Worker()

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

Syntax

var myWorker = new Worker(aURL, options);

Parameters

aURL

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

options Optional

An object containing option properties that can be set when creating the object instance. Available properties are as follows:

• type: A DOMString specifying the type of worker to create. The value can be classic or module. If not specified, the default used is classic.
• credentials: A DOMString specifying the type of credentials to use for the worker. The value can be omit, same-origin, or include. If not specified, or if type is classic, the default used is omit (no credentials required).
• name: A DOMString specifying an identifying name for the DedicatedWorkerGlobalScope representing the scope of the worker, which is mainly useful for debugging purposes.

Exceptions

• A SecurityError is raised if the document is not allowed to start workers, e.g. if the URL has an invalid syntax or if the same-origin policy is violated.
• A NetworkError is raised if the MIME type of the worker script is incorrect. It should always be text/javascript (for historical reasons other JavaScript MIME types may be accepted).
• A SyntaxError is raised if aURL cannot be parsed.

Examples

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

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

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

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

Specifications

Browser compatibility

See also

The Worker interface it belongs to.