SharedWorkerGlobalScope: connect event
The connect
event is fired in shared workers at their SharedWorkerGlobalScope
when a new client connects.
This event is not cancelable and does not bubble.
Syntax
Use the event name in methods like addEventListener()
, or set an event handler property.
addEventListener("connect", (event) => {});
onconnect = (event) => {};
Event type
A MessageEvent
. Inherits from Event
.
Event properties
This interface also inherits properties from its parent, Event
.
MessageEvent.data
Read only-
The data sent by the message emitter.
MessageEvent.origin
Read only-
A string representing the origin of the message emitter.
MessageEvent.lastEventId
Read only-
A string representing a unique ID for the event.
MessageEvent.source
Read only-
A
MessageEventSource
(which can be a WindowProxy,MessagePort
, orServiceWorker
object) representing the message emitter. MessageEvent.ports
Read only-
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).
Examples
This example shows a shared worker file — when a connection to the worker occurs from a main thread via a MessagePort
, the onconnect
event handler fires. The event object is a MessageEvent
.
The connecting port can be referenced through the event object's ports
parameter; this reference can have an onmessage
handler attached to it to handle messages coming in through the port, and its postMessage()
method can be used to send messages back to the main thread using the worker.
self.onconnect = (e) => {
const port = e.ports[0];
port.onmessage = (e) => {
const workerResult = `Result: ${e.data[0] * e.data[1]}`;
port.postMessage(workerResult);
};
port.start();
};
For a complete running example, see our Basic shared worker example (run shared worker.)
addEventListener equivalent
You could also set up an event handler using the addEventListener()
method:
self.addEventListener("connect", (e) => {
const port = e.ports[0];
port.onmessage = (e) => {
const workerResult = `Result: ${e.data[0] * e.data[1]}`;
port.postMessage(workerResult);
};
});
Specifications
Specification |
---|
HTML Standard # event-workerglobalscope-connect |
HTML Standard # handler-sharedworkerglobalscope-onconnect |
Browser compatibility
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