[[!template id=plugin name=po core=0 author="[[intrigeri]]"]]
[[!tag type/format]]
This plugin adds support for multi-lingual wikis, translated with
gettext, using [po4a|http://po4a.alioth.debian.org/].
It depends on the Perl Locale::Po4a::Po
library (apt-get install po4a
).
Introduction
A language is decided to be the "master" one, and any other supported
language is a "slave" one. A page written in the "master" language is
a "master" page, and is written in any supported format but PO.
Example: bla/page.mdwn
is a "master" Markdown page written in
English; if usedirs
is enabled, it is rendered as
bla/page/index.html.en
, else as bla/page.html.en
.
Translations of a "master" page into a "slave" language are called
"slave" pages, and is a in gettext PO format. PO is thus promoted to
the wiki page type status.
Example: bla/page.fr.po
is the PO "message catalog" used to
translate bla/page.mdwn
into French; if usedirs
is enabled, it is
rendered as bla/page/index.html.fr
, else as bla/page.html.fr
Configuration
po_master_language
is used to set the master language in
ikiwiki.setup
, such as:
po_master_language => { 'code' => 'en', 'name' => 'English' }
po_slave_languages
is used to set the list of supported "slave"
languages, such as:
po_slave_languages => { 'fr' => { 'name' => 'Français', },
'es' => { 'name' => 'Castellano', },
'de' => { 'name' => 'Deutsch', },
},
Server support
Apache
Using mod_negotiation
makes it really easy to have Apache serve the
page in the client's preferred language, if available. This is the
default Debian Apache configuration.
When usedirs
is enabled, one has to set DirectoryIndex index
for
the wiki context.
Setting DefaultLanguage LL
(replace LL
with your default MIME
language) for the wiki context can be needed, to ensure
bla/page/index.html.en
is served as Content-Language: LL
.
FIXME: is it still needed with the new .html.en
naming convention?
lighttpd
lighttpd unfortunately does not support content negotiation.
TODO
Display available translations
The [[linguas|plugins/contrib/linguas]] plugin has some code that can
be used as a basis to display the existing translations, and allow to
navigate between them.
View translation status
One should be able to view some freshness information about the
translation status, either for a given page or for the whole wiki.
This should not be too hard using gettext tools. If this is
implemented as a
[[HTML::Template|http://search.cpan.org/search?mode=dist&query=HTML%3A%3ATemplate]]
loop, a page using it should depend on any "master" and "slave" pages
whose status is being displayed.
Decide which pages are translatable
The subset of ("master") pages supporting translation must be
configurable:
- a
[[!translatable ]]
directive, when put on a page, makes it
translatable
- this [[ikiwiki/directive]] can be used with an optional
match=PageSpec
argument, to render translatable a bunch of pages at once
Automatic PO files update
Committing changes to a "master" page must:
- update the POT file, the PO files for the supported languages, and
put them under version control
- trigger a refresh of the corresponding HTML slave pages
The former can be implemented as a needsbuild
hook, which is the
first type of hook to run after the list of files that need to be
built is known: that is, at a time when we know which "master" page
was modified, and thus, which POT/PO files have to be updated.
The latter can be implemented by making any "slave" page depend on the
corresponding "master" page. The add_depends
function can achieved
this, if used in a FIXME hook.
UI consistency: rename "Edit" button on slave pages
It may be surprising to some, after having pressed Edit on a wiki
page, to end up editing a strange PO file. The Edit button must then
be be renamed to Improve translation on "slave" pages.
Translation quality assurance
Modifying a PO file via the CGI must only be allowed if the new
version is a valid PO file. As a bonus, check that it provides a more
complete translation than the existing one.
A new cansave
type of hook would be needed to implement this.
Note: committing to the underlying repository is a way to bypass
this check.
Translating online
As PO is a wiki page type, we already have an online PO editor, that
is ikiwiki's CGI.
A message-by-message interface could be implemented later, providing
a nice way to translate offline (without VCS access) is provided.
Translating offline without VCS access
The following workflow should be made possible for translators without
VCS access who need to edit the PO files in another editor than a web
browser:
- download the PO file for the page
- use any PO editor to update the translation
- upload the updated PO file
A generic mechanism to download and upload a page's source is needed.
It's only an alternative way to do Edit/edit/Save.
Short-term workflow
- pretend to edit the PO file online
- copy the PO file content from the textarea
- cancel the edit
- paste the content into a local file.