Merge branch 'master' of ssh://git.ikiwiki.info

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

diff --git a/doc/plugins/po.mdwn b/doc/plugins/po.mdwn
index 9ae6d964a020b4f47b7b948ef3b724d2a6220de7..b701d3662e16e2ecb4f45f379169bf2cab2a2123 100644 (file)
--- a/doc/plugins/po.mdwn
+++ b/doc/plugins/po.mdwn
@@ -5,6 +5,10 @@ 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
 ============
 
 Introduction
 ============


@@ -12,9 +16,9 @@ Introduction
 A language is chosen as the "master" one, and any other supported
 language is a "slave" one.
 
 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. It does not have to be named
-a special way: migration from/to this plugin does not imply heavy
+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
 renaming work.
 
 Example: `bla/page.mdwn` is a "master" Markdown page written in


@@ -22,29 +26,38 @@ 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
 `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' => 'Français',
-                                'es' => 'Castellano',
-                                'de' => 'Deutsch',
-        }
+        po_slave_languages => [ 'fr|Français',
+                                'es|Español',
+                                'de|Deutsch',
+        ]

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


@@ -53,68 +66,45 @@ 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.
 
 translatable. It is a [[ikiwiki/PageSpec]], so you have lots of
 control over what kind of pages are translatable.
 

-The `*.LL.po` translations files are anyway not considered as being
-translatable, so you don't need to worry about excluding them manually
-from this [[ikiwiki/PageSpec]].
+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
 --------------
 
 
 Internal links
 --------------
 

-One can use the `po_link_to_` option in `ikiwiki.setup` to choose how
+### 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.
 
 internal links should be generated, depending on web server features
 and site-specific preferences.
 

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

 
 If `po_link_to` is unset, or set to `default`, ikiwiki's default
 
 If `po_link_to` is unset, or set to `default`, ikiwiki's default

-linking behavior is preserved: `\[[page]]` links to the master
+linking behavior is preserved: `\[[destpage]]` links to the master

 language's page.
 
 language's page.
 

-### 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:
-
-- `po_link_to => negotiated` provides no useful behavior if `usedirs`
-  is disabled; this option combination is neither implemented nor
-  allowed
-- `po_link_to => negotiated` provides no useful behavior if the web
-  server does not support Content Negotiation
-
-### Link to current language
+#### Link to current language

 
 

-If `po_link_to` is set to `current` and the destination page is either
-a translatable page or a translation, `\[[page]]` links to the current
-page's language, *i.e.*:
+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/page/index.LL.html` if `usedirs` is enabled
-- `foo/page.LL.html` if `usedirs` is disabled
+* `foo/destpage/index.LL.html` if `usedirs` is enabled
+* `foo/destpage.LL.html` if `usedirs` is disabled

 
 

+#### Link to negotiated language

 
 

-Templates
----------
+If `po_link_to` is set to `negotiated`, `\[[page]]` links to the
+negotiated preferred language, *i.e.* `foo/page/`.

 
 

-The `OTHERLANGUAGES` loop provides ways to display the existing
-translations and/or master page. One typically adds the following code
-to `templates/page.tmpl`:
-
-       <TMPL_IF NAME="OTHERLANGUAGES">
-       <div id="otherlanguages">
-         <ul>
-         <TMPL_LOOP NAME="OTHERLANGUAGES">
-           <li>
-             <a href="<TMPL_VAR NAME="URL">"
-                class="is_master_<TMPL_VAR NAME="MASTER">">
-             <TMPL_VAR NAME="LANGUAGE">
-           </a>
-           </li>
-         </TMPL_LOOP>
-         </ul>
-       </div>
-       </TMPL_IF>
+(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
 ==============
 
 Server support
 ==============


@@ -122,134 +112,141 @@ Server support
 Apache
 ------
 
 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.
+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, you should also set `DirectoryIndex index`.
+
+These settings are also recommended, in order to avoid serving up rss files
+as index pages:

 
 

-When `usedirs` is enabled, one has to set `DirectoryIndex index` for
-the wiki context.
+       AddType application/rss+xml;qs=0.8 .rss
+       AddType application/atom+xml;qs=0.8 .atom

 
 

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

 
 lighttpd
 --------
 
 
 lighttpd
 --------
 

-lighttpd unfortunately does not support content negotiation.
+Recent versions of lighttpd should be able to use
+`$HTTP["language"]` to configure the translated pages to be served.

 
 

-**FIXME**: does `mod_magnet` provide the functionality needed to
- emulate this?
+See [Lighttpd Issue](http://redmine.lighttpd.net/issues/show/1119)

 
 

+TODO: Example

 
 

-TODO
-====
+Usage
+=====

 
 

-Link relationships
-------------------
+Templates
+---------

 
 

-Should pages using the `OTHERLANGUAGES` template loop be declared as
-linking to the same page in other versions?
+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.

 
 

-View translation status
------------------------
+The `ISTRANSLATION` and `ISTRANSLATABLE` variables can be used to
+display things only on translatable or translation pages.

 
 

-One should be able to view some information about the translation
-completeness, either for a given page or for the whole wiki.
+The `LANG_CODE` and `LANG_NAME` variables can respectively be used to
+display the current page's language code and pretty name.

 
 

-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.
+### Display page's versions in other languages

 
 

-If it's not too heavy to compute, this status data may be made
-available in the `OTHERLANGUAGES` template loop; else, a dedicated
-loop would be needed.
+The `OTHERLANGUAGES` loop provides ways to display other languages'
+versions of the same page, and the translations' status.

 
 

-Automatic PO files update
--------------------------
+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):

 
 

-Committing changes to a "master" page:
+* `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

 
 

-1. updates the POT file and the PO files for the supported languages;
-   this is done in the `needsbuild` hook; **FIXME**: the updated PO
-   files must then be put under version control
+### Display the current translation status

 
 

-2. triggers a refresh of the corresponding HTML slave pages: this is
-   achieved by making any "slave" page dependent on the corresponding
-   "master" page, in the `needsbuild` hook.
+The `PERCENTTRANSLATED` variable is set to the translation
+completeness, expressed in percent, on "slave" pages. It is used by
+the default `templates/page.tmpl`.

 
 

-**FIXME** Also, when the plugin has just been enabled:
+Additional PageSpec tests
+-------------------------

 
 

-- all the needed POT and PO files have to be created
-- the PO files must be checked into version control
+This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some
+additional tests that are documented [[here|ikiwiki/pagespec/po]].

 
 

-UI consistency: rename "Edit" button on slave pages
----------------------------------------------------
+Automatic PO file update
+------------------------

 
 

-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* .
+Committing changes to a "master" page:

 
 

-Pages selection depending on language
--------------------------------------
+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.

 
 

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

 
 

-        \[[!map pages="dev/* and lang(LL)" feeds="no"]]
+Discussion pages and other sub-pages
+------------------------------------

 
 

-        \[[!map pages="dev/* and currentlang()" feeds="no"]]
+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.

 
 

-Translation quality assurance
------------------------------
+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.

 
 

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

 
 

-A new `cansave` type of hook would be needed to implement this.
+One can edit the PO files using ikiwiki's CGI (a message-by-message
+interface could also be implemented at some point).

 
 

-Note: committing to the underlying repository is a way to bypass
-this check.
+If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's
+preferred `$EDITOR`, without needing to be online.

 
 

-Translating online
-------------------
+Markup languages support
+------------------------

 
 

-As PO is a wiki page type, we already have an online PO editor, that
-is ikiwiki's 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:

 
 

-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.
+* [[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.

 
 

-Translating offline without VCS access
---------------------------------------
+Security
+========

 
 

-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:
+[[po/discussion]] contains a detailed security analysis of this plugin
+and its dependencies.

 
 

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

 
 

-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.
+BUGS
+====

 
 

-### Short-term workflow
+[[!inline pages="bugs/po:* and !bugs/done and !link(bugs/done) and !bugs/*/*"
+feeds=no actions=no archive=yes show=0]]

 
 

-A possible workaround is:
+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]]