[Django] #32737: get_language_info replaces requested language code with the one found in django.conf.locale.LANG

Django

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May 10, 2021, 2:17:17 PM5/10/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody
Type: Bug | Status: new
Component: | Version: 3.1
Internationalization | Keywords: i18n,
Severity: Normal | get_language_info, language code,
Triage Stage: | LANG_INFO, documentation
Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
== Issue

while following the instructions at
[https://docs.djangoproject.com/en/3.1/topics/i18n/translation/#the-set-
language-redirect-view The set_language redirect view] i tried the
following:
{{{
# settings.py
LANGUAGE_CODE = 'de-ch'
LANGUAGES = [('de-ch', _('Swiss German')),
('fr-ch', _('Swiss French')),
('en', _('English'))]

# some_template.html
<form id="set_lang" action="{% url 'set_language' %}"
method="post">
{% csrf_token %}
<input name="next" type="hidden" />
<li class="nav-item input-group">
<select name="language" class="custom-select"
id="lang_selection">
{% get_current_language as LANGUAGE_CODE %}
{% get_available_languages as LANGUAGES %}
{% get_language_info_list for LANGUAGES as languages %}
{% for lang in languages %}
<option value="{{ lang.code }}"
{% if lang.code == LANGUAGE_CODE %}
selected{% endif%}>
{{ lang.name_local }} ({{lang.code}})</option>
{% endfor %}
</select>
<div class="input-group-append">
<button class="btn btn-outline-secondary" type="submit"
id="set_lang_btn">
{% translate "Select language" %}</button>
</div>
</li>
</form>
}}}

my widget failed to recognize the currently selected language. not sure if
i missed something or the documentation doesn't (yet) cover this
particular use-case.

== Context
the variables set in the template code above are set as follows:
{{{
LANGUAGE_CODE = 'fr-ch'

LANGUAGES = [('de-ch', 'allemand suisse'), ('fr-ch', 'fran&ccirc;ais'),
('en', 'anglais')]

languages = [{'bidi': False, 'code': 'de', 'name': 'German', 'name_local':
'Deutsch', 'name_translated': 'Allemand'}, {'bidi': False, 'code': 'fr',
'name': 'French', 'name_local': 'français', 'name_translated':
'Français'}, {'bidi': False, 'code': 'en', 'name': 'English',
'name_local': 'English', 'name_translated': 'anglais'}]
}}}
switching languages and i18n in general work just fine.

== Analysis
testing against 'fr-ch' fails because after applying
get_language_info_list() to the list of available languages (LANGUAGES)
lang.code is the code from the base language found in
django.conf.locale.LANG_INFO ('fr' in this case) and not necessarily the
code being requested ('fr-ch').

not sure if i'm missing something from the documentation, or if this is
intended behavior.

imho getting the information for the base language is fine, but having the
option of (easily) checking the currently selected language is necessary.

== Test
{{{
from django.utils.translation import get_language_info

lang_code = 'fr-ch'
info = get_language_info(lang_code)
assert lang_code == info['code']
}}}

== Possible Solutions
=== a) replace the code in the retrieved data to match the requested code
i wasn't able to test this but i guess one could simply add the requested
code to the returned LANG_INFO[lang_code] object, i.e. by adding the line:
{{{
info['code'] = lang_code[0]
}}}
towards the end of django.utils.translation.get_language_info. not sure if
this is desired behavior though
=== b) add documentation on how this particular use-case should be handled

--
Ticket URL: <https://code.djangoproject.com/ticket/32737>
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Django

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May 11, 2021, 2:49:39 AM5/11/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Claude Paroz):

* status: new => closed
* resolution: => invalid

Comment:

I think this is expected behaviour, because Django has no `fr-ch`
translations (French translators do not think it's worth maintaining
country-specific translations).

If you really want it, you could add any "new" language by following
https://docs.djangoproject.com/en/stable/topics/i18n/translation
/#localization-how-to-create-language-files

I'm closing the ticket, but this does not mean we cannot continue the
discussion, if needed.

--
Ticket URL: <https://code.djangoproject.com/ticket/32737#comment:1>

Django

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May 11, 2021, 4:14:44 AM5/11/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by ruffni):

aha! i see what i missed to say before:

Replying to [comment:1 Claude Paroz]:

> If you really want it, you could add any "new" language by following
https://docs.djangoproject.com/en/stable/topics/i18n/translation
/#localization-how-to-create-language-files

this is exactly what i did!

i added the locale directory, made the messages (for language codes 'de-
ch' and 'fr-ch' respectively), compiled them (it all works great). but
still: comparing LANGUAGE_CODE to get_language_info('de-ch') **always
fails**, see above.
nota bene: i'm not talking about some generic translations or anything
alike, i'm talking about translations for languages we provide explicitly

> I'm closing the ticket, but this does not mean we cannot continue the
discussion, if needed.

i have some doubt about this being intended behavior.

--
Ticket URL: <https://code.djangoproject.com/ticket/32737#comment:2>

Django

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May 11, 2021, 4:26:48 AM5/11/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Claude Paroz):

Would be great to have a sample project to reproduce the issue.

--
Ticket URL: <https://code.djangoproject.com/ticket/32737#comment:3>

Django

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May 11, 2021, 5:16:18 AM5/11/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by ruffni):

* Attachment "translations.zip" added.

example project

Django

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May 11, 2021, 5:22:25 AM5/11/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by ruffni):

Replying to [comment:3 Claude Paroz]:

> Would be great to have a sample project to reproduce the issue.

added the sample project. it's the same issue with django 3.2 (not sure
whether to change the version description of this ticket or not)

--
Ticket URL: <https://code.djangoproject.com/ticket/32737#comment:4>

Django

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May 11, 2021, 6:10:01 AM5/11/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Claude Paroz):

* status: closed => new
* type: Bug => Cleanup/optimization
* version: 3.1 => dev
* resolution: invalid =>
* stage: Unreviewed => Accepted

Comment:

Thanks a lot for the sample project. I'm reopening at least for the
missing documentation which should tell that `get_language_info` and
`get_language_info_list` only return information for languages included in
Django.

In your specific use case, I would simply rewrite your language selector
as:
{{{

<select name="language" class="custom-select" id="lang_selection">
{% get_current_language as LANGUAGE_CODE %}
{% get_available_languages as LANGUAGES %}

{% for code,lang_name in LANGUAGES %}
<option value="{{ code }}" {% if code == LANGUAGE_CODE %}
selected{% endif%}>
{{ lang_name }} ({{code}})</option>
{% endfor %}
</select>
}}}

If we wanted custom languages data entering Django's `LANG_INFO`, it would
require some deeper refactoring with language data embedded somewhere
inside the locale folders (maybe in `__init__.py`?). Don't know if it's
really worth the effort…

--
Ticket URL: <https://code.djangoproject.com/ticket/32737#comment:5>

Django

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May 12, 2021, 9:08:46 AM5/12/21

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#32737: get_language_info replaces requested language code with the one found in
django.conf.locale.LANG_INFO
-------------------------------------+-------------------------------------
Reporter: ruffni | Owner: nobody

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by ruffni):

Replying to [comment:5 Claude Paroz]:

> Thanks a lot for the sample project. I'm reopening at least for the
missing documentation which should tell that `get_language_info` and
`get_language_info_list` only return information for languages included in
Django.

yeah, still not completely sure whether this can be sold as intended
behavior (to replace a given language code from settings with the code for
the language present in the django admin). "languages included in Django"
is what irritates imho. this implies languages defined in settings.py are
not included?

> In your specific use case, I would simply rewrite your language selector
as:
> {{{

> <select name="language" class="custom-select" id="lang_selection">
> {% get_current_language as LANGUAGE_CODE %}
> {% get_available_languages as LANGUAGES %}

> {% for code,lang_name in LANGUAGES %}

> <option value="{{ code }}" {% if code == LANGUAGE_CODE %}
selected{% endif%}>
> {{ lang_name }} ({{code}})</option>
> {% endfor %}
> </select>
> }}}
thanks for the snippet!
now though, the language selection gets displayed in the currently active
language (which is fine in my case where there's only 3 languages).
assuming there were a website with dozens of languages with different
alphabets and reading directions and whatnot, this would definitely be a
deal breaker for usability. imagine trying to find the arabic string for
the word "english" in a drop-down menu full of arabic strings -> mission
impossible.

> If we wanted custom languages data entering Django's `LANG_INFO`, it
would require some deeper refactoring with language data embedded
somewhere inside the locale folders (maybe in `__init__.py`?). Don't know
if it's really worth the effort…

i guess some re-working will have to be done to resolve the issue in a
nice way.

either defining country-specific translations to be second-class citizens
(which django may or may not fall back to if there is no translation for
the standard-language; i.e. selecting translations from 'fr-ch' if French
is requested but code 'fr' is not found) or completely differentiating
between pre-existing languages (the ones you called "included" above) and
ignoring them as soon as LANGUAGES is defined in settings.py.

--
Ticket URL: <https://code.djangoproject.com/ticket/32737#comment:6>

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