ExtendableMessageEvent: origin property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2018.
Note: This feature is only available in Service Workers.
The origin read-only property of the ExtendableMessageEvent interface returns the origin of the Client that sent the message.
Value
A string.
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.
js
let port; self.addEventListener("push", (e) => { const 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 = (e) => { console.log(e.origin); port = e.ports[0]; }; Specifications
| Specification |
|---|
| Service Workers # extendablemessage-event-origin |