ServiceWorkerGlobalScope: messageerror event

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is only available in Service Workers.

The messageerror event of the ServiceWorkerGlobalScope interface occurs when incoming messages can't be deserialized.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

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

onmessageerror = (event) => { }

Event type

An ExtendableMessageEvent. Inherits from ExtendableEvent.

EventExtendableEventExtendableMessageEvent

Examples

In the below example a page gets a handle to the ServiceWorker object via ServiceWorkerRegistration.active, and then calls its postMessage() function.

js
// main.js
if (navigator.serviceWorker) {
  navigator.serviceWorker.register("service-worker.js");

  navigator.serviceWorker.addEventListener("message", (event) => {
    // event is a MessageEvent object
    console.log(`The service worker sent me a message: ${event.data}`);
  });

  navigator.serviceWorker.ready.then((registration) => {
    registration.active.postMessage("Hi service worker");
  });
}

The service worker can listen for the message deserialization error by listening to the messageerror event:

js
// service-worker.js
self.addEventListener("messageerror", (event) => {
  // event is an ExtendableMessageEvent object
  console.error("Message deserialization failed");
});

Alternatively, the script can listen for the message deserialization error using onmessageerror:

js
// service-worker.js
self.onmessageerror = (event) => {
  // event is an ExtendableMessageEvent object
  console.error("Message deserialization failed");
};

Specifications

See also