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ExtendableMessageEvent.ports

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The ports read-only property of the ExtendableMessageEvent interface returns the array containing the MessagePort objects representing the ports of the associated message channel (the channel the message is being sent through.)

Syntax

var myPorts = ExtendableMessageEventInstance.ports;

Value

An array of MessagePort objects.

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) {
  port = e.ports[0];
}

Specifications

Specification Status Comment
Service Workers
The definition of 'ExtendableMessageEvent.ports' in that specification.
Working Draft Initial definition.

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support ? ? 45
45
Service workers (and Push) have been disabled in the Firefox 45 & 52 Extended Support Releases (ESR).
No ? No
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support No ? ? 45 ? No ?

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/ExtendableMessageEvent/ports