Allow separate access to matches from urlpatterns and extra_context args

[Florian Apolloner]

Currently Django's ResolverMatch (eg the one returned by urlresolvers.resolve) gives access to args and kwargs which are ready to be passed to the func being resolved. This does eliminate the possibility of an interesting use-case:

Let's assume I have a page written in english and german. I configured my urls using the new urlpatterns like this:

urlpatterns = i18n_patterns('',
    url(_(r'^about/$'), 'about.view', {'some_extra': 'data'}, name='about'),
    url(_(r'^news/$'), 'home.view', {'some_extra': 'data'}, name='home'),
)

I now would like to give my visitors an easy way to access the content in german. So my /about should have a link to /über. To do that, one could write a templatetag which does the following:

match = urlresolvers.resolve('current-url')
links = []
for lang in settings.LANGUAGES:
  translation.activate(lang):
  links.append(reverse(match.url_name, args=match.args, kwargs=match.kwargs))
# Further logic to display the links in the template

This doesn't work since the ResolverMatch combined the kwargs captured from the url-regex with the dictionary supplied for the extra data.

I think it would be a great if the ResolverMatch would give access to kwargs and extra_context separately. There might be more usecases, but that's the only one I can come up with for now. From a quick view at the code it should be possible to do that backwards-compat (eg ResolverMatch.__getitem__ would still return the current result but internally it would use two dictionaries).

[Florian Apolloner]

simple patch demonstrating the feature

[Jacob]

Good idea!

[Florian Apolloner]

New and cleaner patch, but it does change behavior (see changes of the doc file)

[antoviaque]

Looks like you beat me to the update apollo : )

I've added a test specific to the behavior change though, you may want to integrate it in your patch.

[anonymous]

If your patch includes my changes that should be fine…

[Tim Graham]

Patch no longer applies cleanly.

[Alexandre Prieto Pantoja]

Hello,

I'am trying to figure out the context of this ticket but I am rather stuck on the resolution until now.

I reproduced the use case with the information in the ticket. My code is now the following:

views.py file:

from django.shortcuts import render
from django.urls import resolve, reverse
from django.utils import translation
from django.utils.translation import gettext as _

def homepage(request, *args, **kwargs):
    links = []
    langs = settings.LANGUAGES
    match = resolve(request.path) 
    
    for lang in langs:         
        with translation.override(lang[0]):                  
            links.append(reverse(match.url_name, args=match.args, kwargs=match.kwargs))
     
    message = _('Welcome to our site!')
   
    return render(request, 'ticket_16406/homepage.html', {'message': message, 'links':links})

url.py file:

from django.conf.urls.i18n import i18n_patterns
from django.contrib import admin
from django.urls import path, re_path
from django.utils.translation import gettext_lazy as _
from ticket_16406 import views


urlpatterns = [
    path(_('admin/'), admin.site.urls),
]
urlpatterns += i18n_patterns(    
    re_path(_(r'^home/(?P<slug>[\w-]+)/$'), views.homepage, {'extra': True}, name="homepage"),
)

template

    {% for link in links %}
        <a href={{ link }}>{{ link }}</a>
    {% endfor %}

I have access to content in different languages in my template.

I don't find the problem I have to tackle here.

Could you give me  more information/details on  "why the patch no longer applies cleanly"?

It would be a great help. Thanks!

[Pedro Schlickmann Mendes]

Replying to David Smith:
Can you give us more details on why the patch no longer applies cleanly?

[Alokik Roy]

PR of my work so far:
​https://github.com/django/django/pull/15402

[Tim Graham]

The patch is missing tests (all code changes require tests). "Needs tests" is checked if there is a patch without tests, not an indication that tests are required. Also the documentation is incomplete. Please review the ​patch review checklist for all requirements.

[Alokik Roy]

Added tests and documentation

[Alokik Roy]

Requested Tests added.

[Mariusz Felisiak <felisiak.mariusz@…>]

In baf9604:

Fixed #16406 -- Added ResolveMatch.captured_kwargs and extra_kwargs.

Thanks Florian Apolloner for the review and implementation idea.