Looks good, mostly things are working, but I have a few suggestions for changes:

1. The "All languages" option should be last, after the languages, not first, just like in Skosmos 2.
2. The "All languages" option could be called "Any language" in English, just like in Skosmos 2.
3. I suggest renaming the variables $searchLangList and $vocabSearchLangList (php), search_lang_list (twig) and searchLangStrings (SKOSMOS object). These are indeed used for the search language dropdown (along with the "all"/"any" option), but I think it would be better to call these "content languages" so they align with e.g. the content_lang and clang variable names. For example searchLangStrings could be called contentLanguages.
4. The SKOSMOS object now has both languageOrder and searchLangStrings fields, for slightly different reasons, but both containing a list of languages. Would it be possible to get rid of languageOrder and instead order searchLangStrings/contentLanguages in the right order?
5. This isn't a new bug in this PR (found by @UnniKohonen ), but I think it needs to be fixed: in the vocabulary search bar, selecting the "All languages" (or "Any language") option causes SKOSMOS.content_lang to be set to "all", which breaks the sidebar components that expect a language tag and not this special value:

   Skosmos/resource/js/vocab-search.js

   Line 198 in 072d67f

   window.SKOSMOS.content_lang = clang

Avoiding passing languageOrder separately is much better now. However, I have some doubts about parseVocabularyLanguageOrder:

• getLanguageOrder should be given the current content language, not null
• $languageOrder can never be null so the if is_null check is useless (in my understanding)
• no need to assign to a variable in the end, could just return the expression directly

I think we need a PHPUnit test (or several) for this method, because it does non-trivial things and I suspect that it could be buggy and/or contain dead code.

Other comments:

I noticed that $langList (php) and lang_list (twig) variables are still declared within WebController::invokeGlobalSearch even though they are not used in Twig templates. They should be deleted.

I have some suggestions for renaming variables / methods to make them clearer:

• allLanguages method -> anyLanguage
• allLanguegesEntry -> anyLanguageEntry (note the typo in the current name)
• $contentLangList -> $contentLanguages
• content_lang_list -> content_languages
• $sortedContentLangList -> $contentLanguages or $sortedContentLanguages

As a final nitpick, the formattedList variable in both the formatLangStrings methods is useless and the value could just be returned directly.

There's a problem with the new PHPUnit test. I suggested how to fix it in a comment.

Otherwise looks good, though I dislike the variable/method names *LangStrings (within the SKOSMOS object and in Vue code); I don't think the value being a string is a relevant aspect and I would rather rename them to *Languages, like this:

• formatLangStrings -> formatLanguages
• langStrings -> languages
• contentLangStrings ->contentLanguages

But I've already nitpicked a lot about variable names a lot in the previous round so I leave this up to you to decide. 😉

After considering these, this PR can be merged. It's a big improvement for the search bars!