from calendar import timegm
from django.conf import settings
from django.contrib.sites.shortcuts import get_current_site
from django.core.exceptions import ImproperlyConfigured, ObjectDoesNotExist
from django.http import Http404, HttpResponse
from django.template import TemplateDoesNotExist, loader
from django.utils import feedgenerator
from django.utils.encoding import iri_to_uri
from django.utils.html import escape
from django.utils.http import http_date
from django.utils.timezone import get_default_timezone, is_naive, make_aware
def add_domain(domain, url, secure=False):
protocol = 'https' if secure else 'http'
if url.startswith('//'):
# Support network-path reference (see #16753) - RSS requires a protocol
url = '%s:%s' % (protocol, url)
elif not url.startswith(('http://', 'https://', 'mailto:')):
url = iri_to_uri('%s://%s%s' % (protocol, domain, url))
return url
class FeedDoesNotExist(ObjectDoesNotExist):
pass
class Feed:
feed_type = feedgenerator.DefaultFeed
title_template = None
description_template = None
def __call__(self, request, *args, **kwargs):
try:
obj = self.get_object(request, *args, **kwargs)
except ObjectDoesNotExist:
raise Http404('Feed object does not exist.')
feedgen = self.get_feed(obj, request)
response = HttpResponse(content_type=feedgen.content_type)
if hasattr(self, 'item_pubdate') or hasattr(self, 'item_updateddate'):
# if item_pubdate or item_updateddate is defined for the feed, set
# header so as ConditionalGetMiddleware is able to send 304 NOT MODIFIED
response['Last-Modified'] = http_date(
timegm(feedgen.latest_post_date().utctimetuple()))
feedgen.write(response, 'utf-8')
return response
def item_title(self, item):
# Titles should be double escaped by default (see #6533)
return escape(str(item))
def item_description(self, item):
return str(item)
def item_link(self, item):
try:
return item.get_absolute_url()
except AttributeError:
raise ImproperlyConfigured(
'Give your %s class a get_absolute_url() method, or define an '
'item_link() method in your Feed class.' % item.__class__.__name__
)
def item_enclosures(self, item):
enc_url = self._get_dynamic_attr('item_enclosure_url', item)
if enc_url:
enc = feedgenerator.Enclosure(
url=str(enc_url),
length=str(self._get_dynamic_attr('item_enclosure_length', item)),
mime_type=str(self._get_dynamic_attr('item_enclosure_mime_type', item)),
)
return [enc]
return []
def _get_dynamic_attr(self, attname, obj, default=None):
try:
attr = getattr(self, attname)
except AttributeError:
return default
if callable(attr):
# Check co_argcount rather than try/excepting the function and
# catching the TypeError, because something inside the function
# may raise the TypeError. This technique is more accurate.
try:
code = attr.__code__
except AttributeError:
code = attr.__call__.__code__
if code.co_argcount == 2: # one argument is 'self'
return attr(obj)
else:
return attr()
return attr
def feed_extra_kwargs(self, obj):
"""
Return an extra keyword arguments dictionary that is used when
initializing the feed generator.
"""
return {}
def item_extra_kwargs(self, item):
"""
Return an extra keyword arguments dictionary that is used with
the `add_item` call of the feed generator.
"""
return {}
def get_object(self, request, *args, **kwargs):
return None
def get_context_data(self, **kwargs):
"""
Return a dictionary to use as extra context if either
``self.description_template`` or ``self.item_template`` are used.
Default implementation preserves the old behavior
of using {'obj': item, 'site': current_site} as the context.
"""
return {'obj': kwargs.get('item'), 'site': kwargs.get('site')}
def get_feed(self, obj, request):
"""
Return a feedgenerator.DefaultFeed object, fully populated, for
this feed. Raise FeedDoesNotExist for invalid parameters.
"""
current_site = get_current_site(request)
link = self._get_dynamic_attr('link', obj)
link = add_domain(current_site.domain, link, request.is_secure())
feed = self.feed_type(
title=self._get_dynamic_attr('title', obj),
subtitle=self._get_dynamic_attr('subtitle', obj),
link=link,
description=self._get_dynamic_attr('description', obj),
language=settings.LANGUAGE_CODE,
feed_url=add_domain(
current_site.domain,
self._get_dynamic_attr('feed_url', obj) or request.path,
request.is_secure(),
),
author_name=self._get_dynamic_attr('author_name', obj),
author_link=self._get_dynamic_attr('author_link', obj),
author_email=self._get_dynamic_attr('author_email', obj),
categories=self._get_dynamic_attr('categories', obj),
feed_copyright=self._get_dynamic_attr('feed_copyright', obj),
feed_guid=self._get_dynamic_attr('feed_guid', obj),
ttl=self._get_dynamic_attr('ttl', obj),
**self.feed_extra_kwargs(obj)
)
title_tmp = None
if self.title_template is not None:
try:
title_tmp = loader.get_template(self.title_template)
except TemplateDoesNotExist:
pass
description_tmp = None
if self.description_template is not None:
try:
description_tmp = loader.get_template(self.description_template)
except TemplateDoesNotExist:
pass
for item in self._get_dynamic_attr('items', obj):
context = self.get_context_data(item=item, site=current_site,
obj=obj, request=request)
if title_tmp is not None:
title = title_tmp.render(context, request)
else:
title = self._get_dynamic_attr('item_title', item)
if description_tmp is not None:
description = description_tmp.render(context, request)
else:
description = self._get_dynamic_attr('item_description', item)
link = add_domain(
current_site.domain,
self._get_dynamic_attr('item_link', item),
request.is_secure(),
)
enclosures = self._get_dynamic_attr('item_enclosures', item)
author_name = self._get_dynamic_attr('item_author_name', item)
if author_name is not None:
author_email = self._get_dynamic_attr('item_author_email', item)
author_link = self._get_dynamic_attr('item_author_link', item)
else:
author_email = author_link = None
tz = get_default_timezone()
pubdate = self._get_dynamic_attr('item_pubdate', item)
if pubdate and is_naive(pubdate):
pubdate = make_aware(pubdate, tz)
updateddate = self._get_dynamic_attr('item_updateddate', item)
if updateddate and is_naive(updateddate):
updateddate = make_aware(updateddate, tz)
feed.add_item(
title=title,
link=link,
description=description,
unique_id=self._get_dynamic_attr('item_guid', item, link),
unique_id_is_permalink=self._get_dynamic_attr(
'item_guid_is_permalink', item),
enclosures=enclosures,
pubdate=pubdate,
updateddate=updateddate,
author_name=author_name,
author_email=author_email,
author_link=author_link,
categories=self._get_dynamic_attr('item_categories', item),
item_copyright=self._get_dynamic_attr('item_copyright', item),
**self.item_extra_kwargs(item)
)
return feed
8月 23, 2019