j2.5 : 1. The first basic component

Introduction

This tutorial is part of the Developing a Model-View-Controller (MVC) Component for Joomla!2.5 tutorial.

The first basic component

Let's create a Hello World! component.

Public display

With your favorite file manager and editor, create a file yoursite/components/com_helloworld/helloworld.php containing

Hello world

You can test this basic component by putting index.php?option=com_helloworld in your browser address (don't forget to prefix this address with your Joomla!2.5 installation path) after installing this component.

Administrator management

With your favorite file manager and editor, create a file yoursite/administrator/components/com_helloworld/helloworld.php containing

Hello world administration

You can test this basic component by putting administrator/index.php?option=com_helloworld in your browser address after installing the component.

Packaging an installation zip file

If you have used Joomla before reading this tutorial, you have noticed that extensions are installed using a compressed file containing all the things which are needed for installing and uninstalling them.
With your favorite file manager, create a directory (outside your Joomla installation directory) containing

• helloworld.xml
• site/helloworld.php
• site/index.html
• admin/index.html
• admin/helloworld.php
• admin/sql/index.html
• admin/sql/updates/index.html
• admin/sql/updates/mysql/index.html
• admin/sql/updates/mysql/0.0.1.sql

admin/sql/updates/mysql/0.0.1.sql is an empty file allowing to initialise schema version of the com_helloworld component.
admin/sql/updates/mysql/0.0.1.sql

Create a compressed file of this directory or directly download the archive and install it using the extension manager of Joomla. You can test this basic component by putting index.php?option=com_helloworld or administrator/index.php?option=com_helloworld in your browser address. You can also notice that the Hello World! component is visible in the administrator site of your Joomla installation under the Components menu.
helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="component" version="2.5.0" method="upgrade">
 
        <name>Hello World!</name>
        <!-- The following elements are optional and free of formatting constraints -->
        <creationDate>November 2009</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>0.0.1</version>
        <!-- The description is optional and defaults to the name -->
        <description>Description of the Hello World component ...</description>
 
        <update> <!-- Runs on update; New in 2.5 -->
                <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>
        </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>

site/helloworld.php

Hello World

admin/helloworld.php

Hello World administration

index.html common to all folders

<html><body bgcolor="#FFFFFF"></body></html>