i18n in the Back-end

All new work should use gettext for translation. Translation using .tab files should only exist in the legacy code and will be replaced by gettext.

Gettext system documentation

In core

echo _('Homepage');

In plugins

We use the domain feature provided by gettext in order to have i18n in plugins.

echo dgettext('tuleap-proftpd', 'File');


The command xgettext extracts strings without being able to interpret PHP constants or variables. Don’t try to be too smart and don’t put the domain tuleap-proftpd in a variable or a constant, we need to repeat ourselves.


You can use localized strings from core or other plugins (beware of dependencies!) in a given plugin.

In REST routes

When error messages have functional meaning that cannot be deducted by the client (for example an error message explaining why a tracker expert query is invalid), then they should be translated with the following pattern:

throw new I18NRestException(
         dgettext('tuleap-taskboard', "Could not find artifact to add with id %d."),


echo sprintf(
        "The field '%s' doesn't exist",
        "The fields '%s' don't exist",
    implode("', '", $nonexistent_fields)
// The field 'summary' doesn't exist
// or
// The fields 'summary', 'details' don't exist


Do not concatenate strings to build a sentence! For example nb + " pull requests" or "It is " + "suspended" are not allowed.


  1. Add a new localizable string.

  2. Run make generate-po. This will update corresponding .pot files that are templates for your localization files.

  3. Edit localization files in site-content/fr_FR/LC_MESSAGES/tuleap-xxxx.po with your favorite editor (poedit is fine).

  4. Once you have localized your sentences, run make generate-mo (some editors, like poedit, generate .mo files for you). You may need to restart your webserver (docker exec tuleap-web systemctl restart tuleap-php-fpm).

  5. Refresh your browser, and voilà!


If you are introducing gettext in a plugin, you must mkdir plugins/<name>/site-content/fr_FR before calling make generate-po.

Furthermore you must declare your domain in the constructor of your plugin. For example, for tracker plugin, in trackerPlugin.class.php:

bindtextdomain('tuleap-tracker', __DIR__.'/../site-content');


On our dev setup (tuleap-aio-dev) you must ensure that “fr_FR” locale is installed (locale -a). If it is not the case, run localedef -i fr_FR -f UTF-8 fr_FR.UTF-8.

tab files

This system is based on a key/value pair. PHP code references a key (actually a primary and a secondary keys) which is replaced by the full sentence, according to the user preferences.

Language files are available in the site-content/ directory, for example site-content/en_US/include/include.tab. The same file exists for the french version: site-content/fr_FR/include/include.tab.

These language files follow a defined syntax:

key1 [tab] key2 [tab] translated string

and sentences are separated by a carriage return. Keys are split in different files for convenience, but are “compiled” in a big unique file at execution.


include_exit        error   An error occured

The class that manages i18n is BaseLanguage (src/common/language/BaseLanguage.class.php). It is initialized by pre.php, and language is set according to the user preferences. This php code will return the matching string defined in language files:

$GLOBALS['Language']->getText('include_exit', 'error'));


For performance reasons, Tuleap localization is kept in a cache file. When you are done adding / editing .tab files, connect to your web container and run the following command to clear this cache and see your modifications:

$ tuleap --clear-caches