This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The ExtendableMessageEvent
interface of the ServiceWorker API
represents the event object of a message
event fired on a service worker (when a channel message is received on the ServiceWorkerGlobalScope
from another context) — extends the lifetime of such events.
This interface inherits from the ExtendableEvent
interface.
Constructor
ExtendableMessageEvent.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
ServiceWorkerClient
that sent the message ExtendableMessageEvent.lastEventId
Read only- Represents, in server-sent events, the last event ID of the event source.
ExtendableMessageEvent.source
Read only- Returns a reference to the service worker 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
When the following code is used inside a service worker to respond to a push messages by sending the data received via PushMessageData
to the main context via a channel message, the event object of onmessage
will be a ExtendableMessageEvent
.
var port; self.addEventListener('push', function(e) { var obj = e.data.json(); if(obj.action === 'subscribe' || obj.action === 'unsubscribe') { port.postMessage(obj); } else if(obj.action === 'init' || obj.action === 'chatMsg') { port.postMessage(obj); } }); self.onmessage = function(e) { console.log(e); port = e.ports[0]; }
Specifications
Specification | Status | Comment |
---|---|---|
Service Workers The definition of 'ExtendableMessageEvent' in that specification. |
Editor's Draft | Initial definition. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | (Yes) | 45.0 (45.0)[1] | No support | ? | No support |
data property | 51.0 | ? | ? | ? | ? |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|---|
Basic support | No support | No support | (Yes) | (Yes) | No support | ? | No support | (Yes) |
data property | No support | No support | ? | ? | ? | ? | ? | 51.0 |
[1] Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR.)