<?php  // No direct access to this file  defined('_JEXEC') or die('Restricted access');     // import Joomla modelitem library  jimport('joomla.application.component.modelitem');     /**   * HelloWorld Model   */  class HelloWorldModelHelloWorld extends JModelItem  {  	/**  	 * @var string msg  	 */  	protected $msg;     	/**  	 * Get the message  	 * @return string The message to be displayed to the user  	 */  	public function getMsg()   	{  		if (!isset($this->msg))   		{  			$this->msg = 'Hello World!';  		}  		return $this->msg;  	}  }  

<?php  // No direct access to this file  defined('_JEXEC') or die('Restricted access');     // import Joomla view library  jimport('joomla.application.component.view');     /**   * HTML View class for the HelloWorld Component   */  class HelloWorldViewHelloWorld extends JView  {  	// Overwriting JView display method  	function display($tpl = null)   	{  		// Assign data to the view  		$this->msg = $this->get('Msg');     		// Check for errors.  		if (count($errors = $this->get('Errors')))   		{  			JError::raiseError(500, implode('<br />', $errors));  			return false;  		}  		// Display the view  		parent::display($tpl);  	}  }  

<?xml version="1.0" encoding="utf-8"?>  <extension type="component" version="1.6.0" method="upgrade">     	<name>Hello World!</name>  	<!-- The following elements are optional and free of formatting conttraints -->  	<creationDate>November 2009</creationDate>  	<author>John Doe</author>  	<authorEmail>[email protected]</authorEmail>  	<authorUrl>http://www.example.org</authorUrl>  	<copyright>Copyright Info</copyright>  	<license>License Info</license>  	<!--  The version string is recorded in the components table -->  	<version>0.0.4</version>  	<!-- The description is optional and defaults to the name -->  	<description>Description of the Hello World component ...</description>     	<update> <!-- Runs on update; New in 1.6 -->  		<schemas>  			<schemapath type="mysql">sql/updates/mysql</schemapath>  		</schemas>  	</update>     	<!-- Site Main File Copy Section -->  	<!-- Note the folder attribute: This attribute describes the folder  		to copy FROM in the package to install therefore files copied  		in this section are copied from /site/ in the package -->  	<files folder="site">  		<filename>index.html</filename>  		<filename>helloworld.php</filename>  		<filename>controller.php</filename>  		<folder>views</folder>  		<folder>models</folder>  	</files>     	<administration>  		<!-- Administration Menu Section -->  		<menu>Hello World!</menu>  		<!-- Administration Main File Copy Section -->  		<!-- Note the folder attribute: This attribute describes the folder  			to copy FROM in the package to install therefore files copied  			in this section are copied from /admin/ in the package -->  		<files folder="admin">  			<!-- Admin Main File Copy Section -->  			<filename>index.html</filename>  			<filename>helloworld.php</filename>  			<!-- SQL files section -->  			<folder>sql</folder>  		</files>  	</administration>     </extension>