MessageEvent.MessageEvent()

The MessageEvent() constructor creates a new MessageEvent object instance.

Syntax

var messageEvent = new MessageEvent(type, init);

Parameters

type

The type of MessageEvent that will be created. This can be one of XXX

init Optional

A dictionary object that can contain the following properties:

• data: The data you want contained in the MessageEvent. This can be of any data type, and will default to null if not specified.
• origin: A USVString representing the origin of the message emitter. This defaults to an empty string ("") if not specified.
• lastEventId: A DOMString representing a unique ID for the event. This defaults to an empty string ("") if not specified.
• source: An MessageEventSource (which can be a WindowProxy, MessagePort, or ServiceWorker object) representing the message emitter. This defaults to null if not set.
• ports: An array of MessagePort objects representing the ports associated with the channel the message is being sent through (where appropriate, e.g. in channel messaging or when sending a message to a shared worker). This defaults to an empty array ([]) if not specified.

Example

var myMessage = new MessageEvent('worker', {
  data : 'hello'
});

Specifications

Browser compatibility

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See also

• ExtendableMessageEvent — similar to this interface but used in interfaces that needs to give more flexibility to authors.