The MessageChannel()
constructor of the MessageChannel
interface returns a new MessageChannel
object with two new MessagePort
objects.
Note: This feature is available in Web Workers
The MessageChannel()
constructor of the MessageChannel
interface returns a new MessageChannel
object with two new MessagePort
objects.
Note: This feature is available in Web Workers
new MessageChannel();
A newly created MessageChannel
object.
In the following code block, you can see a new channel being created using the MessageChannel.MessageChannel
constructor. When the IFrame has loaded, we pass port2
to the IFrame using MessagePort.postMessage
along with a message. The handleMessage
handler then responds to a message being sent back from the IFrame (using onmessage
), putting it into a paragraph. MessageChannel.port1
is listened to, to check when the message arrives.
var channel = new MessageChannel(); var para = document.querySelector('p'); var ifr = document.querySelector('iframe'); var otherWindow = ifr.contentWindow; ifr.addEventListener("load", iframeLoaded, false); function iframeLoaded() { otherWindow.postMessage('Hello from the main page!', '*', [channel.port2]); } channel.port1.onmessage = handleMessage; function handleMessage(e) { para.innerHTML = e.data; }
For a full working example, see our channel messaging basic demo on GitHub (run it live too).
Specification |
---|
HTML Standard # dom-messagechannel-dev |
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
MessageChannel |
1
|
12
|
41
|
10
|
10.6
|
5
|
4.4
|
18
|
41
|
11
|
4.2
|
1.0
|
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/MessageChannel/MessageChannel