[[!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|ikiwiki/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. BUGS ==== [[!inline pages="bugs/po:* and !bugs/done and !link(bugs/done) and !bugs/*/*" feeds=no actions=no archive=yes show=0]] TODO ==== [[!inline pages="todo/po:* and !todo/done and !link(todo/done) and !todo/*/*" feeds=no actions=no archive=yes show=0]] l10n wiki misconfiguration -------------------------- 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 >> (Currently 0% translateed) and see the 'WikiLink' link at the bottom, >> which goes to >> Compare with eg, the 100% translated Dansk version, where >> the WikiLink link links to the English WikiLink page. --[[Joey]] >>> Seems not related to the page/string translation status: the 0% >>> translated Spanish version has the correct link, just like the >>> Dansk version => I'm changing the bug title accordingly. >>> >>> I tested forcing the sv html page to be rebuilt by translating a >>> string in it, it did not fix the bug. I did the same for the >>> Spanish page, it did not introduce the bug. So this is really >>> weird. >>> >>> The smiley underlay seems to be the only place where the wrong >>> thing happens: the basewiki underlay has similar examples >>> that do not exhibit this bug. An underlay linking to another might >>> be necessary to reproduce it. Going to dig deeper. --[[intrigeri]] >>>> After a few hours lost in the Perl debugger, I think I have found >>>> the root cause of the problem: in l10n wiki's configured >>>> `underlaydir`, the basewiki is present in every slave language >>>> that is enabled for this wiki *but* Swedish. With such a >>>> configuration, the `ikiwiki/wikilink` page indeed does not exist >>>> in Swedish language: no `ikiwiki/wikilink.sv.po` can be found >>>> where ikiwiki is looking. Have a look to >>>> , the basewiki is not >>>> available in Swedish language on this wiki. So this is not a po >>>> bug, but a configuration or directories layout issue. This is >>>> solved by adding the Swedish basewiki to the underlay dir, which >>>> is I guess not a possibility in the l10n wiki context. I guess >>>> this could be solved by adding `SRCDIR/basewiki` as an underlay >>>> to your l10n wiki configuration, possibly using the >>>> `add_underlays` configuration directive. --[[intrigeri]]