Worker: messageerror event

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Note: This feature is available in Web Workers, except for Service Workers.

The messageerror event is fired on a Worker object when it receives a message that can't be deserialized.

This event is not cancellable and does not bubble.

Syntax

Use the event name in addEventListener():

js
addEventListener("messageerror", (event) => { })

Alternatively, assign to the event handler property of the interface:

js
onmessageerror = (event) => { }

Event type

A MessageEvent. Inherits from Event.

Event MessageEvent

Examples

Create a worker, and listen for message and messageerror events using addEventListener():

js
// main.js

const worker = new Worker("static/scripts/worker.js");

worker.addEventListener("message", (event) => {
  console.error(`Received message from worker: ${event}`);
});

worker.addEventListener("messageerror", (event) => {
  console.error(`Error receiving message from worker: ${event}`);
});

The same, but using the onmessageerror event handler property (but note that this replaces other event listeners added using onmessage and onmessageerror, if any):

js
// main.js

const worker = new Worker("static/scripts/worker.js");

worker.onmessage = (event) => {
  console.error(`Received message from worker: ${event}`);
};

worker.onmessageerror = (event) => {
  console.error(`Error receiving message from worker: ${event}`);
};

Specifications

Specification
HTML
# event-messageerror

Browser compatibility

See also