[[!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 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? Usage ===== Templates --------- ### 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. One typically adds the following code to `templates/page.tmpl`:
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. Additional PageSpec tests ------------------------- This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some additional tests that are documented [[here|ikiwiki/pagespec/po]]. TODO ==== OTHERLANGUAGES dependencies --------------------------- Pages using `OTHERLANGUAGES` must depend on any "master" and "slave" pages whose status is being displayed. It will trigger dependency loops; how to sort this out? 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. Automatic PO files update ------------------------- 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; **FIXME**: the updated PO files must then be 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. **FIXME** Also, when the plugin has just been enabled, or when a page has just been declared as being translatable: - all the needed POT and PO files have to be created - the PO files must be checked into version control **FIXME** `refreshpofiles` uses `system()`, whose args have to be checked more thoroughly to prevent any security issue (command injection, etc.). 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* . 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