Worker()
The Worker() constructor creates a Worker object that executes the script at the specified URL. This script must obey the same-origin policy.
Note: that there is a disagreement among browser manufacturers about whether a data URI is of the same origin or not. Though 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
new Worker(aURL, options);
Parameters
- aURL
-
A
USVStringrepresenting 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: ADOMStringspecifying 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 theDedicatedWorkerGlobalScoperepresenting the scope of the worker, which is mainly useful for debugging purposes.
Exceptions
- A
SecurityErroris 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
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 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
| Specification |
|---|
| HTML Standard # dom-worker-dev |
Browser compatibility
BCD tables only load in the browser
See also
The Worker interface it belongs to.