SharedWorkerGlobalScope: connect event

The connect event is fired in shared workers at their SharedWorkerGlobalScope when a new client connects.

Bubbles No
Cancelable No
Interface MessageEvent
Event handler property SharedWorkerGlobalScope.onconnect

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 = function(e) {
    var port = e.ports[0];

    port.onmessage = function(e) {
      var 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', function(e) {
  var port = e.ports[0];

  port.onmessage = function(e) {
    var workerResult = 'Result: ' + (e.data[0] * e.data[1]);
    port.postMessage(workerResult);
  }

});

Specifications

Specification Status
HTML Living Standard
The definition of 'connect event' in that specification.
Living Standard

Browser compatibility

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See also