGlobalScope.onfetch
property. install
- Occurs when a
ServiceWorkerRegistration
acquires a newServiceWorkerRegistration.installing
worker.
Also available via theServiceWorkerGlobalScope.oninstall
property. message
- Occurs when incoming messages are received. Controlled pages can use the
MessagePort.postMessage()
method to send messages to service workers. The service worker can optionally send a response back via theMessagePort
exposed inevent.data.port
, corresponding to the controlled page.
Also available via theServiceWorkerGlobalScope.onmessage
property. notificationclick
- Occurs when a user clicks on a displayed notification.
Also available via theServiceWorkerGlobalScope.onnotificationclick
property. notificationclose
- Occurs — when a user closes a displayed notification.
Also available via theServiceWorkerGlobalScope.onnotificationclose
property. push
- Occurs when a server push notification is received.
Also available via theServiceWorkerGlobalScope.onpush
property. pushsubscriptionchange
- Occurs when a push subscription has been invalidated, or is about to be invalidated (e.g. when a push service sets an expiration time).
Also available via theServiceWorkerGlobalScope.onpushsubscriptionchange
property. sync
- Triggered when a call to
SyncManager.register
is made from a service worker client page. The attempt to sync is made either immediately if the network is available or as soon as the network becomes available.
Also available via theServiceWorkerGlobalScope.onsync
property.
Methods
ServiceWorkerGlobalScope.skipWaiting()
- Allows the current service worker registration to progress from waiting to active state while service worker clients are using it.
ServiceWorkerGlobalScope
implements WorkerGlobalScope
— which implements WindowOrWorkerGlobalScope
. Therefore it also has the following property available to it:
GlobalFetch.fetch()
- Starts the process of fetching a resource. This returns a promise that resolves to the
Response
object representing the response to your request. This algorithm is the entry point for the fetch handling handed to the service worker context.
Examples
This code snippet is from the service worker prefetch sample (see prefetch example live.) The ServiceWorkerGlobalScope.onfetch
event handler listens for the fetch
event. When fired, the code returns a promise that resolves to the first matching request in the Cache
object. If no match is found, the code fetches a response from the network.
The code also handles exceptions thrown from the fetch()
operation. Note that an HTTP error response (e.g., 404) will not trigger an exception. It will return a normal response object that has the appropriate error code set.
self.addEventListener('fetch', function(event) { console.log('Handling fetch event for', event.request.url); event.respondWith( caches.match(event.request).then(function(response) { if (response) { console.log('Found response in cache:', response); return response; } console.log('No response found in cache. About to fetch from network...'); return fetch(event.request).then(function(response) { console.log('Response from network is:', response); return response; }, function(error) { console.error('Fetching failed:', error); throw error; }); }) ); });
Specifications
Specification | Status | Comment |
---|---|---|
Service Workers The definition of 'ServiceWorkerGlobalScope' in that specification. |
Working Draft | Initial definition |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
ServiceWorkerGlobalScope | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
activate event | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
caches | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
clients | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
install event | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
message event | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
notificationclick event | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android No support No | 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 |
onabortpayment | Chrome
Full support
61
| Edge
Full support
≤79
| Firefox ? | IE No support No | Opera ? | Safari Full support 11.1 | WebView Android No support No | Chrome Android
Full support
61
| Firefox Android ? | Opera Android ? | Safari iOS Full support 11.3 | Samsung Internet Android No support No |
onactivate | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onbackgroundfetchabort | Chrome Full support 74 | Edge No support No | Firefox No support No | IE No support No | Opera Full support 62 | Safari No support No | WebView Android No support No | Chrome Android Full support 74 | Firefox Android No support No | Opera Android Full support 53 | Safari iOS No support No | Samsung Internet Android Full support 11.0 |
onbackgroundfetchclick | Chrome Full support 74 | Edge No support No | Firefox No support No | IE No support No | Opera Full support 62 | Safari No support No | WebView Android No support No | Chrome Android Full support 74 | Firefox Android No support No | Opera Android Full support 53 | Safari iOS No support No | Samsung Internet Android Full support 11.0 |
onbackgroundfetchfail | Chrome Full support 74 | Edge No support No | Firefox No support No | IE No support No | Opera Full support 62 | Safari No support No | WebView Android No support No | Chrome Android Full support 74 | Firefox Android No support No | Opera Android Full support 53 | Safari iOS No support No | Samsung Internet Android Full support 11.0 |
onbackgroundfetchsuccess | Chrome Full support 74 | Edge No support No | Firefox No support No | IE No support No | Opera Full support 62 | Safari No support No | WebView Android No support No | Chrome Android Full support 74 | Firefox Android No support No | Opera Android Full support 53 | Safari iOS No support No | Samsung Internet Android Full support 11.0 |
oncanmakepayment | Chrome
Full support
61
| Edge
Full support
≤79
| Firefox ? | IE No support No | Opera ? | Safari ? | WebView Android No support No | Chrome Android
Full support
61
| Firefox Android ? | Opera Android ? | Safari iOS ? | Samsung Internet Android No support No |
onfetch | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
oninstall | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onmessage | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onmessageerror | Chrome ? | Edge ? | Firefox ? | IE No support No | Opera ? | Safari ? | WebView Android ? | Chrome Android ? | Firefox Android ? | Opera Android ? | Safari iOS ? | Samsung Internet Android ? |
onnotificationclick | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onnotificationclose | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onpaymentrequest | Chrome
Full support
57
| Edge
Full support
≤79
| Firefox ? | IE No support No | Opera ? | Safari ? | WebView Android No support No | Chrome Android
Full support
57
| Firefox Android ? | Opera Android ? | Safari iOS ? | Samsung Internet Android No support No |
onpush | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onpushsubscriptionchange | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
onsync | Chrome Full support 49 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 49 | Chrome Android Full support 49 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 5.0 |
push event | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
pushsubscriptionchange event | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
registration | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari Full support 11.1 | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 4.0 |
skipWaiting | Chrome Full support 40 | Edge Full support ≤79 | Firefox
Full support
44
| IE No support No | Opera Full support 24 | Safari No support No | WebView Android Full support 40 | Chrome Android Full support 40 | Firefox Android Full support 44 | Opera Android Full support 24 | Safari iOS No support No | Samsung Internet Android Full support 4.0 |
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.