Fixed #25933 -- Allowed an unprefixed default language in i18n_patterns.

[urbaniak]

It's different than i18n_patterns by not prefixing the default language.

All other languages are prefixed similar to i18n_patterns.

It allows to add another language without changing the urls of the first
default language.

[gastlich]

+1

[charettes]

Hi @urbaniak, please follow the contribution guidelines and file a new ticket.

IMHO we don't need to introduce another function and a simple prefix kwarg defaulting to True in i18n_patterns should do. This will also require tests and a release note if it was to be accepted.

[urbaniak]

Simplified this as you suggested.

Opened the ticket on code.djangoproject.com - https://code.djangoproject.com/ticket/25933#ticket

I'll add tests, docs and release notes if that solution will be acceptable.

[urbaniak]

Updated it once again, it now uses a setting called I18N_PREFIX_DEFAULT_LANGUAGE.

It's much smaller and simpler change now.

[charettes]

We try to avoid adding new settings.

I think the kwarg approach was more appropriate as it allowed multiple instance of i18n_patterns to be used with different values for prefix. It also avoid relying on global state and make the implementation more contained.

If you're a fan of settings nothing prevent you from defining a I18N_PREFIX_DEFAULT_LANGUAGE in your project and passing it's value to i18n_patterns in your urls definition.

[urbaniak]

It's not possible (according to docs) to use multiple i18n_patterns.

Adds the language code prefix to every URL pattern within this
function. This may only be used in the root URLconf, not in an included
URLconf.

Adding a param there was confusing IMO cause then the i18n_patterns takes only *args as urls right now, so this additional param with some urls looks like that

urlpatterns += i18n_patterns(
    url(_(r'^contact/$'), views.contact),
    url(_(r'^about/$'), views.about),
    prefix_default_language=True,
)

It's also cleaner IMO cause right now we don't need to pass the prefix_default_language from i18n_patterns to the LocaleRegexURLResolver.

Here's the previous patch version:

diff --git a/django/conf/urls/i18n.py b/django/conf/urls/i18n.py
index 056b957..fed1a17 100644
--- a/django/conf/urls/i18n.py
+++ b/django/conf/urls/i18n.py
@@ -4,7 +4,7 @@ from django.core.urlresolvers import LocaleRegexURLResolver
 from django.views.i18n import set_language


-def i18n_patterns(*urls):
+def i18n_patterns(*urls, prefix_default_language=True):
     """
     Adds the language code prefix to every URL pattern within this
     function. This may only be used in the root URLconf, not in an included
@@ -12,7 +12,10 @@ def i18n_patterns(*urls):
     """
     if not settings.USE_I18N:
         return urls
-    return [LocaleRegexURLResolver(list(urls))]
+    return [LocaleRegexURLResolver(
+        list(urls),
+        prefix_default_language=prefix_default_language,
+    )]


 urlpatterns = [
diff --git a/django/core/urlresolvers.py b/django/core/urlresolvers.py
index d37a401..8103b64 100644
--- a/django/core/urlresolvers.py
+++ b/django/core/urlresolvers.py
@@ -12,6 +12,7 @@ import re
 from importlib import import_module
 from threading import local

+from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
 from django.http import Http404
 from django.utils import lru_cache, six
@@ -461,15 +462,23 @@ class LocaleRegexURLResolver(RegexURLResolver):
     Rather than taking a regex argument, we just override the ``regex``
     function to always return the active language-code as regex.
     """
-    def __init__(self, urlconf_name, default_kwargs=None, app_name=None, namespace=None):
+    def __init__(
+        self, urlconf_name, default_kwargs=None, app_name=None, namespace=None,
+        prefix_default_language=True
+    ):
         super(LocaleRegexURLResolver, self).__init__(
             None, urlconf_name, default_kwargs, app_name, namespace)
+        self.prefix_default_language = prefix_default_language

     @property
     def regex(self):
         language_code = get_language()
         if language_code not in self._regex_dict:
-            regex_compiled = re.compile('^%s/' % language_code, re.UNICODE)
+            regex_compiled = (
+                re.compile('', re.UNICODE) if language_code == settings.LANGUAGE_CODE and
+                not self.prefix_default_language else
+                re.compile('^%s/' % language_code, re.UNICODE)
+            )
             self._regex_dict[language_code] = regex_compiled
         return self._regex_dict[language_code]

[charettes]

It's not possible (according to docs) to use multiple i18n_patterns.

The doc states that you can't use i18n_patterns in included URLconf. It's not common to have multiple root URLconf but it's a pattern used in multi-host scenarios to route path from different hosts to completely different URLconf. I guess the documentation should be fixed to note that it may only be used in a root URLconf and LocaleMiddleware fixed to take into account request.urlconf when determining whether or not i18n_patterns are used.

While I agree the kwarg approach requires more adjustments than a global setting I'm not convinced it hurts readability that much.

[urbaniak]

Updated to the i18n_patterns param if that's more appropriate and have higher chances got merged upstream.

If that's ok and it has chances to get merged - I'll update docs and release notes later this week.

[timgraham]

The ticket is accepted -- will you have a chance to complete this soon or should we close the pull request for now?

[urbaniak]

Fixed one issues that I've found in meantime and updated docs.

That version of django is currently running on https://wipply.com, with default language set to en and additional pl language (which is not yet linked anywhere, but /pl/ is working).

[timgraham]

Branch needs to be rebased so it merges cleanly and tests are missing. See our patch review checklist and please send a pull request when you have a patch that meets all the requirements. Thanks!