The SharedWorker() constructor creates a SharedWorker object that executes the script at the specified URL. This script must obey the same-origin policy.
Note: there is disagreement among browser manufacturers about whether a data URI is of the same origin or not. Although Gecko 10.0 (Firefox 10.0 / Thunderbird 10.0 / SeaMonkey 2.7) and later accept data URIs, that's not the case in all other browsers.
Syntax
var myWorker = new SharedWorker(aURL, name); var myWorker = new SharedWorker(aURL, options);
Parameters
- aURL
- A
DOMStringrepresenting the URL of the script the worker will execute. It must obey the same-origin policy. - name Optional
- A
DOMStringspecifying an identifying name for theSharedWorkerGlobalScoperepresenting the scope of the worker, which is mainly useful for debugging purposes. - options Optional
- An object containing option properties that can set when creating the object instance. Available properties are as follows:
type- A
DOMStringspecifying the type of worker to create. The value can beclassicormodule. If not specified, the default used isclassic. credentials: ADOMStringspecifying the type of credentials to use for the worker. The value can beomit,same-origin, orinclude. If not specified, or if type isclassic, the default used isomit(no credentials required).name: ADOMStringspecifying an identifying name for theSharedWorkerGlobalScoperepresenting the scope of the worker, which is mainly useful for debugging purposes.
- A
Return value
The created worker.
Exceptions
- A
SecurityErroris raised if the document is not allowed to start workers, for example if the URL has an invalid syntax or if the same-origin policy is violated. - A
NetworkErroris raised if the MIME type of the worker script is incorrect. It should always betext/javascript(for historical reasons other JavaScript MIME types may be accepted). - A
SyntaxErroris raised if aURL cannot be parsed.
Examples
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 ([[../../../../../../../mdn.github.io/simple-shared-worker/index|run shared worker]].)
Specifications
| Specification | Status | Comment |
| HTML Living StandardThe definition of 'SharedWorker()' in that specification. | Living Standard |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
See also
- The
SharedWorkerinterface it belongs to. - another multiply demo
SharedWorker() by Mozilla Contributors is licensed under CC-BY-SA 2.5.
