Version 4 (modified by 14 years ago) ( diff ) | ,
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Adding l10n support to Trac plugins (Trac ≥ 0.12)
Motivation
[FIXME: content needed, especially address the intended audience (plugin maintainers and developers in general) here - who should read on (and who shouldn't care at all)]
i18n vs. l10n (again)
[FIXME: is this needed?, well consider this is nice to the reader allowing to focus on i18n after coming from the greater scope of l10n, but be as short as possible when]
Background and basics of i18n support
The evolution of native support for Trac plugins is documented in ticket 7497. The final implementation as documented there in comment 12 was introduced to Trac trunk in changeset r7705 and finally done with changeset r7714. Adding the needed i18n helper functions is as easy as adding
from trac.util.translation import domain_functions _, tag_, N_, add_domain = domain_functions('tracmercurial', '_', 'tag_', 'N_', 'add_domain')
at the beginning of the main python script file of an existing or new plugin. To bring in the compiled message catalog for actually using the translated texts one will have to extend the __init__
function of plugins main class too. For a fictional plugin Foo this would be done like this:
def __init__(self): self._version = None self.ui = None # bind the 'foo' catalog to the specified locale directory locale_dir = pkg_resources.resource_filename(__name__, 'locale') add_domain(self.env.path, locale_dir)
assuming that folder locale
will reside in ./foo/locale/
within the directory structure (of the Python egg). If you didn't have it, add a import pkg_resources
to the beginning of the plugin script as well or the line locale_dir = ...
will throw an 'ImportError'.
[FIXME: explain what _version and ui are used for or leave them out, if unnecessary here]
Required minimal workflow
a walk-through
Preparing the plugin code
Provide translation configuration
Add some lines to setup.cfg
or, if it doesn't exist by now, create it with the following content:
[extract_messages] add_comments = TRANSLATOR: msgid_bugs_address = output_file = foo/locale/messages.pot keywords = _ ngettext:1,2 N_ tag_ width = 72 [init_catalog] input_file = foo/locale/messages.pot output_dir = foo/locale domain = foo [compile_catalog] directory = foo/locale domain = foo [update_catalog] input_file = foo/locale/messages.pot output_dir = foo/locale domain = foo
This will tell the translation helper programs where to look for and store message catalog files. Since this is a per plugin translation you need to change wherever it reads foo
in the example to the existing plugin directory that is a short form of plugin's name in most cases.
In the extract_messages
section there are other lines you may like to change. Starting with add_comments
there is the place to announce yourself as the translator by adding your name after the default TRANSLATOR:
label. To allow for direct feedback regarding your translation add a valid e-mail address or a mailing list dedicated to translation issues to msgid_bugs_address
.
Mark text for extraction
In python scripts you'll have to wrap text with the translation function _()
to get it handled by translation helper programs. Some code, that was
msg = 'This is a msg text.'
before, will read like
msg = _('This is a msg text.')
afterwards.
This is a somewhat time consuming task depending on the size of the plugin's code. If you initially fail to find all desired texts you may notice this by missing them from the message catalog later and come back to this step again. If the plugin maintainer is unaware of your l10n work or unwilling to support it and he adds more message without the translation function call, remember that you have to do the wrapping of these new texts too.
Message extraction for Genshi templates should be done auto-magically. However there is a markup available, to ensure extraction even from less common tags.
[FIXME: add details about msg extraction from templates and other files]
Register new files for packaging
To include the translated messages into the packaged plugin you need to add the path to the catalog files to package_data
in setup.py
.
New plugin version
The plugin will not work with any Trac version before 0.12dev, since import of the translation helper functions introduced for 0.12 will fail. It is possible to wrap the import with a try:
and define dummy functions in a corresponding except ImportError:
to allow the plugin to work with older versions of Trac, but there might already be a different version for 0.11 and 0.12, so this is not required in most cases.
All the work you did by now will go unnoticed, at least with regard to package naming. To help with identification of the new revision you should bump the plugin's version. This is done by changing the version/revision, typically in setup.cfg
or setup.py
.
Translation work
General advice from TracL10N on making good translation for Trac in general applies here too.
Compilation and testing
Compile the messages.po
catalog file with your translations into a machine readable messages.mo
file.
python ./setup.py compile_catalog -f -l de_DE
The argument -f
is needed to include even the msgid's marked 'fuzzy'. If you have prepared only one translated catalog the final language selection argument -l
and identifier string are superfluous. But as soon as there are several other translations that you don't care, it will help to select just your work for compilation.
Now finish your work by packaging the plugin. Make the python egg as usual:
python ./setup.py bdist_egg
Advanced stuff
Finally l10n
Related resources
Attachments (2)
-
itota-trac-subtickets-plugin-cb202be.tar.gz
(5.5 KB
) - added by 14 years ago.
local copy of TracSubtickets plugin source as reference for example
-
trac-subtickets-plugin_i18n-l10n.patch
(11.8 KB
) - added by 14 years ago.
i18n/l10n patch for TracSubtickets plugin maintained by Takashi Ito
Download all attachments as: .zip