Ticket #15089: 0001-Make-settings.SITE_ID-optional-for-django.contrib.si.patch

django/contrib/sites/models.py

@@ -34 +34 @@
 
 class SiteManager(models.Manager):
 
-    def get_current(self):
+    def _get_site_by_id(self, sid):
+        if not sid in SITE_CACHE:
+            site = self.get(pk=sid)
+            SITE_CACHE[sid] = site
+        return SITE_CACHE[sid]
+
+    def _get_site_by_request(self, request):
+        host = request.get_host()
+        if not host in SITE_CACHE:
+            site = self.get(domain__iexact=host)
+            SITE_CACHE[host] = site
+        return SITE_CACHE[host]
+
+    def get_current(self, request=None):
         """
         Returns the current ``Site`` based on the SITE_ID in the
-        project's settings. The ``Site`` object is cached the first
-        time it's retrieved from the database.
+        project's settings if request is None. Otherwise return the
+        the current ``Site`` matching its domain with request's host
+        The ``Site`` object is cached the first time it's retrieved
+        from the database.
         """
-        from django.conf import settings
-        try:
-            sid = settings.SITE_ID
-        except AttributeError:
-            raise ImproperlyConfigured(
-                "You're using the Django \"sites framework\" without having "
-                "set the SITE_ID setting. Create a site in your database and "
-                "set the SITE_ID setting to fix this error.")
-        try:
-            current_site = SITE_CACHE[sid]
-        except KeyError:
-            current_site = self.get(pk=sid)
-            SITE_CACHE[sid] = current_site
-        return current_site
+        if request:
+            return self._get_site_by_request(request)
+        else:
+            from django.conf import settings
+            try:
+                sid = settings.SITE_ID
+            except AttributeError:
+                raise ImproperlyConfigured(
+                    "You're using the Django \"sites framework\" without having "
+                    "set the SITE_ID setting. Create a site in your database and "
+                    "set the SITE_ID setting to fix this error.")
+            return self._get_site_by_id(sid)
 
     def clear_cache(self):
         """Clears the ``Site`` object cache."""

django/contrib/sites/shortcuts.py

@@ -12 +12 @@
     # the Site models when django.contrib.sites isn't installed.
     if apps.is_installed('django.contrib.sites'):
         from .models import Site
-        return Site.objects.get_current()
+        from django.conf import settings
+        req = None if hasattr(settings, 'SITE_ID') else request
+        return Site.objects.get_current(req)
     else:
         from .requests import RequestSite
         return RequestSite(request)

django/contrib/sites/tests.py

@@ -71 +71 @@
             self.assertIsInstance(site, RequestSite)
             self.assertEqual(site.name, "example.com")
 
+    @override_settings(SITE_ID='', ALLOWED_HOSTS=['example.com'])
+    def test_get_current_site_no_site_id(self):
+        request = HttpRequest()
+        request.META = {
+            "SERVER_NAME": "example.com",
+            "SERVER_PORT": "80",
+        }
+        del settings.SITE_ID
+        site = get_current_site(request)
+        self.assertEqual(site.name, "example.com")
+
     def test_domain_name_with_whitespaces(self):
         # Regression for #17320
         # Domain names are not allowed contain whitespace characters

docs/ref/contrib/sites.txt

@@ -18 +18 @@
 .. class:: models.Site
 
     A model for storing the ``domain`` and ``name`` attributes of a Web site.
-    The :setting:`SITE_ID` setting specifies the database ID of the
-    :class:`~django.contrib.sites.models.Site` object (accessible using
-    the automatically added ``id`` attribute) associated with that
-    particular settings file.
 
     .. attribute:: domain
 
@@ -31 +27 @@
 
         A human-readable "verbose" name for the Web site.
 
+The :setting:`SITE_ID` setting specifies the database ID of the
+:class:`~django.contrib.sites.models.Site` object associated with that
+particular settings file. It is possible to omit it, but then the
+:func:`~django.contrib.sites.shortcuts.get_current_site` function will always
+try to get the current site by comparing the
+:attr:`~django.contrib.sites.models.Site.domain` with the host name from
+the :meth:`~django.http.HttpRequest.get_host` method.
+
 How you use this is up to you, but Django uses it in a couple of ways
 automatically via simple conventions.
 
@@ -308 +312 @@
 automatically filters its queries to include only objects associated
 with the current :class:`~django.contrib.sites.models.Site`.
 
+.. admonition:: Mandatory SITE_ID
+
+    The ``CurrentSiteManager`` is only usable when the :setting:`SITE_ID`
+    setting is defined in your settings.
+
 Use :class:`~django.contrib.sites.managers.CurrentSiteManager` by adding it to
 your model explicitly. For example::