Joomla! Documentation™

Joomla! 

3.x

Tutorial

Developing an MVC Component

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. Adding a Frontend Form
18. Adding an Image
19. Adding a Map
20. Adding AJAX
21. Adding an Alias
22. Using the Language Filter Facility
23. Adding a Modal
24. Adding Associations
25. Adding Checkout
26. Adding Ordering
27. Adding Levels
28. Adding Versioning
29. Adding Tags
30. Adding Access
31. Adding a Batch Process
32. Adding Cache
33. Adding a Feed
34. Adding an Update Server
35. Adding Custom Fields
36. Upgrading to Joomla4

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

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).

Notes

This tutorial is part of the Developing a MVC Component for Joomla! 3.x tutorial. You are encouraged to read the previous parts of the tutorial before reading this.

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.

You can follow the steps below to create the Hello World! component, or you can directly download files from the git repository archive

Here are some slides based on this documents to explain how to create basic to advance Joomla! components.
Joomla! Basic Component Help
Joomla! Advance Component Help

There are also a number of videos which accompany steps in the tutorial, beginning with
Step 1, Developing a Basic Component and you can access the slides which are used in the series of video presentations at Slides.

Important! Around version 3.8 the Joomla developers started changing the naming of Joomla classes and where they were stored in the directory structure. Many of the tutorial steps and videos refer to the old naming convention. To find the equivalent new class and where it's stored, look in your libraries/classmap.php file.

How to add a component to Joomla!

In this article we will cover how to create and install a basic Joomla! component. For this example we will be working with the Hello World! component.

To begin, you must first use your preferred file manager to create a directory for the Hello World! component. This directory can be anywhere on your file system, as long as it is outside of your Joomla! installation directory. For this example we will name the directory com_helloworld, but this directory can be named anything.

Next, inside this directory we need to create some files. Using your preferred file manager, create the following files; as you create the files, add the source code for each file which is found in File Details.

1	helloworld.xml	this is an XML (manifest) file that tells Joomla! how to install our component.
2	site/helloworld.php	this is the site entry point to the Hello World! component
3	site/index.html	prevents web server from listing directory content
4	admin/index.html	prevents web server from listing directory content
5	admin/helloworld.php	this is the administrator entry point to the Hello World! component
6	admin/sql/index.html	prevents web server from listing directory content
7	admin/sql/updates/index.html	prevents web server from listing directory content
8	admin/sql/updates/mysql/index.html	prevents web server from listing directory content
9	admin/sql/updates/mysql/0.0.1.sql	file allowing to initialise schema version of the com_helloworld component.

Installing the Hello World! Component

Using your preferred file manager, create a .zip file of this directory. For this example we will name the file com_helloworld.zip, again this file could have been named anything.

Now we need to install the Hello World! component. There are two ways to do this, both are covered in Installing an Extension. Here we will cover the method using the Extension Manager of Joomla!.

• Using your preferred web browser, navigate to the Administrator panel of your Joomla! site. The address would be <yoursite>/joomla/administrator/index.php. For this example we will navigate to localhost/joomla/administrator/index.php.
• Click Extensions  →  Manage  →  Install  →  Upload Package File  →  Choose File
• Navigate and Select File
• Click Upload & Install

Note - You should see a message letting you know if the installation succeeded or failed.

You can test this basic function of the component by entering the Hello World! page for the site and administrator portions of your Joomla! website.

• Using your preferred web browser, navigate to the Hello World! component page located on the site portion of your website. The address would be <yoursite>/joomla/index.php?option=com_helloworld. For this example we will navigate to localhost/joomla/index.php?option=com_helloworld.
• Using your preferred web browser, navigate to the Hello World! component page located on the administrator portion of your website. The address would be <yoursite>/joomla/administrator/index.php?option=com_helloworld. For this example we will navigate to localhost/joomla/administrator/index.php?option=com_helloworld.

You can also notice that the Hello World! component is visible in the administrator site of your Joomla installation under the Components menu.

File Details

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

helloworld.xml

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

	<name>Hello World!</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>0.0.1</version>
	<!-- The description is optional and defaults to the name -->
	<description>Description of the Hello World component ...</description>

	<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>
	</files>

	<administration>
		<!-- Administration Menu Section -->
		<menu link='index.php?option=com_helloworld'>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>

Component Contents

At this point in the tutorial, your component should contain the following files:

1	helloworld.xml	this is an XML (manifest) file that tells Joomla! how to install our component.
2	site/helloworld.php	this is the site entry point to the Hello World! component
3	site/index.html	prevents web server from listing directory content
4	admin/index.html	prevents web server from listing directory content
5	admin/helloworld.php	this is the administrator entry point to the Hello World! component
6	admin/sql/index.html	prevents web server from listing directory content
7	admin/sql/updates/index.html	prevents web server from listing directory content
8	admin/sql/updates/mysql/index.html	prevents web server from listing directory content
9	admin/sql/updates/mysql/0.0.1.sql	file allowing to initialise schema version of the com_helloworld component.

General Information

Prev: Introduction

Next: Adding a view to the site part