Multilingual wiki - Page translations (forum / topic / answer) causes many issues with the current Forum

[ane-gabriela]

Steps to reproduce:

1. Log in as Admin
2. Make the wiki multilingual (eg. Multilingual > Yes, Supported Languages EN, FR, DE, IT)
3. Create a new Forum, Topic, Answer
4. Translate the Forum, Topic and Answer in all the other languages using WYSIWYG or Wiki mode
5. Observe the effects of the translations

Expected results: The pages are properly translated and shown.

Actual results:

• The forum list in the Forum home LiveTable is properly shown as per the language selected eg. in this case French (xwiki/bin/view/Forums/) but once clicked (xwiki/bin/view/Forums/English%20Forum/) the DEFAULT title and text appear which in this case is English instead of French. Editing in Inline mode makes the Default language appear, editing in WYSIWYG or Wiki mode makes the French one appear.
• The Topic appears 4 times in the list (xwiki/bin/view/Forums/English%20Forum/) as per the number of translations but it appears with the Title and Description text of the default language no matter the wiki language selected eg. in this case the wiki was in German and the topics appear in French.
• If a vote or Answer is given it appears in all the multiplicated topics
• Once the topic is clicked the proper Title appears (according to the selected wiki language) but the text in Description remains the one from the default language
• The multiplicated topics appear in the "Most Active Topics" panel too but with the name of the default language no matter the wiki language
• The Answers appear only as the text added in Inline mode no matter the language selected
• Once a comment is added to the Answer, the Answer and Comment appears 4 times too
• The Comments can't be translated and appear the same for all wiki languages - the possibility to have comments language depended should be added also

Environment: Windows 10, XWiki 10.11.1 with MySQL 5.7 and Edge 18

[polx]

I gae it a bit of twist and can say that, simply said, the Forum App is not made for internationalization. Here are a few reasons:

• while you can create a ForumTopic in different languages if you use the page-translation-feature, they will not be stored: Topics and comments are stored in objects which have an independent life of translations (in particular, they are not attached with a language). You can see that by creating a wiki page and edit with editor=object, add a random object, then change language: the object is still there. For them to work multilingual they should either be contained in the pages content or carry a language property.
• the list of posts is indeed multiplied by the number of pages that are done, but they repeat a single version (that is stored in the object)
• the translation feature was not immediately present to me (even the "translate to language x" was to be added by hand as a panel) and it is reset by the Forum Application's feature which redefines panel at each space (including topics and forums). This might have been a delicacy of my installation (possibly, I have made the installation in the wrong order). If my method of installation is normal then it is really improbable that the forum becomes used multilingual as this test-case aims at.

For the Forum to become multilingual, one needs a complete design:

• decide where to store the different translations
• decide what to do in case of lack of translation (language precedence (currently of a single level in XWiki, assumption that a main language always exists, happily mix languages or rather hide missing translations)
• decide workflows when, say, a user with a German UI answers a post in Rumanian (should the language be asked? should it be German?). In some cases, in would be contemporary to recognize automatically the language with some detectors (e.g. this one).

[polx]

I am trying to find a way to avoid the annoyance you met. Maybe the solution is that the selection of the list of pages to display be grouped-by by language.

It should be in principle possible to just have each forum be language specific because the entry page is in a different language. One should just avoid to aim at multilinguality of a forum before we can do it. Possibly we should warn about it and prevent it, in case we come into the edit of a topic. I believe that this is not too complex but definitely makes forums non-multilingual.