[[!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`). 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. It does not have to be named a special way: migration from/to this plugin does not imply heavy 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` Configuration ============= `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' => 'Castellano', '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 `*.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]]. Internal links -------------- One can use the `po_link_to_` option in `ikiwiki.setup` to choose 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: `\[[page]]` links to the master 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 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.*: - `foo/page/index.LL.html` if `usedirs` is enabled - `foo/page.LL.html` if `usedirs` is disabled Templates --------- The `OTHERLANGUAGES` loop provides ways to display the existing translations and/or master page. One typically adds the following code to `templates/page.tmpl`:
Server support ============== 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. When `usedirs` is enabled, one has to set `DirectoryIndex index` for the wiki context. 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? lighttpd -------- lighttpd unfortunately does not support content negotiation. **FIXME**: does `mod_magnet` provide the functionality needed to emulate this? TODO ==== Link relationships ------------------ Should pages using the `OTHERLANGUAGES` template loop be declared as linking to the same page in other versions? View translation status ----------------------- One should be able to view some information about the translation completeness, either for a given page or for the whole wiki. 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. 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. Automatic PO files update ------------------------- Committing changes to a "master" page must: 1. update the POT file and the PO files for the supported languages; this is done in the `needsbuild` hook; the updated PO files must then be put under version control 2. trigger 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. Also, when the plugin has just been enabled, all the needed POT and PO files have to be created. UI consistency: rename "Edit" button on slave pages --------------------------------------------------- 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* . Pages selection depending on language ------------------------------------- To improve user navigation in a multi-lingual wiki, site developers must be enabled to write: \[[!map pages="dev/* and lang(LL)" feeds="no"]] \[[!map pages="dev/* and currentlang()" feeds="no"]] Translation quality assurance ----------------------------- 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. A new `cansave` type of hook would be needed to implement this. Note: committing to the underlying repository is a way to bypass this check. Translating online ------------------ As PO is a wiki page type, we already have an online PO editor, that is ikiwiki's CGI. 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 offline without VCS access -------------------------------------- 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: - download the page's PO file - use any PO editor to update the translation - upload the updated PO file 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. ### Short-term workflow A possible workaround is: - 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