from calendar import timegm from contextlib import suppress 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: with suppress(TemplateDoesNotExist): title_tmp = loader.get_template(self.title_template) description_tmp = None if self.description_template is not None: with suppress(TemplateDoesNotExist): description_tmp = loader.get_template(self.description_template) 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