po: check validity of po_slave_languages array.

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

diff --git a/doc/plugins/po.mdwn b/doc/plugins/po.mdwn
index 14d3ac65b7e672767092f7bab0f0e9d2165dd467..57f04a476094739efe23d9d04d6ef791699dfc1b 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
 ============


@@ -13,7 +17,7 @@ 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
 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, but PO. It does not have to 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.
 
 named a special way: migration to this plugin does not imply any page
 renaming work.
 


@@ -22,13 +26,19 @@ 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
 =============


@@ -44,10 +54,10 @@ Supported languages
 `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',
+        po_slave_languages => [ 'fr' => 'Français',
+                                'es' => 'Español',

                                 'de' => 'Deutsch',
                                 'de' => 'Deutsch',

-        }
+        ]

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


@@ -56,46 +66,46 @@ 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 PO translations files are anyway not considered as being
-translatable, so you don't need to worry about excluding them
-explicitly 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
 --------------
 

+### 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.
 
 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
+#### 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.
 
 
 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
+#### 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.*:
 
 
 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
+* `foo/destpage/index.LL.html` if `usedirs` is enabled
+* `foo/destpage.LL.html` if `usedirs` is disabled

 
 

-### Link to negotiated language
+#### 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 `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`
+* if `usedirs` is disabled, it does not make sense to set `po_link_to`

   to `negotiated`; this option combination is neither implemented
   nor allowed.
   to `negotiated`; this option combination is neither implemented
   nor allowed.

-- if the web server does not support Content Negotiation, setting
+* if the web server does not support Content Negotiation, setting

   `po_link_to` to `negotiated` will produce a unusable website.
 
   `po_link_to` to `negotiated` will produce a unusable website.
 

-

 Server support
 ==============
 
 Server support
 ==============
 


@@ -104,7 +114,8 @@ Apache
 
 Using Apache `mod_negotiation` makes it really easy to have Apache
 serve any page in the client's preferred language, if available.
 
 Using Apache `mod_negotiation` makes it really easy to have Apache
 serve any page in the client's preferred language, if available.

-This is the default Debian Apache configuration.
+
+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.
 
 When `usedirs` is enabled, one has to set `DirectoryIndex index` for
 the wiki context.


@@ -113,14 +124,17 @@ 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`.
 
 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
 --------
 
 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

 
 Usage
 =====
 
 Usage
 =====


@@ -128,6 +142,10 @@ Usage
 Templates
 ---------
 
 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.
 
 The `ISTRANSLATION` and `ISTRANSLATABLE` variables can be used to
 display things only on translatable or translation pages.
 


@@ -136,43 +154,21 @@ display things only on translatable or translation pages.
 The `OTHERLANGUAGES` loop provides ways to display other languages'
 versions of the same page, and the translations' status.
 
 The `OTHERLANGUAGES` loop provides ways to display other languages'
 versions of the same page, and the translations' status.
 

-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">"><TMPL_VAR NAME="LANGUAGE"></a>
-             <TMPL_UNLESS NAME="MASTER">
-               (<TMPL_VAR NAME="PERCENT">&nbsp;%)
-             </TMPL_UNLESS>
-           </li>
-         </TMPL_LOOP>
-         </ul>
-       </div>
-       </TMPL_IF>
-
-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
+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
 
 ### Display the current translation status
 
 The `PERCENTTRANSLATED` variable is set to the translation

-completeness, expressed in percent, on "slave" pages.
-
-One can use it this way:
-
-       <TMPL_IF NAME="ISTRANSLATION">
-       <div id="percenttranslated">
-         <TMPL_VAR NAME="PERCENTTRANSLATED">
-       </div>
-       </TMPL_IF>
+completeness, expressed in percent, on "slave" pages. It is used by
+the default `templates/page.tmpl`.

 
 Additional PageSpec tests
 -------------------------
 
 Additional PageSpec tests
 -------------------------


@@ -180,117 +176,181 @@ Additional PageSpec tests
 This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some
 additional tests that are documented [[here|ikiwiki/pagespec/po]].
 
 This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some
 additional tests that are documented [[here|ikiwiki/pagespec/po]].
 

-Automatic PO files update
--------------------------
+Automatic PO file update
+------------------------

 
 Committing changes to a "master" page:
 
 
 Committing changes to a "master" page:
 

-1. updates the POT file and the PO files for the supported languages
-   (this is done in the `needsbuild` hook); the updated PO files are
-   then put under version control
-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)
+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.
 
 
 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.
 

-TODO
-====
+Discussion pages and other sub-pages
+------------------------------------

 
 

-OTHERLANGUAGES dependencies
----------------------------
+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.

 
 

-Pages using `OTHERLANGUAGES` depend on any "master" and "slave" pages
-whose status is being displayed. It is supposed to trigger dependency
-loops, but no practical bugs were noticed yet.
+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.

 
 

-Should pages using the `OTHERLANGUAGES` template loop be declared as
-linking to the same page in other versions? To be rigorous, they
-should, but this may clutter the backlinks.
+Translating
+-----------

 
 

-Security checks
----------------
+One can edit the PO files using ikiwiki's CGI (a message-by-message
+interface could also be implemented at some point).

 
 

-- `refreshpofiles` uses `system()`, whose args have to be checked more
-  thoroughly to prevent any security issue (command injection, etc.).
-- `refreshpofiles` and `refreshpot` create new files; this may need
-  some checks, e.g. using `IkiWiki::prep_writefile()`
+If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's
+preferred `$EDITOR`, without needing to be online.

 
 

-gettext/po4a rough corners
---------------------------
+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
+====

 
 

-- fix the duplicated PO header mysterious bug
-- fix the "duplicate message definition" error when updating a PO
-  file; do PO files need normalizing? (may be a side effect of
-  previous bug)
-- fix infinite loop when synchronizing two ikiwiki (when checkouts
-  live in different directories): say bla.fr.po has been updated in
-  repo2; pulling repo2 from repo1 seems to trigger a PO update, that
-  changes bla.fr.po in repo1; then pushing repo1 to repo2 triggers
-  a PO update, that changes bla.fr.po in repo2; etc.; fixed in
-  `629968fc89bced6727981c0a1138072631751fee` ?
+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
+---------

 
 

-Misc. improvements
-------------------
+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]]

 
 

-### page titles
+Edit links on untranslated pages
+--------------------------------

 
 

-Use nice page titles from meta plugin in links, as inline already does.
+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. 

 
 

-### websetup
+That's really confusing, especially as clicking such a link
+brings up an edit form to create a new, english page.

 
 

-Which configuration settings are safe enough for websetup?
+This is with po_link_to=current or negotiated. With default, it doesn't
+happen.. 

 
 

-Translation quality assurance
------------------------------
+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]] 

 
 

-Modifying a PO file via the CGI must be forbidden if the new version
-is not a valid PO file. As a bonus, check that it provides a more
-complete translation than the existing one.
+> Any simple testcase to reproduce it, please? I've never seen this
+> happen yet. --[[intrigeri]]

 
 

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

 
 

-Note: committing to the underlying repository is a way to bypass
-this check.
+Double commits of po files
+--------------------------

 
 

-Translating online
-------------------
+When adding a new english page, the po files are created, committed,
+and then committed again. The second commit makes this change:

 
 

-As PO is a wiki page type, we already have an online PO editor, that
-is ikiwiki's CGI.
+       -"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"

 
 

-**FIXME** preview does not work for PO files.
+Same thing happens when a change to an existing page triggers a po file
+update. --[[Joey]] 

 
 

-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.
+> * 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]]

 
 

-Translating offline without VCS access
---------------------------------------
+Ugly messages with empty files
+------------------------------

 
 

-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 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
+-------------------------

 
 

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

 
 

-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.
+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.

 
 

-### Short-term workflow
+(We also will need this in order to use translated templates, when they are
+available.)

 
 

-A possible workaround is:
+Documentation
+-------------

 
 

-- 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
+Maybe write separate documentation depending on the people it targets:
+translators, wiki administrators, hackers. This plugin may be complex
+enough to deserve this.