There are all these AJAX libraries out there that help you add it to web apps, and that is great. However I am never one to use something without tearing off the hood and having a good look. So I decided that I wanted to make a simple webpage that updated itself with out a page reload. I figured that would be enough to put curiosity to rest on the subject. When you strip it all down, it’s not that hard to understand.
Some simple HTML:
Some simple JavaScript:
requestObject = new XMLHttpRequest();
function sendRequest() {
requestObject.open('get', 'http://localhost/cgi-bin/ajax.pl');
requestObject.onreadystatechange = handleResponse;
requestObject.send(null);
}
function handleResponse() {
if(requestObject.readyState == 4){
response = requestObject.responseText;
document.getElementById('thatDiv').innerHTML = response;
}
}
And a smattering of perl:
#!/usr/bin/perl -w
use strict;
use CGI;
my $q = new CGI;
my $text = $q->header();
$text .= "See I told you it was easy";
print $text;
…and well that is about it.
