django/contrib/syndication/views.py
from inspect import getattr_static, unwrap
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
from django.utils.translation import get_language
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
language = 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.headers["Last-Modified"] = http_date(
feedgen.latest_post_date().timestamp()
)
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.
func = unwrap(attr)
try:
code = func.__code__
except AttributeError:
func = unwrap(attr.__call__)
code = func.__code__
# If function doesn't have arguments and it is not a static method,
# it was decorated without using @functools.wraps.
if not code.co_argcount and not isinstance(
getattr_static(self, func.__name__, None), staticmethod
):
raise ImproperlyConfigured(
f"Feed method {attname!r} decorated by {func.__name__!r} needs to "
f"use @functools.wraps."
)
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=self.language or get_language(),
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,
comments=self._get_dynamic_attr("item_comments", item),
categories=self._get_dynamic_attr("item_categories", item),
item_copyright=self._get_dynamic_attr("item_copyright", item),
**self.item_extra_kwargs(item),
)
return feed