| PO-DEBCONF(7) | po-debconf | PO-DEBCONF(7) |
po-debconf - introduction
The goal of "debconf" was to make package configuration user-friendly. In order to achieve this, it is important to ensure that users will get the question in their own language. Translators need a framework to easily work on translations without having to track package development; "po-debconf" was designed to be able to work with standard "gettext" tools when translating debconf templates files.
If you are adding debconf support to your package, you have written a templates file containing English text. To add proper i18n support into your package, you need to:
[type: gettext/rfc822deb] templates
Paths are relative to the parent directory.
In order to help translators, PO files in your package should always be up-to-date, otherwise they may waste their time translating unused strings. For that, simply call the following command without arguments:
$ debconf-updatepo
You should run this command every time you change templates in English, but also when you receive new or updated translations, because translators may have worked on an obsolete PO file.
If you rename, add or remove some templates files, remember also to edit debian/po/POTFILES.in accordingly, otherwise English strings are missing from PO files and will be displayed to users even if PO files are fully translated.
The debconf-updatepo program is idempotent, it modifies PO files only if their content has been updated. Thus the best way to provide up-to-date PO files in your source package is to call this command from the "clean" target of the debian/rules file.
Please note that you need to run debconf-updatepo even if you use dh_installdebconf. The latter calls po2debconf which used to call debconf-updatepo if outdated files were detected, but this is no more the case because it was not a good solution for at least two reasons:
You have to make sure that when your package is compiled, translations will get into the built package. You can do that manually, or automatically using the dh_installdebconf script (make sure to have a versioned build dependency against "debhelper (>= 4.1.16)").
To do that manually, you'll have to merge the templates and the translations at compile time (and to have a build depend against "po-debconf") like this:
$ po2debconf debian/templates > debian/tmp/DEBIAN/templates
BE CAREFUL: the two files called templates are not the same at all. The first one contains only the English text, with marks to denote some fields to be translated while the second contains all languages. That is to say that you CANNOT keep only the merged templates, or you won't be able to deal with translations as people submit them to you.
The new templates file source format is almost identical to one of distributed templates files, but translatable fields are prepended with an underscore. Example:
Template: debconf/frontend Type: select _Choices: Dialog, Readline, Gnome, Editor, Noninteractive Default: Dialog _Description: Interface to use for configuring packages: Packages that use debconf for configuration share a common look and feel. You can select the type of user interface they use. . The dialog frontend is a full-screen, character based interface, while the readline frontend uses a more traditional plain text interface, and the gnome frontend is a modern X interface. The editor frontend lets you configure things using your favorite text editor. The noninteractive frontend never asks you any questions.
Since "po-debconf" 0.6.0, localized fields may contain two leading underscores. In this case, the field value is supposed to be a comma separated list of values, which are put in separate msgids. Thus if the previous example did contain
__Choices: Dialog, Readline, Gnome, Editor, Noninteractive
there would be 5 different msgids. Note that spaces after commas are not significant.
When a choices list never changes, "_Choices" may be considered fine. However, splitting such lists may help avoiding frequent mistakes in translations such as omitting a choice or using non-standard commas. For such reasons, the use of "__Choices" will ease translator's life and is strongly recommended.
Unfortunately if you decide to switch from "_Choices" to "__Choices", all translations become fuzzy. Here is an explanation to make this change without translation loss (it requires "po-debconf" >= 1.0). Suppose that we want to switch the previous example to "__Choices". You copy the templates file into a temporary file.
$ cp debian/templates debian/foo
Edit debian/foo and keep only "Template", "Type" and "_Choices" fields, which are in this example
Template: debconf/frontend Type: select _Choices: Dialog, Readline, Gnome, Kde, Editor, Noninteractive
Run debconf-gettextize with "--merge" and "--choices" flags to build PO files as if "__Choices" was written, and merge these PO files to existing ones:
$ debconf-gettextize --merge --choices debian/foo
Eventually you have to remove foo and manually edit debian/templates to replace "_Choices" by "__Choices" before debconf-updatepo is run.
"Dpkg" maintainers decided that by convention lines beginning with a number sign ("#") are comments in debian/control files, and "po-debconf" follows this rule. Since "po-debconf" 0.8.0, such comments are written into PO files, and can then contain valuable information for translators. Incidentally all previous "po-debconf" versions ignore lines which do not contain a colon, thus if your comments does not contain any colons, there is no need to add a versioned build dependency against "po-debconf". Here is an example:
Template: debconf/button-yes Type: text # Translators, this text will appear on a button, so KEEP IT SHORT _Description: Yes
Special comments have been introduced in "po-debconf" 1.0 to deal with strings which are composed of several items (as with Choices field) or paragraphs (like Description). With these directives, developers have a better control over what is exposed to translators. They are in the form "#flag:directive"; directives are detailed below.
Template: partman-basicfilesystems/fat_mountpoint
Type: select
#flag:translate:3,4
__Choices: /dos, /windows, Enter manually, Do not mount it
_Description: Mount point for this partition:
"Enter manually" and "Do not mount it" will appear in PO files but not "/dos" and "/windows". When an exclamation mark follows the translate keyword, spec specifies which strings will be discarded from PO files, all other strings are printed. Previous example is similar to
Template: partman-basicfilesystems/fat_mountpoint
Type: select
#flag:translate!:1,2
__Choices: /dos, /windows, Enter manually, Do not mount it
_Description: Mount point for this partition:
The same keyword can also be applied to the Description field to make sure that some strings are not translated.
Template: partman-crypto/options_missing
Type: error
#flag:translate!:3
_Description: Required encryption options missing
The encryption options for ${DEVICE} are incomplete. Please
return to the partition menu and select all required options.
.
${ITEMS}
But this is hazardous because context may be dropped from PO files, please add comments in this case so that translators are not confused.
Template: arcboot-installer/prom-variables
Type: note
# Translators, the 4th string of this description has been dropped
# from PO files. It contains shell commands and should not be
# translated.
#flag:comment:3
# "Stop for Maintenance" should be left in English
#flag:translate!:4
_Description: Setting PROM variables for Arcboot
If this is the first Linux installation on this machine, or if the
hard drives have been repartitioned, some variables need to be set
in the PROM before the system is able to boot normally.
.
At the end of this installation stage, the system will reboot.
After this, enter the command monitor from the "Stop for
Maintenance" option, and enter the following commands:
.
setenv OSLoader arcboot
setenv OSLoadFilename Linux
.
You will only need to do this once. Afterwards, enter the "boot"
command or reboot the system to proceed to the next stage of the
installation.
The example above has a comment without "#flag:comment" directive, where an implicit "#flag:comment:*" is added. This comment appears with all strings, but the one about Stop for Maintenance is printed only before the relevant string.
Usually translators notice on the status web pages (see below) that translations are outdated, and send patches which will be included in future uploads. But developers are encouraged to ask maintainers of outdated translations for an update before an upload, for instance one week in advance. A dedicated tool, podebconf-report-po, has been written for this purpose. Do not hesitate to abuse it!
You will find that debconf-loadtemplate will not accept a templates file with i18n markups. However, it will accept a merged file, so if you have been debugging your debconf setup like this
rm /tmp/{config,templates}.dat{,-old}
debconf-loadtemplate debian/templates
DEBIAN_PRIORITY=low debconf -freadline debian/config configure 28.0
you will now need something like this instead:
po2debconf debian/templates > debian/tmp/DEBIAN/templates
rm /tmp/{config,templates}.dat{,-old}
debconf-loadtemplate debian/tmp/DEBIAN/templates
DEBIAN_PRIORITY=low debconf -freadline debian/config configure 28.0
Such markers must be added to the end of the strings to translate, they must start with "[ " (a left bracket followed by a space) and end with "]" (right bracket), and may contain any character but brackets or new lines. For example "[ blahblah]" is a valid marker while "[ bla[bla]bla]" isn't. For Perl regexp addicts, the markers are recognized (and removed) using this rule:
$msg =~ s/\[\s[^\[\]]*\]$//s;
On the other hand "po-debconf" relies on "gettext" to detect fuzzy entries, and it does not treat spaces as special characters. Thus superfluous spaces must be removed at end of lines in master templates files, or they will appear in PO and POT files.
For the same reason, debconf-gettextize can mark text fuzzy because of mismatch with space characters, and translators have to manually unfuzzy such strings. This only happens once when converting templates to "po-debconf" format, unless you randomly change spaces in master templates files, which will be painful for translators.
The localized value must not be translated, but chosen from the English values listed in the Choices field. The best way to achieve this goal is to insert a comment in your templates file which will be copied into PO files.
Template: geneweb/lang
Type: select
__Choices: Danish (da), Dutch (nl), English (en), Esperanto (eo)
# You must NOT translate this string, but you can change its value.
# The comment between brackets is used to distinguish this msgid
# from the one in the Choices list; you do not have to worry about
# them, and have to simply choose a msgstr among the English values
# listed in the Choices field above, e.g. msgstr "Dutch (nl)"
_Default: English (en)[ default language]
_Description: Geneweb default language
The default value also appears in the Choices field, and both have different translations: the former is an untranslated value chosen among Choices values, whereas the latter is a normal translation. As "gettext" cannot have two different translations for the same msgid, both msgids must be different by using bracketed comments as described in a previous subsection.
Prior to "po-debconf" 0.8.0, such comments were not available and maintainers had to replace the _Default: field by _DefaultChoice: in order to highlight such fields in PO files:
#. DefaultChoice
msgid ""
"English[ default: do not translate bracketed material, put your "
"own language here but UNTRANSLATED. If it is not in the list, "
"put English (without bracketed material)]"
msgstr ""
"Swedish"
Plain comments in templates files are less error prone and are encouraged.
Statistics for "po-debconf" translations are available at <http://www.debian.org/intl/l10n/po-debconf/> (or from mirrors); they are automatically updated when new packages are uploaded. Only packages shipping debian/po/templates.pot and debian/po/POTFILES.in files are considered, so you should make sure your source package provides them.
Translators can grab PO and POT files from there, but they must always get in touch with the previous translator (her mail address can be found in the PO file) and/or their fellow translators on debian-l10n-<language>@lists.debian.org (if such a list does exist) to make sure that no one is currently working on the same translation, and read current bugreports against the package they are going to translate to see if a translation has already been reported.
After translating these files, they should submit their work to the maintainer as bug report of severity wishlist with the patch tag.
debconf-gettextize(1), debconf-updatepo(1), dh_installdebconf(1), podebconf-report-po(1), po2debconf(1), debconf-devel(7).
Martin Quinson <Martin.Quinson@ens-lyon.fr> Denis Barbier <barbier@linuxfr.org>
| 2018-11-20 |