ServiceWorkerMessageEvent

The ServiceWorkerMessageEvent interface of the ServiceWorker API contains information about an event sent to a ServiceWorkerContainer target. This extends the default message event to allow setting a ServiceWorker object as the source of a message. The event object is accessed via the handler function of a message event, when fired by a message received from a service worker.

This interface inherits from the Event interface.

Constructor

ServiceWorkerMessageEvent.ServiceWorkerMessageEvent()

Creates a new ServiceWorkerMessageEvent object instance.

Properties

Inherits properties from its parent, Event.

ServiceWorkerMessageEvent.data Read only

Returns the event's data. It can be any data type.

ServiceWorkerMessageEvent.origin Read only

Returns the origin of the service worker's environment settings object.

ServiceWorkerMessageEvent.lastEventId Read only

Represents, in server-sent events, the last event ID of the event source.

ServiceWorkerMessageEvent.source Read only

Returns a reference to the service worker that sent the message.

ServiceWorkerMessageEvent.ports Read only

Returns an array of MessagePort objects.

Methods

Inherits methods from its parent, Event.

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);
        handleChannelMessage(e.data);
      }
      
      mySW = reg.active;
      mySW.postMessage('hello', [channel.port2]);
  });

Specifications

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?
• Using web workers