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Translation has been divided into two domains. First, there is the translation of server messages sent to connecting clients. This issue has been punted for now. Second there is the translation of the client and its libraries.
The gettext package provides services for translating messages. It uses the xgettext tool to extract strings from the sources for translation. This works by extracting the arguments of the _(), N_() and Q_() macros. _() is used in context where function calls are allowed (typically anything except static initializers). N_() is used whenever _() isn't. Strings marked with N_() need to be passed to gettext translation routines whenever referenced in the code. For an example, look at how the header and footer are handled in subversion/svn/help-cmd.c. Q_() is used for messages which have singular and plural version.
Beside _(), N_() and Q_() macros also U_() is used to mark strings which will not be translated because it's in general not useful to translate internal error messages. This should affect only obscure error messages most users should never ever see (caused by bugs in Subversion or very special repository corruptions). The reason for using U_() is to explicitly note that a gettext call was not just forgotten.
When using direct calls to gettext routines (*gettext or *dgettext), keep in mind that most of Subversion code is library code. Therefore the default domain is not necessarily Subversion's own domain. In library code you should use the dgettext versions of the gettext functions. The domain name is defined in the PACKAGE_NAME define.
All required setup for localization is controlled by the ENABLE_NLS conditional in svn_private_config.h (for *nix) and svn_private_config.hw (for Windows). Be sure to put
as the last include in any file which requires localization.
Also note that return values of _(), Q_() and *gettext() calls are UTF-8 encoded; this means that they should be translated to the current locale being written as any form of program output.
The GNU gettext manual (http://www.gnu.org/software/gettext/manual/html_node/gettext_toc.html) provides additional information on writing translatable programs in its section "Preparing Program Sources". Its hints mainly apply to string composition.
Currently available translations can be found in the po section of the repository. Please contact firstname.lastname@example.org when you want to start a translation not available yet. Translation discussion takes place both on that list and on dedicated native language mailing lists (email@example.com).
The Makefile build targets locale-gnu-* (used to maintain po files) require GNU gettext 0.13 or newer. Note that this is not a requirement for those wanting to compile the *.po files into *.mo's.
Before starting a new translation please contact the subversion development mailing list to make sure you are not duplicating efforts. Also please note that the project has a strong preference for translations which are maintained by more than one person: mailing the lists with your intentions might help you find supporters.
After that, you should perform the following steps:
msginit --locale LOCALE -o LOCALE.poin the
subversion/podirectory of your working copy. LOCALE is the ll[_LL] language and country code used to identify your locale.
Steps (2) and (3) generate a Makefile; step (4) generates
The Subversion project has a policy not to put names in its files, so please apply the two changes described below.
The header in the newly generated .po file looks like this:
# SOME DESCRIPTIVE TITLE. # Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER # This file is distributed under the same license as the PACKAGE package. # FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
Please replace that block with the following text:
# <Your language> translation for subversion package # Licensed to the Apache Software Foundation (ASF) under one # or more contributor license agreements. See the NOTICE file # distributed with this work for additional information # regarding copyright ownership. The ASF licenses this file # to you under the Apache License, Version 2.0 (the # "License"); you may not use this file except in compliance # with the License. You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, # software distributed under the License is distributed on an # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY # KIND, either express or implied. See the License for the # specific language governing permissions and limitations # under the License.
The first translation block in the .po file contains two lines like these:
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" "Language-Team: LANGUAGE <LL@li.org>\n"
Please replace those with these two lines:
"Last-Translator: Subversion Developers <firstname.lastname@example.org>\n" "Language-Team: YOUR LANGUAGE <email@example.com>\n"
To be documented
Before submitting to the mailing list or committing to the repository, please make sure your po file 'compiles'. You can do this with these steps (on Makefile based systems):
./configure(with the appropriate arguments)
The autogen.sh step is important, since it adds new po files as dependencies of the 'locale' build target. Note however that steps 1 and 2 are only needed once after you have added a new translation.
Please don't mail large po files to the mailing lists. There are many subscribers on firstname.lastname@example.org who are on slow links and do not want to receive a large file by email. Instead, place the po file somewhere on the Internet for download, and just post the URL. If you do not have a site available, please ask on dev@ and someone will help you find a location.
Of course, if you have commit access to the Subversion repository, you can just commit the po file there, assuming all other requirements have been satisfied.
The Makefile based part of the build system contains a make target to facilitate maintenance of existing po files. To update po files on systems with GNU gettext run
To only update a particular language, you may use
make locale-gnu-po-update PO=ll
where ll is the name of the po file without the extension (i.e. PO=sv).
It is recommended that the .po update is done by using two commits; one after the "make locale-gnu-po-update", and one after the translation is done. This has two advantages:
gettext(1)produces lots of line number changes which makes the resulting diff hard to review by the other translators. By committing twice, all the line number changes are stored in the first commit, and the second commit contains all the actual translations with no extra garbage.
Editing po files in trunk is pretty straightforward, but gets a bit more
complicated when those changes are going to be transferred to a release
branch. Project policy is to make no direct changes on release branches,
everything that is committed to the branch should be merged from trunk.
This also applies to po files. Using
svn merge to do the job
can lead to conflicts and fuzzy messages due to the changes in line numbers
and string formatting done by gettext.
svn mergeto do branch updates. The following rules apply:
The above list is a complete enumeration of all operations allowed on po files on branches.
Merging messages from trunk revision X of YY.po to your branch working copy can be done with this command:
svn cat -r X ^/subversion/trunk/subversion/po/YY.po | \ po-merge.py YY.po
On some gettext implementations we have to ensure that the mo
files — whether obtained through the project or created
locally — are encoded using UTF-8. This requirement stems
from the fact that Subversion uses UTF-8 internally, some
implementations translate to the active locale
and the fact that
bind_textdomain_codeset() is not portable
Some gettext implementations use a section with a msgid "" (empty string) to keep administrative data. One of the headers suggested is the 'Last-Translator:' field. Because the Subversion project has a policy not to name contributors in specific files, but give credit in the repository log messages, you are required not to put your name in this field.
Since some tools require this field to consider the po file valid (i.e. Emacs PO Mode), you can put "email@example.com" into this field.
The GNU translation project (http://www2.iro.umontreal.ca/~gnutra/po/HTML/) attempts to organise translation attempts and get translators for various packages. Some teams have guidelines to stimulate consistency across packages.
The project has standardised the use of quotes. Some translation teams have done the same. If there is no translation team for your locale or they did not standardise quoting, please follow the project guidelines elsewhere in this guide. If they did: follow them :-)
Since translators will generally see all error messages in the code, it's important to know that there is a special section in this document about this category of strings. Here the same applies as does for the quotes: Adhere to them on all points for which there is no explicit policy set out by the translation team for your language.