J3.x

J3.x:Developing an MVC Component/Adding an install-uninstall-update script file

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3.x
Tutorial
Developing an MVC Component



This is a multiple-article series of tutorials on how to develop a Model-View-Controller Component for Joomla! VersionJoomla 3.x.

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).



Introduction

This tutorial is part of the Developing an MVC Component for Joomla! 3.2 tutorial. You are encouraged to read the previous parts of the tutorial before reading this.

You can watch a video associated with this step at Outline of Joomla Install Process.

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

Write an extension script by declaring a class whose name is com_ComponentNameInstallerScript with these five methods.

script.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');

/**
 * Script file of HelloWorld component.
 *
 * The name of this class is dependent on the component being installed.
 * The class name should have the component's name, directly followed by
 * the text InstallerScript (ex:. com_helloWorldInstallerScript).
 *
 * This class will be called by Joomla!'s installer, if specified in your component's
 * manifest file, and is used for custom automation actions in its installation process.
 *
 * In order to use this automation script, you should reference it in your component's
 * manifest file as follows:
 * <scriptfile>script.php</scriptfile>
 *
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */
class com_helloWorldInstallerScript
{
    /**
     * This method is called after a component is installed.
     *
     * @param  \stdClass $parent - Parent object calling this method.
     *
     * @return void
     */
    public function install($parent) 
    {
        $parent->getParent()->setRedirectURL('index.php?option=com_helloworld');
    }

    /**
     * This method is called after a component is uninstalled.
     *
     * @param  \stdClass $parent - Parent object calling this method.
     *
     * @return void
     */
    public function uninstall($parent) 
    {
        echo '<p>' . JText::_('COM_HELLOWORLD_UNINSTALL_TEXT') . '</p>';
    }

    /**
     * This method is called after a component is updated.
     *
     * @param  \stdClass $parent - Parent object calling object.
     *
     * @return void
     */
    public function update($parent) 
    {
        echo '<p>' . JText::sprintf('COM_HELLOWORLD_UPDATE_TEXT', $parent->get('manifest')->version) . '</p>';
    }

    /**
     * Runs just before any installation action is performed on the component.
     * Verifications and pre-requisites should run in this function.
     *
     * @param  string    $type   - Type of PreFlight action. Possible values are:
     *                           - * install
     *                           - * update
     *                           - * discover_install
     * @param  \stdClass $parent - Parent object calling object.
     *
     * @return void
     */
    public function preflight($type, $parent) 
    {
        echo '<p>' . JText::_('COM_HELLOWORLD_PREFLIGHT_' . $type . '_TEXT') . '</p>';
    }

    /**
     * Runs right after any installation action is performed on the component.
     *
     * @param  string    $type   - Type of PostFlight action. Possible values are:
     *                           - * install
     *                           - * update
     *                           - * discover_install
     * @param  \stdClass $parent - Parent object calling object.
     *
     * @return void
     */
    function postflight($type, $parent) 
    {
        echo '<p>' . JText::_('COM_HELLOWORLD_POSTFLIGHT_' . $type . '_TEXT') . '</p>';
    }
}

This script file will redirect the user to the com_helloworld component when it is installed and will display messages when it is updated or uninstalled. In the update method we show the new version using $parent->get('manifest')->version.

Adding Some Language Keys

admin/language/en-GB/en-GB.com_helloworld.sys.ini

; Joomla! Project
; Copyright (C) 2005 - 2018 Open Source Matters. All rights reserved.
; License GNU General Public License version 2 or later; see LICENSE.txt, see LICENSE.php
; Note : All ini files need to be saved as UTF-8

COM_HELLOWORLD="Hello World!"
COM_HELLOWORLD_DESCRIPTION="This is the Hello World description"
COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_TITLE="Hello World"
COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_DESC="This view displays a selected message"
COM_HELLOWORLD_INSTALL_TEXT="HelloWorld Install script"
COM_HELLOWORLD_MENU="Hello World!"
COM_HELLOWORLD_POSTFLIGHT_DISCOVER_INSTALL_TEXT="HelloWorld postflight discover install script"
COM_HELLOWORLD_POSTFLIGHT_INSTALL_TEXT="HelloWorld postflight install script"
COM_HELLOWORLD_POSTFLIGHT_UNINSTALL_TEXT="HelloWorld postflight uninstall script"
COM_HELLOWORLD_POSTFLIGHT_UPDATE_TEXT="HelloWorld postflight update script"
COM_HELLOWORLD_PREFLIGHT_DISCOVER_INSTALL_TEXT="HelloWorld preflight discover install script"
COM_HELLOWORLD_PREFLIGHT_INSTALL_TEXT="HelloWorld preflight install script"
COM_HELLOWORLD_PREFLIGHT_UNINSTALL_TEXT="HelloWorld preflight uninstall script"
COM_HELLOWORLD_PREFLIGHT_UPDATE_TEXT="HelloWorld preflight update script"
COM_HELLOWORLD_UNINSTALL_TEXT="HelloWorld Uninstall script"
COM_HELLOWORLD_UPDATE_TEXT="HelloWorld Update script. HelloWorld now updated to version %s."

Note If you want these languages KEYs to be used at the first install of the component, the .sys.ini language file must be stored in the component folder (admin/language/en-GB/en-GB.com_helloworld.sys.ini), and the .xml manifest file must contains a folder tag for copying language into the component folder. Modify your manifest file accordingly:

                <files folder="admin">
                        <!-- language folder -->
                        <folder>language</folder>
                </files>
 
                <languages folder="admin">
                        <language tag="en-GB">language/en-GB/en-GB.com_helloworld.ini</language>
                        <!-- com_helloworld.sys.ini no longer needed there-->
                </languages>

Packaging the Component

Content of your code directory. Each file link below takes you to the step in the tutorial which has the latest version of that source code file.

Create a compressed file of this directory or directly download the archive and install it using the extension manager of Joomla. You can add a menu item of this component using the menu manager in the backend.

helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="component" version="3.0" method="upgrade">

	<name>COM_HELLOWORLD</name>
	<!-- The following elements are optional and free of formatting constraints. -->
	<creationDate>January 2018</creationDate>
	<author>John Doe</author>
	<authorEmail>john.doe@example.org</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>0.0.15</version>
	<!-- The description is optional and defaults to the name -->
	<description>COM_HELLOWORLD_DESCRIPTION</description>

	<!-- Runs on install/uninstall/update; New in 2.5 -->
	<scriptfile>script.php</scriptfile>

	<install> <!-- Runs on install -->
		<sql>
			<file driver="mysql" charset="utf8">sql/install.mysql.utf8.sql</file>
		</sql>
	</install>
	<uninstall> <!-- Runs on uninstall -->
		<sql>
			<file driver="mysql" charset="utf8">sql/uninstall.mysql.utf8.sql</file>
		</sql>
	</uninstall>
	<update> <!-- Runs on update; New since J2.5 -->
		<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>

        <languages folder="site/language">
		<language tag="en-GB">en-GB/en-GB.com_helloworld.ini</language>
        </languages>

	<media destination="com_helloworld" folder="media">
		<filename>index.html</filename>
		<folder>images</folder>
	</media>

	<administration>
		<!-- Administration Menu Section -->
		<menu link='index.php?option=com_helloworld' img="../media/com_helloworld/images/tux-16x16.png">COM_HELLOWORLD_MENU</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>config.xml</filename>
			<filename>helloworld.php</filename>
			<filename>controller.php</filename>
			<filename>access.xml</filename>
			<!-- SQL files section -->
			<folder>sql</folder>
			<!-- tables files section -->
			<folder>tables</folder>
			<!-- models files section -->
			<folder>models</folder>
			<!-- views files section -->
			<folder>views</folder>
			<!-- controllers files section -->
			<folder>controllers</folder>
			<!-- helpers files section -->
			<folder>helpers</folder>
		</files>
		<languages folder="admin/language">
        		<language tag="en-GB">en-GB/en-GB.com_helloworld.ini</language>
                        <language tag="en-GB">en-GB/en-GB.com_helloworld.sys.ini</language>
		</languages>
	</administration>

</extension>

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