luci/docs/i18n.md

Internationalization (i18n)

See online wiki for latest version.

Use translation function

Translations in JavaScript

Wrap translatable strings with _() e.g. _('string to translate') and the i18n-scan.pl and friends will correctly identify these strings for translation.

If you have multi line strings you can split them with concatenation:

var mystr = _('this string will translate ' +
	'correctly even though it is ' +
	'a multi line string!');

You may also use line continuations \ syntax:

var mystr = _('this string will translate \
	correctly even though it is \
	a multi line string');

Usually if you have multiple sentences you may need to use a line break. Use the <br /> HTML tag like so:

var mystr = _('Port number.') + '<br />' +
	_('E.g. 80 for HTTP');

Use <br /> and not <br> or <br/>.

If you have a link inside a translation, move its attributes out of a translation key:

var mystr = _('For further information <a %s>check the wiki</a>')
	.format('href="https://openwrt.org/docs/" target="_blank" rel="noreferrer"')

This will generate a full link with HTML For further information <a href="https://openwrt.org/docs/" target="_blank" rel="noreferrer">check the wiki</a>. The noreferrer is important so that it is opened in a new tab (target="_blank").

Translations in LuCI lua+html templates

Use the <%: text to translate %> as documented on Templates

Translations in Lua controller code and Lua CBIs

As hinted at in the Templates doc, the %: invokes a translate() function. In most controller contexts, this is already available for you, but if necessary, is available for include in luci.i18n.translate

Translation files

Translations are saved in the folder po/ within each individual LuCI component directory, e.g. applications/luci-app-acl/po/. The template is in po/templates/<package>.pot. The individual language translation files can be found at po/[lang]/[package].po.

In order to use the commands below you need to have the gettext utilities (msgcat, msgfmt, msgmerge) installed on your system. On Debian/Ubuntu, install them with sudo apt install gettext.

Initialize po files

When you add or update an app, run from your applications/luci-app-acl/ app folder:

../../build/i18n-add-language.sh

This creates the skeleton .po files for all available languages open for translation for your app.

Or from the luci repo root:

./build/i18n-add-language.sh

This creates the skeleton .po files for all existing languages open for translation for all sub-folders.

Rebuild po files (for existing languages)

After you make changes to a package, run:

./build/i18n-sync.sh applications/[application]

Example:

./build/i18n-sync.sh applications/luci-app-acl

This only updates those language .po files that already exist in applications/luci-app-acl/po/. See the previous step to add a new language.

Note: the directory argument can be omitted to update all po template and po files.

Some packages share translation files, in this case you need to scan through all their folders:

./build/i18n-scan.pl applications/[package-1] applications/[package-2] applications/[package-n] > [location of shared template]/[application].pot

This is what the mkbasepot.sh script does for the luci-base module:

./build/i18n-scan.pl \
    modules/luci-base modules/luci-compat modules/luci-lua-runtime \
    modules/luci-mod-network modules/luci-mod-status modules/luci-mod-system \
    protocols themes \
> modules/luci-base/po/templates/base.pot

Note: The translation catalog for the base system covers multiple components. Use the following commands to update it:

./build/mkbasepot.sh
./build/i18n-update.pl

LMO files

The *.po files are big so Luci needs them in a compact compiled LMO format. Luci reads *.lmo translations from the /usr/lib/lua/luci/i18n/ folder. E.g. luci-app-acl has an Arabic translation in luci-i18n-acl-ar package that installs /usr/lib/lua/luci/i18n/acl.ar.lmo file.

In order to quickly convert a single .po file to .lmo file for testing on the target system use the po2lmo utility. You will need to compile it from the luci-base module:

 $ cd modules/luci-base/src/
 $ make po2lmo
 $ ./po2lmo
 Usage: ./po2lmo input.po output.lmo

Now you can compile and upload the translation:

 ./po2lmo ../../../applications/luci-app-acl/po/ar/acl.po ./acl.ar.lmo
 scp ./acl.ar.lmo root@192.168.1.1:/usr/lib/lua/luci/i18n/

You can change languages in System /Language and Style and check the translation.