JElement и потомки. Для чего и как использовать? - Модификации расширений для Joomla

<?xml version="1.0" encoding="utf-8"?>
<metadata>
	<layout title="Elements">
		<message>
			<![CDATA[This shows elements]]>
		</message>
	</layout>
	<state>
		<name>MyComponent parameters</name>
		<description>Select elements from dropdown</description>
		<url addpath="/administrator/components/COMPONENT_NAME/elements">
			<param name="paramid" type="blablabla" label="Element" description="Choose element..." />
		</url>
	</state>
</metadata>

class JElementblablabla extends JElement {
	/**
	 * Element name
	 *
	 * @access	protected
	 * @var		string
	 */
	var $_name = 'paramid';
	
	function fetchElement($name, $value, &$node, $control_name) {
		$db = &JFactory::getDBO ();
		$query = ' SELECT id, text FROM sometable';

		$db->setQuery ( $query );
		$options = $db->loadObjectList ();
		
		return JHTML::_ ( 'select.genericlist', $options, '' . $control_name . '[' . $name . ']', 'class="inputbox"', 'id', 'text', $value, $control_name . $name );
	}
}