Joomla! Documentation™

Joomla! 

3.x

<translate> Tutorial</translate>

<translate> Developing an MVC Component</translate>

{{Chunk:Developing a Model-View-Controller (MVC) Component for Joomla!3.1 - Contents/<translate> en</translate>}} <translate> This is a multiple-article series of tutorials on how to develop a Model-View-Controller Component for Joomla! Version.</translate>

<translate> Begin with the Introduction, and navigate the articles in this series by using the navigation button at the bottom or the box to the right (the Articles in This series).</translate>

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This is a multiple-article series of tutorials on how to develop a Model-View-Contoller Component for Joomla! Version .

Creating the extension script file

Installing, updating and uninstalling a component may require additional operations that cannot be achieved by the basic operations described in the main xml file. Joomla offers a new approach to solve this problem. It consists in using a php script file containing a class using five methods:

• preflight which is executed before install and update
• install
• update
• uninstall
• postflight which is executed after install and update

Writing an extension script consists in declaring an class whose name is com_ComponentNameInstallerScript with these 5 methods. For plugins you need to add the group.

<?php
// No direct access to this file
defined('_JEXEC') or die;
 
/**
 * Script file of HelloWorld plugin
 * Group: Universe
 */
class plgUniverseHelloWorldInstallerScript
{
        /**
         * Method to install the extension
         * $parent is the class calling this method
         *
         * @return void
         */
        function install($parent) 
        {
                echo '<p>The module has been installed</p>';
        }
 
        /**
         * Method to uninstall the extension
         * $parent is the class calling this method
         *
         * @return void
         */
        function uninstall($parent) 
        {
                echo '<p>The module has been uninstalled</p>';
        }
 
        /**
         * Method to update the extension
         * $parent is the class calling this method
         *
         * @return void
         */
        function update($parent) 
        {
                echo '<p>The module has been updated to version' . $parent->get('manifest')->version) . '</p>';
        }
 
        /**
         * Method to run before an install/update/uninstall method
         * $parent is the class calling this method
         * $type is the type of change (install, update or discover_install)
         *
         * @return void
         */
        function preflight($type, $parent) 
        {
                echo '<p>Anything here happens before the installation/update/uninstallation of the module</p>';
        }
 
        /**
         * Method to run after an install/update/uninstall method
         * $parent is the class calling this method
         * $type is the type of change (install, update or discover_install)
         *
         * @return void
         */
        function postflight($type, $parent) 
        {
                echo '<p>Anything here happens after the installation/update/uninstallation of the module</p>';
        }
}