debian-jessie-main.xml.gz
. For Fedora 20 (Heisenbug) updates it would be fedora-20-updates.xml.gz
. 3rd-party repositories use a vendor name and repository-name combination, for example Ubuntu PPAs might get ppa-ubuntu12.04-username-foobar.xml
.
/usr/share/app-info/xmls
stores all AppStream data which has been installed via software packages, while /var/cache/app-info/xmls
stores application data which was downloaded by the package manager or placed there by other tools (e.g. Listaller). The XML files can either be plain files or be compressed with gzip. It is always a good idea to compress the files, because they tend to become quite large.
<applications>
tag as root element. It has all the <application>
elements as children. Data to fill the application elements is usually taken from their Desktop files and package data. However, if an application ships AppData files (see Section 2.2, “AppData XML files”), values defined there should override data from any other source. The <application>
element must at least have an id
, name
, summary
, pkgname
and icon
tag. All possible tags are:
<id type="desktop">
tag is the same name as the installed .desktop file for the application. Additional identifiers are possible later, but right now desktop
is the only supported type.
<project_license>
tag is indicating the license of your project/application. It should be a string in SPDX format. Licenses may be combined using and and or logic. Possible values include:
<description> <p> Power Statistics is a program used to view historical and current battery information and will show programs running on your computer using power. </p> <p>Example list:</p> <ul> <li>First item</li> <li>Second item</li> </ul> <p> You probably only need to install this application if you are having problems with your laptop battery, or are trying to work out what programs are using significant amounts of power. </p> </description>
homepage
should be a link to the upstream homepage for the application. It is planned to allow links to application's FAQ and forums later.
<project_group>
tag identifies a project with a specific upstream umbrella project. Known values include GNOME, KDE, XFCE, LXDE, Mozilla
and MATE
, although other umbrella projects like Yorba
would make sense too.
Note
<icon>
tag describes the application's icon. It can be of the type stock
, cached
, local
, or url
.
stock
icons are loaded from stock. The icon name should never include any file-extension or path.
cached
icons are loaded from the AppStream icon cache. The icon tag should contain the icon file name, including it's extension.
local
icons are reserved for AppStream data installed by local applications or via 3rd-party application installers, such as Listaller. They should specify a full file path.
remote
icons loaded from a remote URL. This is currently not implemented anywhere, but might be used in future.
<icon type="stock">gimp</icon> <icon type="cached">firefox.png</icon> <icon type="local">/usr/share/pixmaps/foobar.png</icon> <icon type="remote">http://example.com/icons/foobar.png</icon>
<icon/>
tags might be combined for one application, e.g. to define a stock
icon and a cached
icon. Software-Centers should always prefer the stock icon, if it is available, and fall back to the other icon types if they can not find it. The libappstream library makes it easy to do that, if you are not accessing the Xapian database manually.
cached
over local
over remote
icons when setting the non-stock icon for the application.
<mimetype>
tags, describing the mime types this application supports. The data can usually be fetched from the Desktop files. Example:
<mimetypes> <mimetype>text/html</mimetype> <mimetype>image/jpeg</mimetype> <mimetype>application/rss+xml</mimetype> </mimetypes>
<category>
tags, describing the categories this application is in. This data is usually taken from Desktop files, a list of categories can be found in the Freedesktop menu spec. Example:
<categories> <category>GNOME</category> <category>GTK</category> <category>Network</category> <category>Telephony</category> </categories>
Deprecated Tags
<appcategories>
with its <appcategory>
child elements is deprecated API. AppStream parsers should handle these tags just like the category
tags, there is no difference except for the name.
<keyword>
tags, describing keywords for the application, to make it easier to find in a software center. The data is taken from Desktop files. Example:
<keywords> <keyword>IDE</keyword> <keyword>development</keyword> <keyword>programming</keyword> </keywords>
<screenshot>
tags, describing screenshots which are available for the application. A screenshot tag my have the attribute type="default"
, marking it as the application's default screenshot, which primarily represents it in a software center.
<screenshot>
is defined by several images of different sizes. All images should have their width and hight set as arguments. Also, one of the images shoukd be marked as type="source"
, indicating that it is the unscaled version of the screenshot. Images of type="thumbnail"
define thumbnails of the screenshot.
<caption>
tag, describing the screenshot's caption. This is usually what the user can see on the image shown. The tag is translatable.
<screenshots> <screenshot type="default"> <caption>Foobar showing kitchen-sink functionality</caption> <caption xml:lang="si">Foobar shoeewing kischän-sünk funzionality</caption> <image type="source" width="800" height="600">http://www.example.org/en_US/main.png</image> <image type="thumbnail" width="200" height="150">http://www.example.org/en_US/main-small.png</image> </screenshot> <screenshot> .... </screenshot> </screenshots>
<compulsory_for_desktop>
tag indicates that the application which the data belongs to is essential for the functionality of the defined desktop environment. Examples for compulsory applications are the GNOME-Shell
by the GNOME-Project, or the Plasma-Desktop
by KDE, as well as things like iBus
or the desktop login manager.
<compulsory_for_desktop>
tag are allowed, so a project can be essential for many desktops. The distributor decides which applications should be made compulsory, however it is generally a good idea to follow upstream's recommendations on that matter.
<?xml version="1.0"?> <applications version="0.1"> <application> <id type="desktop">firefox.desktop</id> <pkgname>firefox-bin</pkgname> <name>Firefox</name> <name lang="en_GB">Firefoux</name> <summary>Web browser</summary> <summary lang="fr_FR">Navigateur web</summary> <project_license>MPL-2</project_license> <keywords> <keyword>internet</keyword> <keyword>web</keyword> <keyword>browser</keyword> <keyword lang="fr_FR">navigateur</keyword> </keywords> <icon type="stock">web-browser</icon> <icon type="cached">firefox.png</icon> <categories> <category>network</category> <category>web</category> </categories> <mimetypes> <mimetype>text/html</mimetype> <mimetype>text/xml</mimetype> <mimetype>application/xhtml+xml</mimetype> <mimetype>application/vnd.mozilla.xul+xml</mimetype> <mimetype>text/mml</mimetype> <mimetype>application/x-xpinstall</mimetype> <mimetype>x-scheme-handler/http</mimetype> <mimetype>x-scheme-handler/https</mimetype> </mimetypes> <url type="homepage">http://www.mozilla.com</url> <screenshots> <screenshot type="default"> <image type="source" width="800" height="600">http://www.awesomedistro.example.org/en_US/firefox.desktop/main.png</image> <image type="thumbnail" width="200" height="150">http://www.awesomedistro.example.org/en_US/firefox.desktop/main-small.png</image> </screenshot> </screenshots> </application> <!-- more applications here! --> </applications>