X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/968106cc80c4f24ae02a3e54877939cd00e33258..884daeec1bdc5de71eb121b593f1c20aff44ed15:/doc/plugins/po.mdwn diff --git a/doc/plugins/po.mdwn b/doc/plugins/po.mdwn index fddfe5c41..53327c1da 100644 --- a/doc/plugins/po.mdwn +++ b/doc/plugins/po.mdwn @@ -5,31 +5,48 @@ 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, and is written in any supported format but PO. +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.html.en`, else as `bla/page.html.en`. +`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.html.fr`, else as `bla/page.html.fr` +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 ============= -`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: po_master_language => { 'code' => 'en', 'name' => 'English' } @@ -37,11 +54,57 @@ Configuration `po_slave_languages` is used to set the list of supported "slave" languages, such as: - po_slave_languages => { 'fr' => { 'name' => 'Français', }, - 'es' => { 'name' => 'Castellano', }, - 'de' => { 'name' => 'Deutsch', } + 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 ============== @@ -49,147 +112,282 @@ 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. +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) for the wiki context can be needed, to ensure -`bla/page/index.html.en` is served as `Content-Language: LL`. -**FIXME**: is it still needed with the new `.html.en` naming convention? +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 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 +===== -Display available translations ------------------------------- +Templates +--------- -The [[linguas|plugins/contrib/linguas]] plugin has some code that can -be used as a basis to display the existing translations, and allow to -navigate between them. +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. +### Display page's versions in other languages -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. +The `OTHERLANGUAGES` loop provides ways to display other languages' +versions of the same page, and the translations' status. -Decide which pages are translatable ------------------------------------ +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): -The subset of "master" pages subject to translation must be -configurable: +* `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 -- a `[[!translatable ]]` directive, when put on a page, makes it - translatable -- to set at once a bunch of pages as being translatable, use this - [[ikiwiki/directive]] with the `match=PageSpec` argument. +### Display the current translation status -Automatic PO files update +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 ------------------------- -Committing changes to a "master" page must: +This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some +additional tests that are documented [[here|ikiwiki/pagespec/po]]. + +Automatic PO file update +------------------------ -1. update the POT file and the PO files for the supported languages, - before putting them under version control -2. trigger a refresh of the corresponding HTML slave pages +Committing changes to a "master" page: -The former is to be done at a time when: +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. -- we know which "master" page was modified, and thus, which POT/PO - files have to be updated: the `needsbuild` hook is the first one to - run that provides us with the necessary information -- we can modify the list of pages needing a refresh; this is - `needsbuild` hook's job +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. -The latter can be implemented by making any "slave" page depend on the -corresponding "master" page. The `add_depends` function can achieve -this, if used in a **FIXME** hook. +Discussion pages and other sub-pages +------------------------------------ -UI consistency: rename "Edit" button on slave 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. -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* . +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. -Pages selection depending on language -------------------------------------- +Translating +----------- -To improve user navigation in a multi-lingual wiki, site developers -must be enabled to write: +One can edit the PO files using ikiwiki's CGI (a message-by-message +interface could also be implemented at some point). - \[[!map pages="dev/* and preferredlang()" feeds="no"]] +If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's +preferred `$EDITOR`, without needing to be online. - \[[!map pages="dev/* and currentlang()" feeds="no"]] +Markup languages support +------------------------ -Some new [[ikiwiki/pagespec]] functions have to be written. +[[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: -Translation quality assurance ------------------------------ +* [[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. -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. +Security +======== -A new `cansave` type of hook would be needed to implement this. +[[po/discussion]] contains a detailed security analysis of this plugin +and its dependencies. -Note: committing to the underlying repository is a way to bypass -this check. +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. -Translating online ------------------- +TODO +==== -As PO is a wiki page type, we already have an online PO editor, that -is ikiwiki's CGI. +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]] + +>>> I have added a sanity check for the even array problem. This was +>>> the easy part. +>>> +>>> About the hash-like vs. dump and websetup issue, +>>> I can think of a few solutions: +>>> +>>> - keep the current hash-like pairs and unmark this setting as safe +>>> for websetup: this does not solve the dump setup issue, though; +>>> - replace the array of pairs with an array of +>>> "LANGUAGECODE|LANGUAGENAME" elements, using a pipe or whatever +>>> separator seems adequate; +>>> - add support for ordered hashes to `$config`, websetup and +>>> dumpsetup, using Tie-IxHash or any similar module; +>>> - replace the array of hash-like pairs with an array of real +>>> pairs, such as `[ ['de', 'Deutsch'], ['fr', 'Français'] ]`; this +>>> brings once again the need for `$config` to support arrays of +>>> arrays, which I have already implemented in my mirrorlist branch +>>> (see [[todo/mirrorlist_with_per-mirror_usedirs_settings]] for +>>> details). +>>> +>>> Joey, which of these solutions do you prefer? Or another one? +>>> I tend to prefer the last one. --[[intrigeri]] + +>>>> I prefer the pipe separator, I think. I'm concerned that there is +>>>> no way to really sanely represent complex data structures in web +>>>> setup. --[[Joey]] + +Pagespecs +--------- + +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]] + +Edit links on untranslated pages +-------------------------------- + +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]] + +Double commits of po files +-------------------------- + +When adding a new english page, the po files are created, committed, +and then committed again. The second commit makes this change: + + -"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" + +Same thing happens when a change to an existing page triggers a po file +update. --[[Joey]] + +> * 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]] + +New pages not translatable +-------------------------- + +Today I added a new English page to l10n.ikiwiki.info. When I saved, +the page did not have the translation links at the top. I waited until +the po plugin had, in the background, created the po files, and refreshed; +still did not see the translation links. Only when I touched the page +source and refreshed did it finally add the translation links. +I can reproduce this bug in a test site. --[[Joey]] + +Ugly messages with empty files +------------------------------ -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. +If there are empty .mdwn files, the po plugin displays some ugly messages. -Translating offline without VCS access --------------------------------------- +> This is due to a bug in po4a (not checking definedness of a +> variable). One-liner patch sent. --[[intrigeri]] -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: +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.