User Guide

Example: Detecting system capabilities 447
Communicating with JavaScript
The final piece in building the CapabilitiesExplorer application is writing the necessary
JavaScript to loop over each of the items in the browser’s navigator object and append a name-
value pair to a temporary array. The code for the JavaScript
JS_getBrowserObjects()
method in the container.html file is as follows:
<script language="JavaScript">
function JS_getBrowserObjects()
{
// Create an array to hold each of the browser's items.
var tempArr = new Array();
// Loop over each item in the browser's navigator object.
for (var name in navigator)
{
var value = navigator[name];
// If the current value is a string or Boolean object, add it to the
// array, otherwise ignore the item.
switch (typeof(value))
{
case "string":
case "boolean":
// Create a temporary string which will be added to the array.
// Make sure that we URL-encode the values using JavaScript's
// escape() function.
var tempStr = "navigator." + name + "=" + escape(value);
// Push the URL-encoded name/value pair onto the array.
tempArr.push(tempStr);
break;
}
}
// Loop over each item in the browser's screen object.
for (var name in screen)
{
var value = screen[name];
// If the current value is a number, add it to the array, otherwise
// ignore the item.
switch (typeof(value))
{
case "number":
var tempStr = "screen." + name + "=" + escape(value);
tempArr.push(tempStr);
break;
}
}
// Return the array as a URL-encoded string of name-value pairs.