ServiceWorkerMessageEvent.source

The source read-only property of the ServiceWorkerMessageEvent returns a reference to the ServiceWorker object of the associated service worker that sent the message.

Syntax

var mySource = ServiceWorkerMessageEventInstance.source;

Value

A ServiceWorker or MessagePort object.

Examples

When the following code is used inside the main thread to set up a message channel between it and a service worker for sending messages between the two, the event object of onmessage will be a ServiceWorkerMessageEvent.

navigator.serviceWorker.ready.then(function(reg) {  

  ...

      // set up a message channel to communicate with the SW
      var channel = new MessageChannel();
      channel.port1.onmessage = function(e) {
        console.log(e.source);
        handleChannelMessage(e.data);
      }
      
      mySW = reg.active;
      mySW.postMessage('hello', [channel.port2]);
  });

Specifications

Specification	Status	Comment
Service Workers The definition of 'ServiceWorkerMessageEvent.source' in that specification.	Working Draft	Initial definition.

Browser compatibility

[1] Service workers (and Push) have been disabled in the Firefox 45 Extended Support Release (ESR.)

See also

• Using Service Workers
• Service workers basic code example
• Is ServiceWorker ready?
• Channel Messaging