Joomla 1.5 is definitely a better CMS if you compare it to Joomla 1.0. One of few complaints I have heard and personally experienced with Joomla 1.5 is the inclusion of Mootools (and caption.js) by default if you use Joomla template method to display header information in your template. What’s the problem, one may ask? Well, the problem is that the Mootools file that comes with Joomla 1.5 is whopping 74k in size. From developer’s point of view, I may never need to use mootools in my application. And from end user point of view, this really slows down initial page load times especially for users who have slower connections, and you never get a second chance to make a first impression.Mootools is definitely a very useful JavaScript framework. (And since the perfectionist founder can even FIRE his developer, that also shows it has certain standard.) But loading it without using it really irritates some people.So why the hell on earth would Joomla 1.5 includes Mootools? The reason is because Joomla 1.5 Admin section uses Mootools. It’s the C (Controller) in the MVC (Model-View-Controller) that needs it. If you have installed the latest version and seen the AJAX effects from the admin area, you may probably know what I am talking about.Now the question is how to remove the Mootools and other JavaScript files from the header when the end users see it, and keep it exists when a administrator sees it? Don’t worry, here is the solution, below is the code I use to remove the mootools.js and caption.js

<?php
$user =& JFactory::getUser();
if ($user->get('guest') == 1) {
$headerstuff = $this->getHeadData();
$headerstuff['scripts'] = array();
$this->setHeadData($headerstuff); }
?>
<jdoc:include type="head" />

In case you want to keep the caption.js, (some Joomla! components, modules or plugins uses caption.js, for example:Acajoom), you can choose to remove mootools only. Below is the PHP code i use to do so:

<?php
// Remove auto generated mootool from header
$headerstuff = $this->getHeadData();
reset($headerstuff['scripts']);
$moo = key($headerstuff['scripts']);
unset($headerstuff['scripts'][$moo]);
$this->setHeadData($headerstuff);
?>
<jdoc:include type="head">

Hope these tips help!

mysql_fetch_assoc is the native PHP MySQL function to fetch a result row as an associative array. Joomla! has it’s own database abstraction class that does this job — loadAssoc.

Below is an example of the using loadAssoc to fetch a result row from content table and show the individual selected field results:

$db = JFactory::getDBO();
$query = "SELECT * FROM #__content WHERE
title='Overview'";
$db->setQuery($query);
$article_row = $db->loadAssoc();
echo $article_row['introtext']."—".$article_row['publish_up'];

The output will the the intro text of the article with the title Overview and followed by published date and time.

Joomla is build to be able to use many different kinds of SQL-database-systems and to run in a variety of environments with different table-prefixes. In addition to these functions, the class automatically creates the database connection. Besides instantiating the object, you only need 2 lines of code to get a result from the database and that in a variety of formats. Using the Joomla database layer ensures a maximum of compatibility and flexibility for your extension.

The database class contains many methods for working with a query’s result set. One of the most useful one would be loadObjectList. The syntax of loadObjectList is: loadObjectList ( $key ), this returns an array of database objects using the current SQL query. Returns false if the query fails. If the $key parameter is set, the array is indexed using the values of the field specified by key. Otherwise, the array is indexed sequentially.

The reason I say this is a really handy function is because we always retrieves a list of results belongs to a certain category. For example, if we want to get all category titles from database jos_categories where section equals to 1, and list them out. This can be done by using the following method:

// Get a database object
$db = JFactory::getDBO();
$query = "SELECT * FROM #__categories
WHERE section = 1";
// Executes the current SQL query string.
$db->setQuery($query);
// returns the array of database objects
$list = $db->loadObjectList();
// create the list of titles
foreach ($list as $item) {
$item_title = $item->title;
echo $item_title.'<br />';
}

Joomla provides a sopisticated database abstraction layer to simplify the usage for 3PD. Joomla database class contains many methods for working with a query’s result set. Many people have encountered one problem when using getNumRows which is part of Joomla database class. The following chunk of code is the most common senario:

$db = JFactory::getDBO();
$query = "SELECT * FROM #__example2";
$db->setQuery($query);
$rows = $db->getNumRows();

When you try to execute the above chuck of code, you will get an error message similar to the one below:
Warning: mysql_num_rows(): 108 is not a valid MySQL result resource in root:\mywebsite\libraries\joomla\database\database\mysql.php on line 123

The reason that this happens is because although we called setQuery, but we’ve forgotten to call $db->query(). Add $db->query() just after $db->setQuery($query); will solve the problem. So the following chunk of code should not return any error and works fine:

$db = JFactory::getDBO();
$query = "SELECT * FROM #__example2";
$db->setQuery($query);
$db->query();
$rows = $db->getNumRows();