View source for Page Translation Explained

'''What.''' The page translation feature allows controlled translation of wiki pages into other languages.
That means that the content of each translation will be, usually, equal to the source page.
This is opposed to, for example, the different language version of articles in different Wikipedias, which are fully independent of each other. 
It is assumed that pages are only translated from one primary language to other languages, but translators can take advantage of translations in other languages too if they exist.

'''Why.''' Without any help, translating more than a few pages into other languages becomes a time-waster at best, an unmaintainable mess at worst.
With the page translation feature you can avoid the mess and bring structure to the translation process. The core idea is that the source text is segmented into smaller units, each of which will be translated individually. When the source text is segmented into units, all changes can be isolated and translators only need to update the translations of units which have had changes in source text. This also enables translators to work on units of manageable size and share the work between multiple translators or continue the translation in later sessions, because they don't need to do all at once.

'''Who.''' This page elaborates on the [[Special:MyLanguage/Help:Extension:Translate/Page_translation_example|page translation tutorial]] by providing deeper insight on how the system works, and suggests best practices for a wide variety of cases. This page is intended for page translation administrators and generally for everyone who edits the source text of translatable pages, even if they don't have the access to the administrative features of approving changes for translation.

<span id=overview></span>
== Life of a translatable page ==

'''Roles.''' Multiple people are involved in the process of writing and translating a wiki page: the initial writer creates a page, someone corrects spelling errors, a page translation administrator marks the page for translation, translators translate, someone makes changes to the page, a page translation administrator marks those changes for translation and translators update translations. Those roles may overlap more or less, but the ultimate responsibility for a hassle-free translation is left for the page translation administrator. The administrator decides when the page is ready for translation the first time, ensures that the segmentation serves a purpose and approves (or corrects) changes.

'''Preparation.''' To have something translated you have to write it first. If you already have done translation without the Translate extension, see below the [[#migration|section about migrating translations]]. If you want lots of translation and quickly, it is crucial for the source text to be in good shape. Before marking page for translation, ask someone else to proofread it and if possible ask a language specialist to make the text more clear and concise. Difficult vocabulary and hard to understand sentences are a show stopper to many volunteer translations. Markup too can cause problems for translators, but as a translation administrator you can avoid those issues, see below the [[#segmentation|section about handling markup]]. Naturally the changes you make to the source text of translation force update of all existing translations, so it is better to wait until the contents of the page have stabilized. On the other hand, changes do happen, and the system handles that well, so check out the [[#changes|section about handling changes]] below.

'''Tagging.''' When the text is otherwise ready for translation, anyone can mark the translatable parts by wrapping them inside &lt;translate> tags and adding the &lt;languages /> bar to the page. The latter adds a list of all translations of the page, with their completion and up-to-date percentages. There is no other indication that translations exist. See below [[#markup|how to actually do the tagging]]. The system will detect when the tags are placed on the translatable page, and the page will have a link to mark it for translation. It will also complain and prevent saving if you for example forgot to add a closing tag. The translatable page will also be listed on Special:PageTranslation as ''ready for marking''.

'''Marking.''' After the tagging, a translation administrator marks the page for translation. The interface is explained in [[Special:MyLanguage/Help:Extension:Translate/Page translation example|Page translation example]]. The translation administrator's responsibility is to make sure that the segmentation makes sense and that tagging has been proper. The page can be marked again if it has changed in the meanwhile. See below [[#changes|how to make changes that cause minimal disruptions]]. The marking of the page starts a background process that uses MediaWiki's [[Manual:Job queue|job queue]]. This process goes over each translation page and regenerates it: changes in the translation page template will be reflected and outdated translations will be replaced temporarily with the original source text. On the contrary, the translation interface is updated immediately.

'''Changes.''' Users can continue making changes to the translatable page source. The changes will be visible to users viewing the page in the source language, but translations are done against the translation units extracted from the last version of the translatable page which has been marked for translation: the translation pages are reported to be 100 % up to date if all translation units have been translated, even if the source page has new changes. You can easily see whether there are unmarked changes when viewing the translatable page in the source language: there is a notice at the top which says that you can translate this page and also links to changes if there are any.

'''Source language'''. There is also a translation page with the language code of the source language: it doesn't contain the extra tags and other markup related to page translation which are used in the translatable page source. This page is not linked from the interface, but it is handy for example when you want to transclude the page (typically for translatable templates) or export it.

'''Closed translation requests.''' Some translatable pages have a content that is only interesting for a certain period of time. For example announcements and regular status updates, like the Wikimedia monthly highlights. You can keep those pages around with translations, but hide them from the translation interface. This does not prevent further translations to the pages, but it greatly reduces the chance that a user accidentally starts translating the page. Discouraging and its reversion are done from Special:PageTranslation.

'''Prioritizing languages.''' You can also define a list of languages that you specifically want translations into; leaving the language list empty is interpreted as all languages allowed. The page will behave like a discouraged page (see previous paragraph) for the languages not in the priority list and, when translating into them, translators will be given a notice. You can also prevent the translation in other languages, say if translations are actually used elsewhere and you won't be able to use them but in some languages. 

'''Grouping.''' It is possible to group related pages together. These groups work like all the other message groups. They have their own statistics and contain all the messages of the subgroups: in this case translatable pages. This functionality is currently in Special:AggregateGroups. Aggregate message groups are collapsed by default in Special:LanguageStats in the group selector at Special:Translate.

'''Moving.''' You can move translatable pages as you would move any other page. When moving you can choose whether you want to move any non-translation subpages too. The move uses a background job to move the many related pages. While the move is in progress, it is not possible to translate the page. Completion is noted in the page translation log.

'''Deleting.''' Like move, deletion is accessed from the normal place. You can either delete the whole translatable page, or just one translation of it. To delete one translation, go to the translation page and then access delete. As in move, a background process will delete the pages over time. Deletion will also delete the related translation unit pages. Completion is noted in the page translation log.

'''Reverting.''' Similarly, reverting incorrect edits works as usual (including rollback button): you only have to edit the affected translation unit and the translation page will be updated as well. To find the edit to the translation unit from the edit to the translation page, just click the "{{int:contribslink}}" link for the editor and look for an edit at a similar time.

'''Protecting.''' It is possible to [[Special:MyLanguage/Help:Protected_pages|protect]] the translatable page. Translation pages cannot be protected, nor does the protection of the translatable page extend to them. To prevent further edits to translations, you should add the source language as only priority language and disable translations to other languages, see ''prioritizing languages'' above. Together these two actions effectively prevent changes to both the source page and translation pages with its translation unit pages. It is possible to protect individual translation unit pages, though it is not advisable.

'''Removal from translation'''. It is also possible to unmark a page for translation. First you need to remove all translate tags from the page. Then you can use Special:PageTranslation or follow the link in the top of translatable page to remove it from translation. This will remove any structure related to page translation, but leave all the existing pages in place, freely editable. This action is not recommended.

== Anatomy of a translatable page ==

The translation of a translatable page will produce many pages, which all together compose the translatable page in the broadest sense: their title is determined by the title of the translatable <code>Page</code>:

* <code>Page</code> (the source page)
* <code>Page/<language code></code> (the translation pages, plus a copy of the source page without markup)
* <code>Translations:Page/<translation unit identifier>/<language code></code> (all the translation unit pages)

In addition to this, there are the translation page template and the sources of translation units, extracted from the source page and stored in the database. The system keeps track of which versions of the source page contain translation tags and which version of them have been marked for translation.

Every time a translation unit page is updated, the system will also regenerate the corresponding translation page. This will result in two edits. The translation unit page edit is hidden by default in recent changes and can be shown by choosing ''show translations'' from the translation filter. Any action other than editing (like deleting and moving) the translation unit pages will not trigger the regeneration of the corresponding translation page.

<span id=segmentation></span>
== Segmentation ==

General principles:

# All text intended for translation must be wrapped inside translate tags. There can be multiple pairs of tags in one page.
# Everything outside those tags will not change in any translation page. This static text, together with the placeholders which mark the place where the translation of each translation unit will be substituted, is called the translation page template.
# Too much markup in the text makes it difficult for translators to translate. Use more fine grained placing of translate tags when there are lots of markup.
# The text inside translate tags is split into translation units where there is one or more empty lines between them (two or more newlines).

'''Restrictions.''' The page translation feature places some restrictions on the text. There should not be any markup that spans over two or more translation units. In other words, each paragraph should be self-contained. This is currently not enforced in the software, but violating it will cause invalid rendering of the page, the severity depending on whether MediaWiki itself is able to fix the resulting html output or not.

'''Parsing order.''' Beware, the translate tags work differently from other tags, because they do not go through the parser. This should not cause problems usually, but may if you are trying something fancy. In more detail, they are parsed before any other tags like &lt;pre> or &lt;source>, with the exception of &lt;nowiki> which is recognized by the Translate extension in some circumstances (such as rendering a page) but not in others (such as generating the list on Special:PageTranslation of pages containing &lt;translate>). If you want to have the literal expression "&lt;translate>" in the source text, you should escape it like "&amp;lt;translate>".

'''Tag placing.''' If possible, try to put the tags on their own lines, with no empty lines between the content and the tags. Sometimes this is not possible, for example if you want to translate some content surrounded by the markup, but not the markup itself. This is fine too, for example:

<pre>
{{Template|&lt;translate>Some localised parameter&lt;/translate>}}
</pre>
To make this work, the extension has a simple whitespace handling: whitespace is preserved, except if an opening or closing translate tag is the only thing on a line. In that case the newline after the opening tag or before the closing tag is eaten. This means that they don't cause extra space in the rendered version of the page.

'''Variables.''' It is possible to use variables similar to template variables. The syntax for this is <tt>&lt;tvar|name></tt>''contents''<tt></></tt>. For translators these will show up only as <code>$name</code>, and in translation pages will automatically be replaced by the value defined in the translatable page (so they are global "constants" across all its translation pages). Variables can be used to hide untranslatable content in the middle of a translation unit. It also works for things like numbers that need to be updated often. You can update the number in all translations by changing the number in the translatable page source and re-marking the page. You do not need to invalidate translations, because the number is not part of the translation unit pages.

<span id=markup></span>
== Markup examples ==

Below are listed some alternatives and suggested ways to handle different kinds of wiki markup.

{| class="prettytable" style="font-size:.9em;"
| '''Categories'''
| Categories can be added in two ways: in the translation page template or in one of the translation units. If you have the categories in the translation page template, all translations will end up in the same category. If you have categories inside translation units, you should teach the users a naming scheme. On the right we show two possible schemes which are independent of the technical means to adopt them.
|
'''No translation''': Category:Cars

* All translations in same category (good if only few languages, bad if many).
* Category name not translated (can be put as is in the translation template).

'''Translation by adding language suffix''': Category:Cars/fi (recommended but unsupported)

* Category page name not translated (just like the page names).
* One category for each language.
* Page translation could be used for the category itself: the categories would be linked together and the headers would be translated (but not the name of the category in links and such).
* This option is not yet supported out of the box by the Translate extension. You need to either instruct your translators to add the language code suffix to the category markup in the translation, or leave the category out of translation and write your own templates which add the language code automatically.<br/>
There are some such templates available on the wikis which use the Translate extension, but they won't be dealt with here. Additionally, categories' description pages will have to be created manually and translated with a non-Translate system, because the extension is not able to deal with them.
<!--
This is potentially solved with display title improvements someday, bug 29975
'''Full translation with language suffix''': Category:Autot/fi
* You need the language suffix or multiple languages will end up using the same category if the translation is identical
* No possibility to use page translation on the category page itself
* Categories not linked to each other
* One category for each language
* Category page names are ugly but translated also in the footer of pages and in the parent categories
-->

|-
| '''Headers'''
| Headers can in principle be tied to the following paragraph, but it is better to have them separated. This way someone can quickly translate the table of contents before going into the contents. When tagging headers, it is important to include the header markup inside the tags, or MediaWiki will no longer identify them properly, for example when trying to edit a specific section of the source page. The markup also immediately gives translator a context: he/she is translating a header.
|
'''Wrong:'''
<pre>== &lt;translate>Culture&lt;/translate> ==</pre>

'''Correct:'''
<pre>&lt;translate>== Culture ==&lt;/translate></pre>
'''Suggested segmentation:'''
<pre>
&lt;translate>
== Culture ==

Lorem ipsum dolor.
&lt;/translate>
</pre>

|-
| '''Images'''
| Images that do contain language specific content like text should include the full image syntax in an unit. Other images can only tag the description with optional hint in message documentation of the page after it has been marked.
|
<pre>
&lt;translate>
[[File:Europe.png|thumb|right|Map of Europe with capital cities]]
&lt;/translate>
</pre>
<pre>
[[File:Ball.png|50px|&lt;translate>Ball icon&lt;/translate>]]
</pre>

|-
|'''Links'''
| Links can be included in the paragraph they are inside. This allows changing the link label, but also changing the link target to a localized version if one exists.

Because headers are translated, you cannot rely on the automatically generated id's for headers. You can add your own anchors. To have them outside of the translation template you need to break up the page into multiple translate tag pairs around each header you want to have an anchor to.
|
'''Internal links:'''
<pre>&lt;translate>
Helsinki is capital of [[Finland (country)|Finland]].
&lt;/translate></pre>
'''External links:'''
<pre>&lt;translate>
PHP ([http://php.net website]) is a programming language.
&lt;/translate></pre>
'''Links within a page:'''
<pre>
<span id=culture></span>
&lt;translate>
== Culture ==

Lorem ipsum dolor.

...

For more about food, see [[#culture|section about culture]].
&lt;/translate></pre>

|-
| '''Lists'''
| Lists can get long, so might want to split them into multiple parts with for example five items or less in each as follows. Do so only if the items are sufficiently independent to be translate separately in all languages, don't create "lego messages": for instance, you must avoid to split a single sentence in multiple units, or to separate logically dependent parts which may affect each other (with regard to punctuation or style of the list, for instance). To split a list, use <code>&lt;translate></code>-tags. Do not insert new lines as this will break the HTML output.
|
<pre>
&lt;translate>
* General principles
* Headings
* Images
* Tables
* Categories
&lt;/translate>
&lt;translate>
* Links
* Templates
&lt;/translate>
</pre>

|-
| '''Numbers'''
| With numbers and other non-linguistic elements you may want to pull the actual number out of translation and make it a variable. This has multiple benefits:

* You can update the number without invalidating translations.
* Translation memory can work better when the changing number is ignored.
|
<pre>&lt;translate>
Income this month &lt;tvar|income>{{FORMATNUM:3567800}}</> EUR
&lt;translate></pre>
Note that this prevents the translators from localising the number by doing currency conversion. The <code>FORMATNUM</code> call makes sure the number is formatted correctly in the target language.

|-
| '''Templates'''
| Templates have varying functions and purposes, so the best solution depends on what the template is for. If the template is not a part of longer paragraph, it should be left out, unless it has parameters that need to be translated. If the template has no linguistic content itself, you don't need to do anything for the template itself.
| For an example of templates translated with page translation, see [[Template:Extension-Translate]]. To use this template, you need to have another template similar to [[Template:Translatable navigation template]], because you cannot include the template by <nowiki>{{TemplateName}}</nowiki> anymore. This is not ''yet'' provided by the Translate extension itself, but that is in the plans.

Another way is to use the [[Special:MyLanguage/Help:Extension:Translate/Unstructured element translation|unstructured element translation]] to translate the template, but then the language of the template will follow the user's interface language, not the language of the page he is viewing.
|}

<span id=changes></span>

== Changing the source text ==

General principles:

* Avoid changes
* Make the changes as isolated as possible
* Do not add translation unit markers yourself

'''Unit markers.''' When page is marked for translation, the system will update the translatable page source and add unique identifiers for each translation unit. See example below.
These markers are crucial for the system, which uses them to track changes to each translation unit. You should never add unit markers yourself. The markers are always on the line before the unit; or, if it starts with a header, after the first header on the same line. The different placement for headers is needed to keep section editing working as expected.

<pre>
&lt;translate>
== Birds == &lt;!--T:1-->
Birds are animals which....

&lt;!--T:2-->
Birds can fly and...
&lt;/translate>
</pre>
'''Changing unit text.''' Changing is the most common operation for translation units. You can fix spelling mistakes, correct grammar or do other changes to the unit. When re-marking the page for translation, you will see the difference in the unit text. The same difference is also shown to translators when they update their translations. For simple spelling fixes and other cases where you don't want the existing translations to be removed from translation pages, you can avoid invalidating them: translators will still see the difference if they ever update the translation for any reason.

'''Adding new text.''' You can freely add new text inside translate tags. Make sure that there is one empty line between adjacent units, so that the system will see it as a new unit. You can also add translate tags around the new text, if it is not inside existing translate tags. Again, do not add unit markers yourself, the system will do it.

'''Deleting text.''' You can delete whole units. If you do so, also remove the unit marker.

'''Splitting units.''' You can split existing units by adding an empty line in the middle of a unit, or by placing translate tags so that they split the unit. You can either keep the unit marker with the first unit or remove it altogether. In the first case, translators see the old text when updating the old translation. If you removed the unit marker, both units will behave as if no translation ever existed, after the page is re-marked for translation.

{| class=wikitable
! Original state !! Keeping the marker !! Removing the marker
|- style="vertical-align:top"

|
 &lt;!--T:1-->
 Cat purrs. Dog barks.
|
 &lt;!--T:1-->
 Cat purrs.
 
 &lt;!--T:2--> ''(Added after remarking)''
 Dog barks.
|
 &lt;!--T:2--> ''(Added after remarking)''
 Cat purrs.
 
 &lt;!--T:3--> ''(Added after remarking)''
 Dog barks.
</pre>

|- style="vertical-align:top"

| Kissa kehrää. Koira haukkuu.
| Kissa kehrää. Koira haukkuu.

Dog barks.
| Cat purrs.

Dog barks.
|}
'''Merging units.''' If you merge units, you have to remove at least all but one unit marker.

'''Moving units.''' You can move units around without invalidating translations: just move the unit marker together with the rest of the unit.

Before marking the new version of the page for translation, ensure that the best practices are followed, especially that translators get a new translation unit if the content has changed. Also make sure that there are no unnecessary changes to prevent wasting translators time. If the source page is getting many changes, it may be worthwhile to wait for it to stabilize, and push the work for translators only after that.

Unused unit translations are not deleted automatically, but that should not cause trouble.

<span id=migration></span>
== Migrating to page translation ==

If you have been translating pages before using the page translation system, you might want to migrate the pages to the new system, at least the ones you expect to have new translations and want statistics for. You will probably have existing templates for language switching and maybe different page naming conventions.

You can start migration by cleaning up, tagging and marking the source page. You can keep the existing language-switching templates while you migrate the old translations. If your pages follow the language code subpages naming convention, they will be replaced with the source text after marking the source page for translation, but you'll still be able to access translations from history.

This is manual work, where you have to open the old translation page and copy and paste translations from there to correct translation units in the new system using the translation interface. For this you need to roughly know which part of the translation matches which part of the old text (and hope they match). You might want to consider marking all the migrated translations as needing update by prepending the string !!FUZZY!! to the translations and have a translator look at them. Once migrated, you can delete the old translation pages if they are not using the same naming convention (or you could have switched them to it before migration). Once all pages are migrated you can also remove old language navigation templates.