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web api instance method

MessagePort: start() method

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Available in workers

The start() method of the MessagePort interface starts the sending of messages queued on the port. This method is only needed when using 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 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);
function handleMessage(e) {
  para.innerHTML = e.data;
  textInput.value = "";
}

channel.port1.start();

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also