Note: This feature is only available in Service Workers.
The ExtendableMessageEvent() constructor creates a new ExtendableMessageEvent object.
new ExtendableMessageEvent(type)
new ExtendableMessageEvent(type, options)typeA string with the name of the event. It is case-sensitive and browsers set it to messageerror or message.
options OptionalAn object that, in addition of the properties defined in ExtendableEvent(), can have the following properties:
data OptionalThe event's data; this can be any data type. It defaults to null.
origin OptionalA string that defines the origin of the corresponding service worker's environment settings object. It defaults to "".
lastEventId OptionalA string that defines the last event ID of the event source. It defaults to "".
source OptionalThe Client, ServiceWorker or MessagePort that sent the message. It defaults to null.
ports OptionalAn array containing the MessagePort objects connected to the channel sending the message. It defaults to an empty array.
A new ExtendableMessageEvent object.
const options = {
data: "hello message",
source: MessagePortReference,
ports: MessagePortListReference,
};
const myEME = new ExtendableMessageEvent("message", init);