Calling `reverse` in `templatetags` reverts admin site to default

[dickermoshe]

What version of Unfold are you using?

v0.50.0

What version of Django are you using?

Chrome 133.0.6943.142 (Official Build) (64-bit)

What browser are you using?

For example: Firefox 128.0

Did you checked changelog/commit history, if the bug is not already fixed?

Yes

Did you searched other issues, if the bug is not already fixed?

Yes

Did you checked documentation?

Yes

Are you able to replicate the bug in the demo site?

Yes

Repository with reproduced bug

https://github.com/dickermoshe/repro_unfold

Describe your issue

I'm using reactpy_django and it's seems that it replaces the unfold site with the default site when it's setup.
The result is an empty admin site that has no models registered.

The sequence of events are as follows:

1. Unfold replaces admin site
2. Models are registered on the Unfold site
3. calling reverse in templatetags reverts back the original site
4. This is becuase reverse calls resolver.app_dict which forces the resolver to _populate(). This completly recomputes the entire urlresolver

I traced the issue to using reverse function in templatetags. The repo above contains a self contained reproduction of this issue without reactpy_django.

[dickermoshe]

Workaround:
Call get_resolver(get_urlconf()).app_dict at the bottom of your urls.py file

[lukasvinclav]

Maybe you are looking for this https://unfoldadmin.com/docs/sites/ chapter "Overriding the default admin site"

[dickermoshe]

@lukasvinclav Please don't close this. This is issue is not resolved at all.
This does not relate to overring the default admin site at all.

[lukasvinclav]

@dickermoshe okay, so I reopened the issue. Would you mind to describe the issue again?

[dickermoshe]

Sure.

Calling reverse in a custom templatetag breaks the entire django app.
The repo I've linked in the issue contains the smallest possible reproducible project.
https://github.com/dickermoshe/repro_unfold

more specifically, this file:
This is a default Django project, with an default app added which also contains this file :https://github.com/dickermoshe/repro_unfold/blob/master/some_app/templatetags/__init__.py

[lukasvinclav]

I don't see any template tag in your repo. Where it is? The code in __init__.py is not a templatetag. What is the error which you get? Can you post the stack trace?

[dickermoshe]

It does not have to be in a template tag itself.

When django starts up it looks in the templatetag module to discover custom tags.
If reverse is called at that time, the admin site wont load.

Internal Server Error: /admin/
Traceback (most recent call last):
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\core\handlers\exception.py", line 55, in inner
    response = get_response(request)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\core\handlers\base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\contrib\admin\sites.py", line 260, in wrapper
    return self.admin_view(view, cacheable)(*args, **kwargs)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\utils\decorators.py", line 188, in _view_wrapper
    result = _process_exception(request, e)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\utils\decorators.py", line 186, in _view_wrapper
    response = view_func(request, *args, **kwargs)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\views\decorators\cache.py", line 80, in _view_wrapper
    response = view_func(request, *args, **kwargs)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\contrib\admin\sites.py", line 241, in inner
    return view(request, *args, **kwargs)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\unfold\sites.py", line 118, in index
    app_list = self.get_app_list(request)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\contrib\admin\sites.py", line 541, in get_app_list
    app_dict = self._build_app_dict(request, app_label)
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\contrib\admin\sites.py", line 525, in _build_app_dict
    "app_url": reverse(
               ~~~~~~~^
        "admin:app_list",
        ^^^^^^^^^^^^^^^^^
        kwargs={"app_label": app_label},
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        current_app=self.name,
        ^^^^^^^^^^^^^^^^^^^^^^
    ),
    ^
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\urls\base.py", line 88, in reverse
    return resolver._reverse_with_prefix(view, prefix, *args, **kwargs)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\dicke\DickerSystems\repro_unfold\.venv\Lib\site-packages\django\urls\resolvers.py", line 831, in _reverse_with_prefix
    raise NoReverseMatch(msg)
django.urls.exceptions.NoReverseMatch: Reverse for 'app_list' not found. 'app_list' is not a valid view function or pattern name.
[30/Mar/2025 11:28:45] "GET /admin/ HTTP/1.1" 500 116599

You can reproduce this by cloning the repo

git clone https://github.com/dickermoshe/repro_unfold
cd repro_text
uv sync
uv run python manage.py migrate
uv run .\manage.py createsuperuser --username a --email a@a.com
# Enter Password
uv run python manage.py runserver
# Visit admin site and login

[lukasvinclav]

Do you have this error when not using Unfold?

[dickermoshe]

No. It only happens when using unfold.

[lukasvinclav]

@dickermoshe is it okay to call a reverse in __init__? From my perspective, this is a bug. If you want to use reverse, use it directly in templatetag.`

[dickermoshe]

Sorry for not gettig back to you eirlier.

This bug makes using unfold with reactpy not possible. I don't actually control the code which makes the reverse call in my project.

This is the offending code:

https://github.com/reactive-python/reactpy-django/blob/feacabc76cf1eb20d5dfccf1568c70b2be05b85c/src/reactpy_django/templatetags/reactpy.py#L37-L41