The ExtendableMessageEvent
interface of the Service Worker API represents the event object of a message
event fired on a service worker (when a message is received on the ServiceWorkerGlobalScope
from another context) — extends the lifetime of such events.
This interface inherits from the ExtendableEvent
interface.
Constructor
ExtendableMessageEvent()
- Creates a new
ExtendableMessageEvent
object instance.
Properties
Inherits properties from its parent, ExtendableEvent
.
ExtendableMessageEvent.data
Read only- Returns the event's data. It can be any data type.
ExtendableMessageEvent.origin
Read only- Returns the origin of the
Client
that sent the message. ExtendableMessageEvent.lastEventId
Read only- Represents, in server-sent events, the last event ID of the event source. This is an empty string.
ExtendableMessageEvent.source
Read only- Returns a reference to the
Client
object that sent the message. ExtendableMessageEvent.ports
Read only- Returns the array containing the
MessagePort
objects representing the ports of the associated message channel.
Methods
Inherits methods from its parent, ExtendableEvent
.
Examples
In the below example a page gets a handle to the ServiceWorker
object via ServiceWorkerRegistration.active
, and then calls its postMessage()
function.
// in the page being controlled if (navigator.serviceWorker) { navigator.serviceWorker.register('service-worker.js'); navigator.serviceWorker.addEventListener('message', event => { // event is a MessageEvent object console.log(`The service worker sent me a message: ${event.data}`); }); navigator.serviceWorker.ready.then( registration => { registration.active.postMessage("Hi service worker"); }); }
The service worker can receive the message by listening to the message
event:
// in the service worker addEventListener('message', event => { // event is an ExtendableMessageEvent object console.log(`The client sent me a message: ${event.data}`); event.source.postMessage("Hi client"); });
Specifications
Specification | Status | Comment |
---|---|---|
Service Workers The definition of 'ExtendableMessageEvent' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
ExtendableMessageEvent | Chrome Full support Yes | Edge Full support ≤18 | Firefox
Full support
45
| IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android Full support Yes | Firefox Android Full support 45 | Opera Android ? | Safari iOS No support No | Samsung Internet Android Full support Yes |
ExtendableMessageEvent() constructor | Chrome ? | Edge ? | Firefox
Full support
45
| IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android ? | Firefox Android Full support 45 | Opera Android ? | Safari iOS No support No | Samsung Internet Android ? |
data | Chrome Full support 51 | Edge Full support ≤79 | Firefox
Full support
45
| IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android Full support 51 | Firefox Android Full support 45 | Opera Android ? | Safari iOS No support No | Samsung Internet Android Full support 5.0 |
lastEventId | Chrome ? | Edge Full support 17 | Firefox
Full support
45
| IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android ? | Firefox Android Full support 45 | Opera Android ? | Safari iOS No support No | Samsung Internet Android ? |
origin | Chrome ? | Edge ? | Firefox No support No | IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android ? | Firefox Android No support No | Opera Android ? | Safari iOS No support No | Samsung Internet Android ? |
ports | Chrome ? | Edge ? | Firefox
Full support
45
| IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android ? | Firefox Android Full support 45 | Opera Android ? | Safari iOS No support No | Samsung Internet Android ? |
source | Chrome ? | Edge ? | Firefox
Full support
45
| IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android ? | Firefox Android Full support 45 | Opera Android ? | Safari iOS No support No | Samsung Internet Android ? |
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.