SharedWorker.constructor

The SharedWorker() constructor creates a SharedWorker object that executes the script at the specified URL. This script must obey the same-origin policy.

If the URL has an invalid syntax or if the same-origin policy is violated, a DOMException of type SECURITY_ERR is thrown.

Syntax

var myWorker = new SharedWorker(aURL, name);

Parameters

aURL

A DOMString representing the URL of the script the worker will execute. It must obey the same-origin policy.

name

An optional argument that specifies an existing SharedWorkerGlobalScope.name — if this is specified then that SharedWorkerGlobalScope will be used as the scope for this shared worker.

Return value

The created worker

Exceptions

• SecurityError is raised if the document is not allowed to start workers
• NetworkError is raised if the MIME type of one of the script is text/csv, image/*, video/*, or audio/*. It should always be text/javacript.
• SyntaxError is raised if aURL cannot be parsed.

Example

The following code snippet shows creation of a SharedWorker object using the SharedWorker() constructor and subsequent usage of the object:

var myWorker = new SharedWorker('worker.js');

myWorker.port.start();

first.onchange = function() {
  myWorker.port.postMessage([first.value,second.value]);
  console.log('Message posted to worker');
}

second.onchange = function() {
  myWorker.port.postMessage([first.value,second.value]);
  console.log('Message posted to worker');
}

myWorker.port.onmessage = function(e) {
  result1.textContent = e.data;
  console.log('Message received from worker');
}

For a full example, see our Basic shared worker example (run shared worker.)

Specifications

Specification	Status	Comment
WHATWG HTML Living Standard The definition of 'SharedWorker()' in that specification.	Living Standard	No change from Web Workers.
Web Workers The definition of 'SharedWorker()' in that specification.	Editor's Draft	Initial definition

Browser compatibility

See also

• The SharedWorker interface it belongs to.