Chinese is missing from the language selector despite existing translation files

[TheStarsBlink]

Current behavior

In my GeoNode deployment (current checkout reports 5.1.0 dev), the language selector does not offer Chinese, so I cannot switch the interface to Chinese through the menu.

However, my checkout includes Chinese translation files:

geonode/locale/zh/LC_MESSAGES/django.po
geonode/locale/zh/LC_MESSAGES/django.mo
geonode/locale/zh/LC_MESSAGES/djangojs.po
geonode/locale/zh/LC_MESSAGES/djangojs.mo

I also noticed that the default language definitions in geonode/settings.py include zh-cn, while the translation directory is named zh. I do not know whether this difference is related to the missing menu option.

Steps to reproduce in my deployment

1. Open the GeoNode catalogue interface.
2. Open the language selector.
3. Look for Chinese / 中文: the option is not available.

Expected behavior

Chinese should be selectable when it is enabled and the required translations are available, or the documentation should explain any additional configuration needed to expose it in the language selector.

Questions

• Is Chinese intentionally unavailable in the language selector by default, despite the existing translation files?
• Which configuration controls the languages shown in the catalogue language selector? Are separate GeoNode/Django and MapStore frontend settings or translation bundles required?
• What is the recommended way to enable Chinese consistently, and which language code should be used (zh, zh-cn, or another code)?

I would appreciate guidance on whether this is a deployment configuration issue, a frontend translation limitation, or a bug.

[TheStarsBlink]

Adding just the ("zh-cn", "Chinese") entry to MAPSTORE_DEFAULT_LANGUAGES makes Chinese available in the language selector:

MAPSTORE_DEFAULT_LANGUAGES = (
    ("de-de", "Deutsch"),
    ("en-us", "English"),
    ("es-es", "Español"),
    ("fr-fr", "Français"),
    ("it-it", "Italiano"),
    ("zh-cn", "Chinese"),
)

Since this only requires adding one entry, why isn't Chinese included in the project's default configuration? Is there a specific reason for leaving it out?

[giohappy]

The reason is that nobody asked for it before @TheStarsBlink :)
Really, there isn't a strong reason for the selection of the pre-configured languages, other than their completeness and maintenance.

The translations in GeoNode are composed of:

• Django .po/.mo files: legacy UI (still in use for some pages) and REST APIs. For Chinese, you can find them here
• MapStore translation JSON files for most of the GeoNode frontend application (GeoNode client), which is built on top of MapStore. data.zh-ZH.json exists for Chinese but it's not complete,
• GeoNode client-specific translations. Here, Chinese and many others are missing...

If we enable the Chinese language now, most of the frontend app would be in English, with only some buttons and text translated.

The mechanism behind the language settings is:

• you enable the language (you can do it with the settings in your GeoNode Project, or with an environmental variable)
• If the language key is "zh-zh" Django will fall back to the "zh" translation files (since there are no "zh-zh" message files)
• MapStore will look for the "zh-ZH" JSON file when the client application loads

"zh-cn" works the same for the Django part, since "cn" is stripped and it does a fallback on "zh" files, but the client won't find any "zh-CN" JSON file.

I take this opportunity to invite you to contribute to the translation. It would be a very welcome contribution.