From Joomla! Documentation
- 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
- 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