357 lines
12 KiB
Markdown
357 lines
12 KiB
Markdown
[[!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`).
|
|
As detailed bellow in the security section, `po4a` is subject to
|
|
denial-of-service attacks before version 0.35.
|
|
|
|
[[!toc levels=2]]
|
|
|
|
Introduction
|
|
============
|
|
|
|
A language is chosen as the "master" one, and any other supported
|
|
language is a "slave" one.
|
|
|
|
A page written in the "master" language is a "master" page. It can be
|
|
of any page type supported by ikiwiki, except `po`. It does not have to be
|
|
named a special way: migration to this plugin does not imply any page
|
|
renaming work.
|
|
|
|
Example: `bla/page.mdwn` is a "master" Markdown page written in
|
|
English; if `usedirs` is enabled, it is rendered as
|
|
`bla/page/index.en.html`, else as `bla/page.en.html`.
|
|
|
|
Any translation of a "master" page into a "slave" language is called
|
|
a "slave" page; it is written in the gettext PO format. `po` is now
|
|
a page type supported by ikiwiki.
|
|
|
|
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.fr.html`, else as `bla/page.fr.html`
|
|
|
|
(In)Compatibility
|
|
=================
|
|
|
|
This plugin does not support the `indexpages` mode. If you don't know
|
|
what it is, you probably don't care.
|
|
|
|
|
|
Configuration
|
|
=============
|
|
|
|
Supported languages
|
|
-------------------
|
|
|
|
`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' => 'Français',
|
|
'es' => 'Español',
|
|
'de' => 'Deutsch',
|
|
}
|
|
|
|
Decide which pages are translatable
|
|
-----------------------------------
|
|
|
|
The `po_translatable_pages` setting configures what pages are
|
|
translatable. It is a [[ikiwiki/PageSpec]], so you have lots of
|
|
control over what kind of pages are translatable.
|
|
|
|
The `.po` files are not considered as being translatable, so you don't need to
|
|
worry about excluding them explicitly from this [[ikiwiki/PageSpec]].
|
|
|
|
Internal links
|
|
--------------
|
|
|
|
### Links targets
|
|
|
|
The `po_link_to` option in `ikiwiki.setup` is used to decide how
|
|
internal links should be generated, depending on web server features
|
|
and site-specific preferences.
|
|
|
|
#### Default linking behavior
|
|
|
|
If `po_link_to` is unset, or set to `default`, ikiwiki's default
|
|
linking behavior is preserved: `\[[destpage]]` links to the master
|
|
language's page.
|
|
|
|
#### Link to current language
|
|
|
|
If `po_link_to` is set to `current`, `\[[destpage]]` links to the
|
|
`destpage`'s version written in the current page's language, if
|
|
available, *i.e.*:
|
|
|
|
* `foo/destpage/index.LL.html` if `usedirs` is enabled
|
|
* `foo/destpage.LL.html` if `usedirs` is disabled
|
|
|
|
#### Link to negotiated language
|
|
|
|
If `po_link_to` is set to `negotiated`, `\[[page]]` links to the
|
|
negotiated preferred language, *i.e.* `foo/page/`.
|
|
|
|
(In)compatibility notes:
|
|
|
|
* if `usedirs` is disabled, it does not make sense to set `po_link_to`
|
|
to `negotiated`; this option combination is neither implemented
|
|
nor allowed.
|
|
* if the web server does not support Content Negotiation, setting
|
|
`po_link_to` to `negotiated` will produce a unusable website.
|
|
|
|
Server support
|
|
==============
|
|
|
|
Apache
|
|
------
|
|
|
|
Using Apache `mod_negotiation` makes it really easy to have Apache
|
|
serve any page in the client's preferred language, if available.
|
|
|
|
Add 'Options MultiViews' to the wiki directory's configuration in Apache.
|
|
|
|
When `usedirs` is enabled, one has to set `DirectoryIndex index` for
|
|
the wiki context.
|
|
|
|
Setting `DefaultLanguage LL` (replace `LL` with your default MIME
|
|
language code) for the wiki context can help to ensure
|
|
`bla/page/index.en.html` is served as `Content-Language: LL`.
|
|
|
|
For details, see [Apache's documentation](http://httpd.apache.org/docs/2.2/content-negotiation.html).
|
|
|
|
lighttpd
|
|
--------
|
|
|
|
Recent versions of lighttpd should be able to use
|
|
`$HTTP["language"]` to configure the translated pages to be served.
|
|
|
|
See [Lighttpd Issue](http://redmine.lighttpd.net/issues/show/1119)
|
|
|
|
TODO: Example
|
|
|
|
Usage
|
|
=====
|
|
|
|
Templates
|
|
---------
|
|
|
|
When `po_link_to` is not set to `negotiated`, one should replace some
|
|
occurrences of `BASEURL` with `HOMEPAGEURL` to get correct links to
|
|
the wiki homepage.
|
|
|
|
The `ISTRANSLATION` and `ISTRANSLATABLE` variables can be used to
|
|
display things only on translatable or translation pages.
|
|
|
|
### Display page's versions in other languages
|
|
|
|
The `OTHERLANGUAGES` loop provides ways to display other languages'
|
|
versions of the same page, and the translations' status.
|
|
|
|
An example of its use can be found in the default
|
|
`templates/page.tmpl`. In case you want to customize it, the following
|
|
variables are available inside the loop (for every page in):
|
|
|
|
* `URL` - url to the page
|
|
* `CODE` - two-letters language code
|
|
* `LANGUAGE` - language name (as defined in `po_slave_languages`)
|
|
* `MASTER` - is true (1) if, and only if the page is a "master" page
|
|
* `PERCENT` - for "slave" pages, is set to the translation completeness, in percents
|
|
|
|
### Display the current translation status
|
|
|
|
The `PERCENTTRANSLATED` variable is set to the translation
|
|
completeness, expressed in percent, on "slave" pages. It is used by
|
|
the default `templates/page.tmpl`.
|
|
|
|
Additional PageSpec tests
|
|
-------------------------
|
|
|
|
This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some
|
|
additional tests that are documented [[here|ikiwiki/pagespec/po]].
|
|
|
|
Automatic PO file update
|
|
------------------------
|
|
|
|
Committing changes to a "master" page:
|
|
|
|
1. updates the POT file and the PO files for the "slave" languages;
|
|
the updated PO files are then put under version control;
|
|
2. triggers a refresh of the corresponding HTML slave pages.
|
|
|
|
Also, when the plugin has just been enabled, or when a page has just
|
|
been declared as being translatable, the needed POT and PO files are
|
|
created, and the PO files are checked into version control.
|
|
|
|
Discussion pages and other sub-pages
|
|
------------------------------------
|
|
|
|
Discussion should happen in the language in which the pages are
|
|
written for real, *i.e.* the "master" one. If discussion pages are
|
|
enabled, "slave" pages therefore link to the "master" page's
|
|
discussion page.
|
|
|
|
Likewise, "slave" pages are not supposed to have sub-pages;
|
|
[[WikiLinks|wikilink]] that appear on a "slave" page therefore link to
|
|
the master page's sub-pages.
|
|
|
|
Translating
|
|
-----------
|
|
|
|
One can edit the PO files using ikiwiki's CGI (a message-by-message
|
|
interface could also be implemented at some point).
|
|
|
|
If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's
|
|
preferred `$EDITOR`, without needing to be online.
|
|
|
|
Markup languages support
|
|
------------------------
|
|
|
|
[[Markdown|mdwn]] and [[html]] are well supported. Some other markup
|
|
languages supported by ikiwiki mostly work, but some pieces of syntax
|
|
are not rendered correctly on the slave pages:
|
|
|
|
* [[reStructuredText|rst]]: anonymous hyperlinks and internal
|
|
cross-references
|
|
* [[wikitext]]: conversion of newlines to paragraphs
|
|
* [[creole]]: verbatim text is wrapped, tables are broken
|
|
* LaTeX: not supported yet; the dedicated po4a module
|
|
could be used to support it, but it would need a security audit
|
|
* other markup languages have not been tested.
|
|
|
|
Security
|
|
========
|
|
|
|
[[po/discussion]] contains a detailed security analysis of this plugin
|
|
and its dependencies.
|
|
|
|
When using po4a older than 0.35, it is recommended to uninstall
|
|
`Text::WrapI18N` (Debian package `libtext-wrapi18n-perl`), in order to
|
|
avoid a potential denial of service.
|
|
|
|
TODO
|
|
====
|
|
|
|
Better links
|
|
------------
|
|
|
|
Once the fix to
|
|
[[bugs/pagetitle_function_does_not_respect_meta_titles]] from
|
|
[[intrigeri]]'s `meta` branch is merged into ikiwiki upstream, the
|
|
generated links' text will be optionally based on the page titles set
|
|
with the [[meta|plugins/meta]] plugin, and will thus be translatable.
|
|
It will also allow displaying the translation status in links to slave
|
|
pages. Both were implemented, and reverted in commit
|
|
ea753782b222bf4ba2fb4683b6363afdd9055b64, which should be reverted
|
|
once [[intrigeri]]'s `meta` branch is merged.
|
|
|
|
An integration branch, called `meta-po`, merges [[intrigeri]]'s `po`
|
|
and `meta` branches, and thus has this additional features.
|
|
|
|
Language display order
|
|
----------------------
|
|
|
|
Jonas pointed out that one might want to control the order that links to
|
|
other languages are listed, for various reasons. Currently, there is no
|
|
order, as `po_slave_languages` is a hash. It would need to be converted
|
|
to an array to support this. (If twere done, twere best done quickly.)
|
|
--[[Joey]]
|
|
|
|
> Done in my po branch, preserving backward compatibility. Please
|
|
> review :) --[[intrigeri]]
|
|
|
|
>> Right, well my immediate concern is that using an array to hold
|
|
>> hash-like pairs is not very clear to the user. It will be displayed
|
|
>> in a confusing way by websetup; dumping a setup file will probably
|
|
>> also cause it to be formatted in a confusing way. And the code
|
|
>> seems to assume that the array length is even, and probably blows
|
|
>> up if it is not.. and the value is marked safe so websetup can be
|
|
>> used to modify it and break that way too. --[[Joey]]
|
|
|
|
Pagespecs
|
|
---------
|
|
|
|
I was suprised that, when using the map directive, a pagespec of "*"
|
|
listed all the translated pages as well as regular pages. That can
|
|
make a big difference to an existing wiki when po is turned on,
|
|
and seems generally not wanted.
|
|
(OTOH, you do want to match translated pages by
|
|
default when locking pages.) --[[Joey]]
|
|
|
|
Edit links on untranslated pages
|
|
--------------------------------
|
|
|
|
If a page is not translated yet, the "translated" version of it
|
|
displays wikilinks to other, existing (but not yet translated?)
|
|
pages as edit links, as if those pages do not exist.
|
|
|
|
That's really confusing, especially as clicking such a link
|
|
brings up an edit form to create a new, english page.
|
|
|
|
This is with po_link_to=current or negotiated. With default, it doesn't
|
|
happen..
|
|
|
|
Also, this may only happen if the page being linked to is coming from an
|
|
underlay, and the underlays lack translation to a given language.
|
|
--[[Joey]]
|
|
|
|
> Any simple testcase to reproduce it, please? I've never seen this
|
|
> happen yet. --[[intrigeri]]
|
|
|
|
>> Sure, go here <http://l10n.ikiwiki.info/smiley/smileys/index.sv.html>
|
|
>> (Currently 0% translateed) and see the 'WikiLink' link at the bottom,
|
|
>> which goes to <http://l10n.ikiwiki.info/ikiwiki.cgi?page=ikiwiki/wikilink&from=smiley/smileys&do=create>
|
|
>> Compare with eg, the 100% translated Dansk version, where
|
|
>> the WikiLink link links to the English WikiLink page. --[[Joey]]
|
|
|
|
Double commits of po files
|
|
--------------------------
|
|
|
|
When adding a new english page, the po files are created, committed,
|
|
and then committed again. The second commit makes this change:
|
|
|
|
-"Content-Type: text/plain; charset=utf-8\n"
|
|
-"Content-Transfer-Encoding: ENCODING"
|
|
+"Content-Type: text/plain; charset=UTF-8\n"
|
|
+"Content-Transfer-Encoding: ENCODING\n"
|
|
|
|
Same thing happens when a change to an existing page triggers a po file
|
|
update. --[[Joey]]
|
|
|
|
> * The s/utf-8/UTF-8 part is fixed in my po branch.
|
|
> * The ENCODING\n part is due to an inconsistency in po4a, which
|
|
> I've just send a patch for. --[[intrigeri]]
|
|
|
|
Ugly messages with empty files
|
|
------------------------------
|
|
|
|
If there are empty .mdwn files, the po plugin displays some ugly messages.
|
|
|
|
> This is due to a bug in po4a (not checking definedness of a
|
|
> variable). One-liner patch sent. --[[intrigeri]]
|
|
|
|
Translation of directives
|
|
-------------------------
|
|
|
|
If a translated page contains a directive, it may expand to some english
|
|
text, or text in whatever single language ikiwiki is configured to "speak".
|
|
|
|
Maybe there could be a way to switch ikiwiki to speaking another language
|
|
when building a non-english page? Then the directives would get translated.
|
|
|
|
(We also will need this in order to use translated templates, when they are
|
|
available.)
|
|
|
|
Documentation
|
|
-------------
|
|
|
|
Maybe write separate documentation depending on the people it targets:
|
|
translators, wiki administrators, hackers. This plugin may be complex
|
|
enough to deserve this.
|