$(active).serialize() will result in an empty string. You probably want remove the data: $(active).serialize(), line and do something like url: 'homepage/readarticle/' + encodeURIComponent(active),, depending on what your server-side application expects.
Edit:
Based on the server-side code you just added to your question, your code should work if you replace data: $(active).serialize(), with data: {active: active},.
Another Edit:
Well, I've taken the liberty to attempt to recreate your setup. And my code is working fine (as far as I've understood your intended behaviour).
The following is my CodeIgniter application. It might look like a lot of code but it's only ~120 lines in total, so bare with me. Read through it and try to run it if you can. If it doesn't help, add a comment and I can help you from there since I have the setup now.
+---controllers
| homepage.php
|
+---models
| articles.php
|
\---views
homepage.php
loadarticle.php
controllers\homepage.php:
<?php
class Homepage extends Controller {
function Homepage()
{
parent::Controller();
$this->load->model('articles');
}
function index()
{
$output = $this->articles->display_all();
$data['articles'] = $output;
$this->load->view('homepage', $data);
}
function readarticle()
{
$articlename = $this->input->post('active');
$output = $this->articles->displayby_name($articlename);
if($output){
$data['articles'] = $output;
}
$this->load->view('loadarticle', $data);
}
}
models\articles.php
<?php
class Articles extends Model {
function Articles()
{
parent::Model();
}
function display_all() {
$this->db->select("articletitle");
$this->db->from('articles');
$Q = $this->db->get();
$results = array();
if ($Q->num_rows() > 0) {
$results = $Q->result_array();
}
return $results;
}
function displayby_name($name) {
$this->db->select("articletitle, articlebody, articleauthor");
$this->db->from('articles');
$this->db->where('articletitle', $name);
$Q = $this->db->get();
if ($Q->num_rows() > 0) {
$text = $Q->result_array();
}
return $text;
}
}
views\homepage.php
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>Homepage</title>
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<style type="text/css" media="screen">
#navigation { float: left; padding: 1em; }
#loading {
display: block; position: absolute;
top: 0; left: 50%; display: none; width: 8em; margin-left: -4em;
}
#artcontent { padding: 2em; }
</style>
</head>
<body>
<ul id="navigation">
<li>
<span>Articles:</span>
<ul>
<?php foreach ($articles as $article): ?>
<li><a href="#"><?php echo $article['articletitle']; ?></a></li>
<?php endforeach; ?>
</ul>
</li>
</ul>
<span id="loading">Loading...</span>
<div id="artcontent"><p></p></div>
<script>
$('ul#navigation li ul li>a').click(function(){
var active = $(this).text();
$('#artcontent').empty();
$('#loading').show();
$.ajax({
type: 'POST',
url: 'homepage/readarticle',
data: {active: active},
success: function(databack){
$('#loading').fadeOut('normal');
$('#artcontent').append(databack);
}
});
return false;
});
</script>
</body>
</html>
views\loadarticle.php
<?php foreach ($articles as $article): ?>
<h2><?php echo $article['articletitle']; ?></h2>
by <span><?php echo $article['articleauthor']; ?></span>
<p><?php echo $article['articlebody']; ?></p>
<?php endforeach; ?>
MySQL structure and sample data
CREATE TABLE IF NOT EXISTS `articles` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`articletitle` varchar(200) NOT NULL,
`articlebody` text NOT NULL,
`articleauthor` varchar(200) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=4 ;
INSERT INTO `articles` (`id`, `articletitle`, `articlebody`, `articleauthor`)
VALUES
(1, 'foo', 'body foo body', 'author foo author'),
(2, 'bar', 'body bar body', 'author bar author'),
(3, 'baz', 'body baz body', 'author baz author');