Odtnhj

I am using Django (version 2.1.3) in one of my project and currently struggle with a weird bug. I use the build in internationalization module and included a language toggler in my main menu which is loaded on every page

% get_current_language as LANGUAGE_CODE %
<form id="form" action="% url 'set_language' %" method="post">
 % csrf_token %
 <input name="next" type="hidden" value="strip_lang " />
 <input id="form_lang" name="language" type="hidden" value=" LANGUAGE_CODE "/>
</form>
<ul role="menu" class="dropdown-menu"id="lang-dropdown">
% get_available_languages as LANGUAGES %
% get_language_info_list for LANGUAGES as languages %
% for language in languages %
 <li>
 <a href="#" onClick='(function() 
 document.getElementById("form_lang").value = " language.code "; 
 document.getElementById("form").submit(); return false;)();return false;'>
 language.name_local ( language.code )</a>
 </li>
% endfor %
</ul>

I created a special tag "strip_lang" to strip the language identifier from the current URL.

@register.filter
@stringfilter
def strip_lang(value):
 """Removes all values of arg from the given string"""
 lang = getattr(settings, "LANGUAGES", None)
 url = value.split('/')
 if url[1] in [l[0] for l in lang]:
 return urllib.parse.unquote('/' + '/'.join(value.split('/')[2:]))
 else:
 return urllib.parse.unquote(value)

This all works well. However, for one of my apps, I always get rerouted to a different app.
ie if I am at path

 /en/app1/mypage1 

and toggle the language i suddenly end up at

 /fr/app2/mypage1

*****EDIT*****

Referals for app2 work correctly. When entering a URL manually for app1 the pages load correctly.

My url.py in the main project looks like this

urlpatterns = [
 path('admin/', admin.site.urls),
 path('i18n/', include('django.conf.urls.i18n')),
 ]
urlpatterns += i18n_patterns(
 path('app1/', include('app1.urls')),
 path('app2/', include('app2.urls')),
 path('app3/', include('app3.urls')),
 url(r'^$', TemplateView.as_view(template_name='home.html'), name='home'),
 url(r'^login/$', auth_views.LoginView.as_view(), 'template_name': 'login.html', name='login'),
 url(r'^logout/$', auth_views.LogoutView.as_view(), 'template_name': 'logged_out.html', name='logout'),
 url(r'^oauth/', include('social_django.urls', namespace='social')),
prefix_default_language=False)

ans urls.py of my apps look like this

urlpatterns = [
 path('', views.index, name='index'),
 path('surveys/', views.nrgt_surveys, name='nrgt_surveys'),
 path('surveys/<str:survey_name>/', views.survey, name='survey'),
 path('surveys/<str:survey_name>/<query_name>', views.survey_query, name='survey_query'),
 path('landscapes/', views.landscapes, name='landscapes'),
 path('landscapes/<str:landscape_name>/', views.landscape, name='landscape'),
 path('landscapes/<str:landscape_name>/<query_name>', views.landscape_query, name='landscape_query'),
]

I do not specify the app name anywhere in my code. When I track my network requests I can also see that the correct URL is submitted in the POST request. Why does my url get modified?