The lastEventID read-only property of the ExtendableMessageEvent interface represents, in server-sent events, the last event ID of the event source. This is an empty string.
ExtendableMessageEvent.lastEventId
Value
A DOMString.
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.lastEventId); port = e.ports[0]; }
Specifications
| Specification |
|---|
| Service Workers 1 # extendablemessage-event-lasteventid |
Browser compatibility
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
lastEventId |
51
|
17
|
44
Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.
|
No
|
38
|
11.1
|
51
|
51
|
44
|
41
|
11.3
|
5.0
|
See also
© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/ExtendableMessageEvent/lastEventId
