UI: Add a whitelist in i18next to fix the issue #675

[ericsyh]

Why for change

To fix #675.
The root cause of issue is we declare two languages as zh-CN and en in i18next while some situations browser will return zh (Under my case the browser is Chrome 83 the OS is Windows 10) which is out of our language definition.

What did i do

I added a whitelist only for zh-CN and en in i18next to block other cases. With the whitelist i18next will fallback to en by default if browser return language out of our definition like zh or en-US.

Test

Passed on my environment. Now i18next got en as i18nextLng

[ericsyh]

@baurine PTAL :)

[baurine]

So by this way, 'zh-HK' / 'zh-TW' / 'zh-SG' (https://www.andiamo.co.uk/resources/iso-language-codes/) will be fallback to 'en' as well (need extra tests to confirm), not sure whether i18next has a customized fallback strategy.

[ericsyh]

Seems no customized fallback provided in i18next but has custom Detector. I tried it but do not figure it out :(

[baurine]

According to the document: https://www.i18next.com/principles/fallback

1. Per default locals containing region or script will take a translation from the pure language file if not found. (https://www.i18next.com/principles/fallback#locals-resolving). It means 'zh-XX' will fallback to 'zh' automatically

2. We can define an object for fallbackLng (https://www.i18next.com/principles/fallback#fallback-language) like this:

   fallbackLng: { 
       'zh-HK': ['zh-CN', 'en'], 
       'zh-TW': ['zh-CN', 'en'],
       ...
   }
   

I prefer to use the way 1. We can change all places used by 'zh-CN' to 'zh'. (for example, zh-CN.yaml to zh.yaml), this can prevent 'zh' / 'zh-HK' / 'zh-TW' / 'zh-SG' / 'zh-XXX' except 'zh-CN' fallback to 'en' with no more configuration. (need test to confirm)

@breeswish , how do you think about it?

[baurine]

Or I can try the custom detector later.

[breezewish]

Yes, I also think solution 1 looks best

#677 (comment)

[baurine]

Thanks for your contribution! LGTM, I will have a test soon.

[baurine]

Works fine as expected.

[ti-srebot]

@baurine,Thanks for your review.

[baurine]

/merge

[ti-srebot]

Sorry @baurine, you don't have permission to trigger auto merge event on this branch. The number of LGTM for this PR is 1 while it needs 2 at least

[breezewish]

We no longer have this file, you can remove it

[ericsyh]

I see, you moved dashboard setting to the user profile page in previous commit. I will remove it.

[ericsyh]

Push a new commit 436817d to remove the dashboard setting page.

[breezewish]

The rest LGTM, thanks!

[breezewish]

/merge

[ti-srebot]

/run-all-tests

[breezewish]

@all-contributors please add @ericsyh for code

[allcontributors]

@breeswish

I've put up a pull request to add @ericsyh! 🎉