DedicatedWorkerGlobalScope: message event

The message event is fired on a DedicatedWorkerGlobalScope object when the worker receives a message from its parent (i.e. when the parent sends a message using Worker.postMessage()).

Examples

This code creates a new worker and sends it a message using Worker.postMessage():

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

worker.addEventListener('message', (event) => {
    console.log(`Received message from worker: ${event.data}`)
});

The worker can listen for this message using addEventListener():

// inside static/scripts/worker.js

self.addEventListener('message', (event) => {
    console.log(`Received message from parent: ${event.data}`);  
});

Alternatively, it could listen using the onmessage event handler property:

// static/scripts/worker.js

self.onmessage = (event) => {
    console.log(`Received message from parent: ${event.data}`);  
};

Specifications

Browser compatibility

See also

• Related events: messageerror.
• Worker.postMessage().