Manifest files

From Joomla! Documentation

Revision as of 09:16, 23 January 2014 by Tom Hutchison (Talk | contribs)

Within Joomla there are manifest files for all of the extensions. These files include the general installation information as well as parameters for the configuration of the extension itself. Since Joomla! 2.5 Joomla 2.5, there are very few differences between the manifest file formats for the different types of extensions, allowing each type to access the full power of the Joomla! installer.

Naming conventions

The file must be named manifest.xml or <extension_name>.xml and located in the root directory of the installation package.


Root element

The primary tag of the installation file is:


This starting and closing tags are now valid for all extensions. The new tag <extension> replaces the old <install></install> from Joomla Joomla 1.5. The following attributes are allowed within the tag:

Attribute Values Applicable to Description
type component
All extensions This attribute describes the type of the extension for the installer. Based on this type further requirements to sub-tags apply.
version 2.5
All extensions String that identifies the version of Joomla for which this extension is developed.
method install
All extensions The default value install will be also used if the method attribute is not used. The install value means the installer will gracefully stop if it finds any existing file/folder of the new extension.
client site
Modules The client attribute allows you to specify for which application client the new module is available.
group string Plugins The group name specifies for which group of plugins the new plugin is available. The existing groups are the folder names within the directory /plugins. The installer will create new folder names for group names that do not exist yet.


The following elements can be used to insert metadata. None of these elements are required; if they are present, they must be a child of the root element.

<name> – raw component name (e.g. com_banners). 
<author> – author's name (e.g. Joomla! Project)
<creationDate> – date of creation or release (e.g. April 2006)
<copyright> – a copyright statement (e.g. (C) 2005 - 2011 Open Source Matters. All rights reserved.)
<license> – a license statement (e.g. NU General Public License version 2 or later; see LICENSE.txt)
<authorEmail> – author's email address (e.g.
<authorUrl> – URL to the author's website (e.g.
<version> – the version number of the extension (e.g. 1.6.0)
<description> – the description of the component. This is a translatable field. (e.g. COM_BANNERS_XML_DESCRIPTION)

Note: The <name> and <description> tags are also translatable fields so that the name and description of the extension can be shown to the user in their native language.

Front-end files

	<files folder="from-folder">

Files to copy to the front-end directory should be placed in the <files> element. You can use the optional folder attribute to specify a directory in the ZIP package to copy from. Each file to copy must be represented by a <filename> element. If you want to copy an entire folder at once, you can define it as a <folder>.

Media files

	<media folder="media" destination="com_example">

This example will copy the file(s) (/media/com_example_logo.png) and folders ( /media/css/ and /media/js/ ) listed to /media/com_example/, creating the com_example folder if required. You can use the optional folder attribute to specify a directory in the ZIP package to copy from (in this case, media).

Extensions should be storing assets they need to be web accessible (JS, CSS, images etc) in media. Amongst other things this feature was added as step in the progression to multi-site support and the eventual move of code files (PHP) out of the web accessible areas of the server.


Administration section

		<!-- various elements -->

The administration section is defined in the <administration> element. Since only components apply to both the site and the administrator, only component manifests can include this element.

Back-end files

Files to copy to the back-end directory should be placed in the <files> element under the <administration>. You can use the optional folder attribute to specify a directory in the ZIP package to copy from. See Front-end files for further rules.

Menu links and submenus

		<menu link="anoption=avalue">COM_EXAMPLE_SUBMENU_ANOPTION</menu>
		<menu view="viewname">COM_EXAMPLE_SUBMENU_VIEWNAME</menu>

The text for the main menu item for the component is defined in the <menu> item, a child of <administration>. A <submenu> element may also be present (also a child of <administration>), which may contain more menu items defined by <menu>.

Additionally, each <menu> item can define the following attributes:

Attribute Description
link A link to send the user to when the menu item is clicked
img The (relative) path to an image (16x16 pixels) to appear beside the menu item.

Must be an url compatible as a file too (e.g. no spaces) !

string An URL parameter to add to the link. For example, <menu view="cpanel">COM_EXAMPLE</menu> in com_example's XML manifest would cause the URL of the menu item to be index.php?option=com_example&view=cpanel.

The value inside the tag is the menu's label. Unlike Joomla! 1.5, you can not use a natural language string. For example, if you would enter "Example Component" instead of COM_EXAMPLE, it would result in your component name appearing as example-component in the menu and you would be unable to provide a translation. In order to provide a translation you need to create a file named en-GB.com_example.sys.ini in administrator/languages/en-GB (you can use the manifest's tag as shown below. This method can still be used in 2.5  3.x.

<!-- Joomla! 1.5 language tag -->
<languages folder="langfiles">
	<language tag="en-GB">en-GB.com_example.ini</language>

Since Joomla! 1.6 it has been encouraged placing your extension's language files in your extension folder. Joomla! will then automatically load your language files.

By storing extension language files in the extension folder, you gain benefits when removing a language from the Joomla! installation: As your language files will not be removed, when reinstall the language again you can use those files without installing them again.

The structure of the language folder for frontend and backend is the same. You put them in the language tag (e.g. en-GB ) of each language in your language folder i.e. language/en-GB/. You have to specify those folders in the front-end and back-end files too.

In your manifest you simply include the 'language' folder in your files section, the sub-directories for each language automatically be copied. Inside the <files> group you simply add a <folder> element alongside the items in the <files> group as shown in this example:

	<filename plugin="alpha">alpha.php</filename>

It is also notable that both ways can work together. Here is an example from core:

	<filename plugin="languagecode">languagecode.php</filename>
	<language tag="en-GB">language/en-GB/en-GB.plg_system_languagecode.ini</language>
	<language tag="en-GB">language/en-GB/en-GB.plg_system_languagecode.sys.ini</language>

The advantages of this solution are the following:

All ini files present in the core folder have precedence over the files in the extension language/ folder. For example a sys.ini file will always be loaded from core folders in back-end if it exists, except when installing an extension which contains a sys.ini file in a language folder. In that case and only that case, the sys.ini file in the extension folder will display its translated content at install time. This is very handy as a developer can have 2 sys.ini files with different contents. A description of the successful install as well as a tutorial in back-end for example.

Also, it is much easier for a user needing an ini file for an extension that does not provide it in the language desired, to add it in the main folders. No risk for it to be deleted in case of uninstalling the extension by mistake or any other reason.

See also:

During development you can turn on language debugging in the Joomla! global configuration. So you can investigate if a problems arises. As of 3.2, this is necessary to help debug as en-GB is always loaded first when not in debug mode to prevent displaying Constants.

Script file


An optional script file (PHP code that is run before, during and/or after installation, uninstallation and upgrading) can be defined using a <scriptfile> element. This file should contain a class named "<element_name>IntallerScript" where <element_name> is the name of your extension (e.g. com_componentname, mod_modulename, etc.). Plugins requires to state the group (e.g. plgsystempluginname). Library packages do not support scriptfiles. The structure of the class is as follows:

class com_componentnameInstallerScript
	 * Constructor
	 * @param   JAdapterInstance  $adapter  The object responsible for running this script
	public function __construct(JAdapterInstance $adapter);
	 * Called before any type of action
	 * @param   string  $route  Which action is happening (install|uninstall|discover_install|update)
	 * @param   JAdapterInstance  $adapter  The object responsible for running this script
	 * @return  boolean  True on success
	public function preflight($route, JAdapterInstance $adapter);
	 * Called after any type of action
	 * @param   string  $route  Which action is happening (install|uninstall|discover_install|update)
	 * @param   JAdapterInstance  $adapter  The object responsible for running this script
	 * @return  boolean  True on success
	public function postflight($route, JAdapterInstance $adapter);
	 * Called on installation
	 * @param   JAdapterInstance  $adapter  The object responsible for running this script
	 * @return  boolean  True on success
	public function install(JAdapterInstance $adapter);
	 * Called on update
	 * @param   JAdapterInstance  $adapter  The object responsible for running this script
	 * @return  boolean  True on success
	public function update(JAdapterInstance $adapter);
	 * Called on uninstallation
	 * @param   JAdapterInstance  $adapter  The object responsible for running this script
	public function uninstall(JAdapterInstance $adapter);

Update servers

        <server type="extension" priority="1" name="Extension Update Site"></server>
        <server type="collection" priority="2" name="Collection Update Site"></server>

Update servers can be defined in the <updateservers> element, a child of the root. This element may contain one or more <server> element, each describing a location to fetch updates from. Each <server> item can define the following attributes:

Attribute Values Description
type extension
The update server type
priority integer The priority of the update server
name string The name of the update server

More info:


For a real-life example, see the manifest of the Banner component in the latest version of Joomla! 2.5.

The Joomla testing process uses several extensions to test whether the installer works correctly. The latest versions of the manifests of these extensions are: