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[git.ikiwiki.info.git] / doc / plugins / po.mdwn

diff --git a/doc/plugins/po.mdwn b/doc/plugins/po.mdwn
index 9e9ba1fd841631ce6204a834229ca908050d05cf..f91e44ea317d1b0bd9655f545541d1d55ad0aa66 100644 (file)
--- a/doc/plugins/po.mdwn
+++ b/doc/plugins/po.mdwn
@@ -5,212 +5,245 @@ 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`).
 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
 
 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, and is written in any supported format but PO.
+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
 
 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 "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`
 
 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
 =============
 
 
 Configuration
 =============
 

-`po_master_language` is used to set the master language in
+Supported languages
+-------------------
+
+`po_master_language` is used to set the "master" language in

 `ikiwiki.setup`, such as:
 
 `ikiwiki.setup`, such as:
 

-        po_master_language => { 'code' => 'en', 'name' => 'English' }
+        po_master_language => 'en|English'

 
 `po_slave_languages` is used to set the list of supported "slave"
 languages, such as:
 
 
 `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', }
-        }
+        po_slave_languages => [ 'fr|Français',
+                                'es|Español',
+                                'de|Deutsch',
+        ]

 
 

+Decide which pages are translatable
+-----------------------------------

 
 

-Server support
-==============
+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.

 
 

-Apache
-------
+The `.po` files are not considered as being translatable, so you don't need to
+worry about excluding them explicitly from this [[ikiwiki/PageSpec]].

 
 

-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.
+Internal links
+--------------

 
 

-When `usedirs` is enabled, one has to set `DirectoryIndex index` for
-the wiki context.
+### Links targets

 
 

-Setting `DefaultLanguage LL` (replace `LL` with your default MIME
-language) for the wiki context can be needed, to ensure
-`bla/page/index.en.html` is served as `Content-Language: LL`.
-**FIXME**: is it still needed with the new `.en.html` naming convention?
+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.

 
 

-lighttpd
---------
+#### Default linking behavior

 
 

-lighttpd unfortunately does not support content negotiation.
+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.

 
 

-**FIXME**: does `mod_magnet` provide the functionality needed to
- emulate this?
+#### 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.*:

 
 

-TODO
-====
+* `foo/destpage/index.LL.html` if `usedirs` is enabled
+* `foo/destpage.LL.html` if `usedirs` is disabled

 
 

-Links
------
+#### Link to negotiated language

 
 

-Choice between two behaviors must be possible in `ikiwiki.setup`;
-a `po_link_to_current_language` option must allow switching
-between them.
+If `po_link_to` is set to `negotiated`, `\[[page]]` links to the
+negotiated preferred language, *i.e.* `foo/page/`.

 
 

-If `po_link_to_current_language` is disabled, `[[page]]` links to the
-negotiated preferred language, i.e.:
+(In)compatibility notes:

 
 

-- `usedirs` enabled: `bla/page/`
-- `usedirs` disabled: `bla/page`
+* 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.

 
 

-This obviously does not work in case Content Negotiation is not
-supported by the web server, hence one can enable
-`po_link_to_current_language` to make `[[page]]` link to the current
-page's language, i.e.:
+Server support
+==============

 
 

-- `usedirs` enabled: `bla/page/index.LL.html`
-- `usedirs` disabled: `bla/page.LL.html`
+Apache
+------

 
 

-**FIXME**: should `po_link_to_current_language` be enabled by default?
+Using Apache `mod_negotiation` makes it really easy to have Apache
+serve any page in the client's preferred language, if available.

 
 

-Display available translations
-------------------------------
+Add 'Options MultiViews' to the wiki directory's configuration in Apache.

 
 

-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.
+When `usedirs` is enabled, you should also set `DirectoryIndex index`.

 
 

-View translation status
------------------------
+These settings are also recommended, in order to avoid serving up rss files
+as index pages:

 
 

-One should be able to view some information about the translation
-completeness, either for a given page or for the whole wiki.
+       AddType application/rss+xml;qs=0.8 .rss
+       AddType application/atom+xml;qs=0.8 .atom

 
 

-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.
+For details, see [Apache's documentation](http://httpd.apache.org/docs/2.2/content-negotiation.html).

 
 

-Decide which pages are translatable
------------------------------------
+lighttpd
+--------

 
 

-The subset of "master" pages subject to translation must be
-configurable:
+Recent versions of lighttpd should be able to use
+`$HTTP["language"]` to configure the translated pages to be served.

 
 

-- a `[[!translatable ]]` directive, when put on a page, makes it
-  translatable
-- to set at once a bunch of pages as being translatable, use this
-  [[ikiwiki/directive]] with the `match=PageSpec` argument.
+See [Lighttpd Issue](http://redmine.lighttpd.net/issues/show/1119)

 
 

-Automatic PO files update
--------------------------
+TODO: Example
+
+Usage
+=====

 
 

-Committing changes to a "master" page must:
+Templates
+---------

 
 

-1. update the POT file and the PO files for the supported languages,
-   before putting them under version control
-2. trigger a refresh of the corresponding HTML slave pages
+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 former is to be done at a time when:
+The `ISTRANSLATION` and `ISTRANSLATABLE` variables can be used to
+display things only on translatable or translation pages.

 
 

-- we know which "master" page was modified, and thus, which POT/PO
-  files have to be updated: the `needsbuild` hook is the first one to
-  run that provides us with the necessary information
-- we can modify the list of pages needing a refresh; this is
-  `needsbuild` hook's job
+### Display page's versions in other languages

 
 

-The latter can be implemented by making any "slave" page depend on the
-corresponding "master" page. The `add_depends` function can achieve
-this, if used in a **FIXME** hook.
+The `OTHERLANGUAGES` loop provides ways to display other languages'
+versions of the same page, and the translations' status.

 
 

-UI consistency: rename "Edit" button on slave pages
----------------------------------------------------
+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):

 
 

-It may be surprising to some, after having pressed *Edit* on a wiki
-page, to end up editing a strange looking PO file. The *Edit* button
-displayed on "slave" pages must therefore be renamed *Improve
-translation* .
+* `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

 
 

-Pages selection depending on language
--------------------------------------
+### Display the current translation status

 
 

-To improve user navigation in a multi-lingual wiki, site developers
-must be enabled to write:
+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
+-------------------------

 
 

-        \[[!map pages="dev/* and lang(LL)" feeds="no"]]
+This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some
+additional tests that are documented [[here|ikiwiki/pagespec/po]].

 
 

-        \[[!map pages="dev/* and currentlang()" feeds="no"]]
+Automatic PO file update
+------------------------

 
 

-Translation quality assurance
------------------------------
+Committing changes to a "master" page:

 
 

-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.
+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.

 
 

-A new `cansave` type of hook would be needed to implement this.
+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.

 
 

-Note: committing to the underlying repository is a way to bypass
-this check.
+Discussion pages and other sub-pages
+------------------------------------

 
 

-Translating online
-------------------
+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.

 
 

-As PO is a wiki page type, we already have an online PO editor, that
-is ikiwiki's CGI.
+Likewise, "slave" pages are not supposed to have sub-pages;
+[[WikiLinks|ikiwiki/wikilink]] that appear on a "slave" page therefore link to
+the master page's sub-pages.

 
 

-A message-by-message interface could also be implemented at some
-point; a nice way to do offline translation work (without VCS access)
-still has to be offered, though.
+Translating
+-----------

 
 

-Translating offline without VCS access
---------------------------------------
+One can edit the PO files using ikiwiki's CGI (a message-by-message
+interface could also be implemented at some point).

 
 

-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:
+If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's
+preferred `$EDITOR`, without needing to be online.

 
 

-- download the page's PO file
-- use any PO editor to update the translation
-- upload the updated PO file
+Markup languages support
+------------------------

 
 

-Implementation note: a generic mechanism to upload a page's source is
-needed: it's only an alternative way to allow saving a the modified
-page's source with the CGI.
+[[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:

 
 

-### Short-term workflow
+* [[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.

 
 

-A possible workaround is:
+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.
+
+BUGS
+====
+
+[[!inline pages="bugs/po:* and !bugs/done and !link(bugs/done) and !bugs/*/*"
+feeds=no actions=no archive=yes show=0]]
+
+TODO
+====

 
 

-- 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.
-- edit the local file in any PO editor
-- pretend to edit the PO file online
-- paste the modified local file's content into the edit textarea
-- save
+[[!inline pages="todo/po:* and !todo/done and !link(todo/done) and !todo/*/*"
+feeds=no actions=no archive=yes show=0]]