Joomla! Documentation™

The development of Joomla! itself is carried out by the Production Department and third party developers. This page is a starting point for developers interested in the development of components, modules, plugins and templates.

Have an Interest in Core Contributions?

Getting Started!

There are several ways of setting up your workstation in for Joomla! development. Some suggestions can be found at Setting up your workstation for Joomla development.

Next, you should familiarise yourself with Joomla! Secure coding guidelines and the short article on Joomla! Development Best Practices.

Documentation on the Joomla! API can assist with becoming familiar with the foundations of the Joomla! code base.

Finally, Joomla! has many resources for developers. Our Joomla! Resources page will get you pointed in the right direction if you need help and solutions.

There is four types of extensions development:

Components

There are many articles, tutorials, references and FAQs which focus on component development. If this is your first time developing a component for Joomla, you should start with the Absolute Basics of How a Component Functions. If needed, you can visualise the control flow of a component with these diagrams.

Next, you will want to read our   MVC tutorial  →  Developing a Model-View-Controller Component. Remember to familiarise yourself with Joomla! Secure coding guidelines and Development Best Practices.

Once you have read the tutorial and/or tried the example component, you can focus more on the specifics of your component with additional articles. These are listed on the Component Development Portal or any of the supporting Portals for Development(Plugins, Modules or Templates).

For more articles and information:

Plugins

The following articles will help familiarise you with Joomla! plugins. They are a good starting point to understanding and then developing plugins.

Beginner

To understand how to install and use a plugin in Joomla it is recommended to read Administration of a Plugin in Joomla!

Intermediate

To understand plugins better it is advised that you create a basic plugin for Joomla!.

To read on how to run a basic content plugin in a custom module or component you may have already developed it is recommended to read Triggering content plugins in your extension.

Advanced

To understand the principles on which the Plugin system works Plugin Developer Overview. To then implement this in a component you have designed it is recommended to read Supporting plugins in your component.

For more articles and information:

Modules

• Creating a simple module for Joomla
• Extensions name

For more articles and information:

Templates

Our template development documentation contains many articles, FAQs and tutorials. A first step to developing a template is understanding how templates are executed.

Beginners

• Changing the site favicon
• Using Firebug With Your Joomla Website
• Using Joomla's Default Icomoon Fonts

Intermediate

• jdoc statements
• How to cloak email addresses  
• Understanding Output Overrides  
• Layout Overrides in Joomla!  
• Creating clickable background images using CSS
• Using Class Suffixes

For more articles and information:

More Development Topics

Database

• Accessing the database using JDatabase
• Using the JTable class
• Connecting to an external database
• Using nested sets

Localisation

• Language Guidelines for 3rd Party Extensions
  • Making templates translatable
• Creating a language file
• Specification of language files
• Language Metadata
• Loading extra language files
• Debugging a translation

ACL Topics

• Access Control List
• Adding ACL rules to your component

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Form Fields

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• <translate> Introduction to the Form classes in Joomla</translate>
• <translate> Joomla Core Form Fields</translate>
• <translate> Creating a custom form field type</translate>
• <translate> Overriding the "Rules" Form Field</translate>

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Form Rules & Validation

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• <translate> Form validation</translate>

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• How to add CSRF anti-spoofing to forms
• Securing Joomla! extensions
• Why do most of the Joomla! PHP files start with defined(' JEXEC')?
• Register Globals best practices (only relevant if your Joomla Site runs on PHP 5.3 or below)</translate>

Misc

• Retrieving request data using JInput and newer
• Retrieving data from GET and POST requests
• How to use the filesystem package
• Application execution order
• Accessing the current user object
• Adding JavaScript and CSS to the page
• Constants used in the Joomla Framework.
• Create a stand-alone application using the Joomla! Framework
• How to use user state variables
• Cache and Using caching to speed up your code
• Using the installer API to support package installation
• How to add tooltips to your Joomla! website
• Display error messages and notices.
• Sharing layouts across views or extensions with JLayout
• Using JLog
• JSON Responses with JResponseJson

Contributing to Documentation

<translate> The development of Joomla developer documentation is carried out primarily by the Documentation Working Group. There is currently one sub-projects of interest to developers:</translate> <translate>

• Developer Tutorials Project</translate>

<translate> When creating a new page, ensure you place the following marker at the bottom of the page so it is included in the category list:</translate>

[[Category:Development]]

<translate> If you locate other articles you think are relevant to developers, please add this marker to those pages.</translate>

Suggested topics

This is a short list of articles that might be written to support developers. Please feel free to add further topic ideas.

• Adding configuration objects to modules and plugins.
• Storing data in the session between page loads.
• Suppressing output of extra HTML.
• Using the filter package.

  Describe how and when to use the Filter package and explain what needs to be filtered for various situations (for queries, for URLs, etc)

• Using the registry package

  How to load and store XML files and how to work with them

• Creating component feeds (RSS/ATOM)
• Generating paths for client side and server side
• Acessing information from the request

  This focuses on using the JBrowser class to retrieve information about the features available in the user's browser.

• Creating an editor plugin
• What can be done with a user plugin
• Cloaking email addresses
• Using the caching system in your component. This might be enough (for now?) → Cache
• Extending Joomla's MVC Architecture
• How to release a distribution tarball.
• Creating a library for your extension(s).