There is a lot in the core package of Joomla!. Words like components, modules, plug-ins, templates and languages you have already heard before. Besides these well known parts, Joomla! also consists of lesser known parts like libraries and packages. Additional components, modules, plugins and languages are listet in the Joomla! extension directory. The Joomla! project has no central place for templates und libraries. The reason for this is simple. Libraries are developed outside of the Joomla project and many were also used by other open source projects. Templates are something very individual and are, therefore, available on the websites of their designers. A central directory especially for templates would be helpful in the future.
With the rewritten extension manager you can install, update, discover und manage extensions directly from your Joomla! administration.
Let's have a look at all your installed 110 extensions in Extensions → Extension Manager → Manager. You can filter this list by various parameters. Some extensions are protected. Your Joomla! installation would no longer work if you uninstalled these protected extensions (Figure 1).
Figure 1: Table with all installed extensions
In this area you can enable, disable and uninstall extensions. Enabling and disabling works just like a light switch. You simply switch the extension on and off, all the related data are still kept. If you unistall an extension, it will be deleted. Often extensions, usually components, create additional database tables while installing. It's up to the component de-installation routines, whether these tables will be deleted or not during de-installation. Check the manual or readme file in advance to avoid suprises.
The last icon in the toolbar is the cache icon. Every extension is able to cache data. You can clear this cache separately for every extension. If your Joomla! site attracts lots of visitors and you don't want to clear the whole cache for performance reasons, you may need this function.
If you filter the list for libraries, you will find these four articles with the corresponding version number:
- Joomla! Application Framework, which is the 'Platform' where the Joomla! 1.7 CMS is based on.
All the other extensions are built upon this framework.
- PHPMailer is a class, written in PHP for sending emails. This is used in the mail to component.
- SimplePie is a class, written in PHP for managing RSS and Atom feeds. This is used in the newsfeeds component.
- phputf8 is a UTF-8-capable library of functions mirroring PHP's own string functions. You can get an idea what this library does by reading UTF-8 and PHP.
If you filter the list for packages, you will find nothing in Joomla! core. If you installed a language other than English, you will find that language package there.
In this area, third-party extensions and the version of Joomla! core itself are listed. Here you can check for available extension updates available by clicking the Find Updates icon. If Joomla! finds an extension update and you want to update automatically, you have to fill in the FTP setttings form in Global Configuration → Server → FTP settings. Then select the extension you wish to update and click the Update icon. The process is fully automatic and you are going to receive messages and hints, depending on the extension, while updating.
You can install extensions in three different ways (Figure 2):
Figure 2: Installing extensions
- Upload a Package file
If you have downloaded a zip file to your local PC that contains a Joomla! extension, you can use this option to upload and install your extension.
- Install from Directory
If you have uploaded a zip file at your document root directory on your web server that contains a Joomla! extension, you can use this option to extract and install your extension.
- Install from URL
If you know the URL of a zip file that contains a Joomla! extension, you can use this option to download, extract and install your extension.
Sometimes things are go wrong during the installation process, like files being too big, permissions not being set correctly or for other strange reasons. In this area, Joomla! tries to find extensions, which are not installed but nevertheless exist in the file directory. If one or more extensions are discovered, you can install them by using the FTP feature. Don't forget the correct FTP credentials in Global Configuration → Server → FTP settings.
By using the discover operation, you can install multiple extensions at the same time!
Error messages related to installations and updates will appear in this area. If you can't solve the problem by yourself, google the message text, you'll usually find a solution or at least some advice.