Archived:Developing a MVC Component/Developing a Basic Component

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Articles in this Series

1. Introduction
2. Developing a Basic Component
3. Adding a view to the site part
4. Adding a menu type to the site part
5. Adding a model to the site part
6. Adding a variable request in the menu type
7. Using the database
8. Basic backend
9. Adding language management
10. Adding backend actions
11. Adding decorations to the backend
12. Adding verifications
13. Adding categories
14. Adding configuration
15. Adding ACL
16. Adding an install/uninstall/update script file
17. Using the language filter facility
18. Adding an update server
19. Example of a Frontend Update Function
20. Example of Menu Parameters & Stylesheets

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

Before heading out and start

It is recommended watching these 2 basics videos. They last for about 2 hours total, and cover some things with more patience and obviously visual support. So first get to know things with these videos, then go ahead and play around yourself with the help of this tutorial:

http://www.youtube.com/watch?v=kUTH2DKmjhI

http://www.youtube.com/watch?v=5Q_a5g3gEMM

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.

Note: <name>Hello World!</name> is tricking you into thinking that this is actually only a name, and you could call it 'fluffy' or 'bippo', but this is not true. As far as I understand the name in between the tags is getting automagically lowercased, white spaces and special characters are removed (the ! for example) and joomla starts to look for files/folders responding to this name. So the name you are giving there is actually very crucial for your component to work. In other words, if you would change "Hello World!" to "helloworld" everyhting would still work. If you would change it to "helloworld2" the component would be looking for different folders and file names.

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>

Navigate

Next: Adding a view to the site part

Contributors

• Christophe Demko
• Ozgur Aksu