-from __future__ import unicode_literals

-

-import string

-

-from django.db import models

-from django.db.models.signals import pre_save, pre_delete

-from django.utils.translation import ugettext_lazy as _

-from django.utils.encoding import python_2_unicode_compatible

-from django.core.exceptions import ValidationError

-

-

-SITE_CACHE = {}

-

-

-def _simple_domain_name_validator(value):

- """

- Validates that the given value contains no whitespaces to prevent common

- typos.

- """

- if not value:

- return

- checks = ((s in value) for s in string.whitespace)

- if any(checks):

- raise ValidationError(

- _("The domain name cannot contain any spaces or tabs."),

- code='invalid',

- )

-

-

-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 = {}

-

-

-@python_2_unicode_compatible

-class Site(models.Model):

-

- domain = models.CharField(_('domain name'), max_length=100,

- validators=[_simple_domain_name_validator])

- 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 __str__(self):

- return self.domain

-

-

-@python_2_unicode_compatible

-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 __str__(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.')

-

-

-def get_current_site(request):

- """

- Checks if contrib.sites is installed and returns either the current

- ``Site`` object or a ``RequestSite`` object based on the request.

- """

- if Site._meta.installed:

- current_site = Site.objects.get_current()

- else:

- current_site = RequestSite(request)

- return current_site

-

-

-def clear_site_cache(sender, **kwargs):

- """

- Clears the cache (if primed) each time a site is saved or deleted

- """

- instance = kwargs['instance']

- try:

- del SITE_CACHE[instance.pk]

- except KeyError:

- pass

-pre_save.connect(clear_site_cache, sender=Site)

-pre_delete.connect(clear_site_cache, sender=Site)