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function loadUrl( url ) { ... }
function getMore()
{
var url = window.location.toString();
url = url.replace( /pat1_readmore.html/, ‘pat1_readmore_content.html’ );
loadUrl( url );
}
</script>
<body>
<h1>Walking the dog</h1>
I took my dog for a walk today.
<span id=”moreSpan”>
<a href=”javascript: void getMore()”>Read more...</a>
</span>
</body>
</html>
Listing 7 shows the content for the “read more” section.
Listing 7. Pat1_readmore_content.html
It was a nice day out. Warm and sunny. My dog liked getting out for a stretch.
This code demonstrates the use of the <span> tag instead of the <div> tag. The approach you
use depends on the requirements of your user interface (UI). But as you can see, it’s easy to use
either approach.
Getting new HTML for the page is one thing, but what about when you want the JavaScript code on
the page to actually do something intelligent with the data. How do you get the data to the browser
in a structured way? Why XML, of course.
Pattern 2. Reading XML data
For some reason, Ajax has become synonymous with XML, even though XML isn’t strictly required.
As you can see from the examples above, you can return straight text or even fragments of HTML — or Extensible HTML (XHTML) — code. But sending XML can have its rewards.
Listing 8 shows Ajax code that requests records about books from the server, then displays that
data in a table within the page.
Listing 8. Pat2_xml.html
<html>
<head>
<script>
var req = null;
function processReqChange() {
if (req.readyState == 4 && req.status == 200 && req.responseXML ) {
var dtable = document.getElementById( ‘dataBody’ );
var nl = req.responseXML.getElementsByTagName( ‘book’ );
for( var i = 0; i < nl.length; i++ ) { |
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Apr 2008 | Java Jazz Up | 68 |
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