A Simple Example Worker

This example demonstrates how to create a simple worker that can be started and stopped with buttons. Note that this code requires a web server to run, due to browser security restrictions.

ExampleWorker.html

<!DOCTYPE html>
<html>
  <head>
    <title>XoaX.net's JavaScript: An Example Worker</title>
    <script type="text/javascript">
var qWorker = null;

function Play() {
	if (qWorker == null) {
		qWorker = new Worker("WorkerScript.js");
		qWorker.onmessage = function(qEvent) {
			document.getElementById("idSign").innerHTML = qEvent.data;
		}
	}
}

function Pause() {
	if (qWorker != null) {
		qWorker.terminate();
		qWorker = null;
	}
}
    </script>
  </head>
  <body>
  	<button onclick="Play()">Play</button>
  	<button onclick="Pause()">Pause</button>
  	<h1 id="idSign">Nothing</h1>
  </body>
</html>

WorkerScript.js

var saSigns = ["Stop", "Go", "Caution", "Yield", "Halt", "Walk"];
var iIndex = 0;

function ChangeSign() {
  iIndex = ((iIndex + 1) % saSigns.length);
  postMessage(saSigns[iIndex]);
  setTimeout("ChangeSign()",500);
}

ChangeSign();

Core JavaScript

A Simple Example Worker

ExampleWorker.html

WorkerScript.js

Output