+
−from django.db import models
+
−from django.utils.translation import ugettext_lazy as _
+
−
+
−SITE_CACHE = {}
+
−
+
−class SiteManager(models.Manager):
+
−    def get_current(self):
+
−        """
+
−        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.
+
−        """
+
−        from django.conf import settings
+
−        try:
+
−            sid = settings.SITE_ID
+
−        except AttributeError:
+
−            from django.core.exceptions import ImproperlyConfigured
+
−            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
+
−
+
−    def clear_cache(self):
+
−        """Clears the ``Site`` object cache."""
+
−        global SITE_CACHE
+
−        SITE_CACHE = {}
+
−
+
−class Site(models.Model):
+
−    domain = models.CharField(_('domain name'), max_length=100)
+
−    name = models.CharField(_('display name'), max_length=50)
+
−    objects = SiteManager()
+
−
+
−    class Meta:
+
−        db_table = 'django_site'
+
−        verbose_name = _('site')
+
−        verbose_name_plural = _('sites')
+
−        ordering = ('domain',)
+
−
+
−    def __unicode__(self):
+
−        return self.domain
+
−    
+
−    def delete(self):
+
−        pk = self.pk
+
−        super(Site, self).delete()
+
−        try:
+
−            del(SITE_CACHE[pk])
+
−        except KeyError:
+
−            pass
+
−
+
−class RequestSite(object):
+
−    """
+
−    A class that shares the primary interface of Site (i.e., it has
+
−    ``domain`` and ``name`` attributes) but gets its data from a Django
+
−    HttpRequest object rather than from a database.
+
−
+
−    The save() and delete() methods raise NotImplementedError.
+
−    """
+
−    def __init__(self, request):
+
−        self.domain = self.name = request.get_host()
+
−
+
−    def __unicode__(self):
+
−        return self.domain
+
−
+
−    def save(self, force_insert=False, force_update=False):
+
−        raise NotImplementedError('RequestSite cannot be saved.')
+
−
+
−    def delete(self):
+
−        raise NotImplementedError('RequestSite cannot be deleted.')