MessagePort: start() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
Note: This feature is available in Web Workers.
The start()
method of the MessagePort
interface starts the sending of messages queued on the port. This method is only needed
when using EventTarget.addEventListener
; it is implied when using
onmessage
.
Syntax
start()
Parameters
None.
Return value
None (undefined
).
Examples
In the following code block, you can see a handleMessage
handler function,
run when a message is sent back to this document using onmessage
:
channel.port1.onmessage = handleMessage;
function handleMessage(e) {
para.innerHTML = e.data;
}
Another option would be to do this using EventTarget.addEventListener
,
however, when this method is used, you need to explicitly call start()
to
begin the flow of messages to this document:
channel.port1.addEventListener("message", handleMessage, false);
function handleMessage(e) {
para.innerHTML = e.data;
textInput.value = "";
}
channel.port1.start();
Specifications
Specification |
---|
HTML Standard # dom-messageport-start-dev |
Browser compatibility
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