"""
Syndication feed generation library -- used for generating RSS, etc.
Sample usage:
>>> from django.utils import feedgenerator
>>> feed = feedgenerator.Rss201rev2Feed(
... title="Poynter E-Media Tidbits",
... link="http://www.poynter.org/column.asp?id=31",
... description="A group Weblog by the sharpest minds in online media/journalism/publishing.",
... language="en",
... )
>>> feed.add_item(
... title="Hello",
... link="http://www.holovaty.com/test/",
... description="Testing."
... )
>>> with open('test.rss', 'w') as fp:
... feed.write(fp, 'utf-8')
For definitions of the different versions of RSS, see:
http://web.archive.org/web/20110718035220/http://diveintomark.org/archives/2004/02/04/incompatible-rss
"""
from __future__ import unicode_literals
import datetime
from django.utils.xmlutils import SimplerXMLGenerator
from django.utils.encoding import force_text, iri_to_uri
from django.utils import datetime_safe
from django.utils import six
from django.utils.six import StringIO
from django.utils.six.moves.urllib.parse import urlparse
from django.utils.timezone import is_aware
def rfc2822_date(date):
# We can't use strftime() because it produces locale-dependent results, so
# we have to map english month and day names manually
months = ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec',)
days = ('Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun')
# Support datetime objects older than 1900
date = datetime_safe.new_datetime(date)
# We do this ourselves to be timezone aware, email.Utils is not tz aware.
dow = days[date.weekday()]
month = months[date.month - 1]
time_str = date.strftime('%s, %%d %s %%Y %%H:%%M:%%S ' % (dow, month))
if six.PY2: # strftime returns a byte string in Python 2
time_str = time_str.decode('utf-8')
if is_aware(date):
offset = date.tzinfo.utcoffset(date)
timezone = (offset.days * 24 * 60) + (offset.seconds // 60)
hour, minute = divmod(timezone, 60)
return time_str + '%+03d%02d' % (hour, minute)
else:
return time_str + '-0000'
def rfc3339_date(date):
# Support datetime objects older than 1900
date = datetime_safe.new_datetime(date)
time_str = date.strftime('%Y-%m-%dT%H:%M:%S')
if six.PY2: # strftime returns a byte string in Python 2
time_str = time_str.decode('utf-8')
if is_aware(date):
offset = date.tzinfo.utcoffset(date)
timezone = (offset.days * 24 * 60) + (offset.seconds // 60)
hour, minute = divmod(timezone, 60)
return time_str + '%+03d:%02d' % (hour, minute)
else:
return time_str + 'Z'
[docs]def get_tag_uri(url, date):
"""
Creates a TagURI.
See http://web.archive.org/web/20110514113830/http://diveintomark.org/archives/2004/05/28/howto-atom-id
"""
bits = urlparse(url)
d = ''
if date is not None:
d = ',%s' % datetime_safe.new_datetime(date).strftime('%Y-%m-%d')
return 'tag:%s%s:%s/%s' % (bits.hostname, d, bits.path, bits.fragment)
[docs]class SyndicationFeed(object):
"Base class for all syndication feeds. Subclasses should provide write()"
[docs] def __init__(self, title, link, description, language=None, author_email=None,
author_name=None, author_link=None, subtitle=None, categories=None,
feed_url=None, feed_copyright=None, feed_guid=None, ttl=None, **kwargs):
to_unicode = lambda s: force_text(s, strings_only=True)
if categories:
categories = [force_text(c) for c in categories]
if ttl is not None:
# Force ints to unicode
ttl = force_text(ttl)
self.feed = {
'title': to_unicode(title),
'link': iri_to_uri(link),
'description': to_unicode(description),
'language': to_unicode(language),
'author_email': to_unicode(author_email),
'author_name': to_unicode(author_name),
'author_link': iri_to_uri(author_link),
'subtitle': to_unicode(subtitle),
'categories': categories or (),
'feed_url': iri_to_uri(feed_url),
'feed_copyright': to_unicode(feed_copyright),
'id': feed_guid or link,
'ttl': ttl,
}
self.feed.update(kwargs)
self.items = []
[docs] def add_item(self, title, link, description, author_email=None,
author_name=None, author_link=None, pubdate=None, comments=None,
unique_id=None, unique_id_is_permalink=None, enclosure=None,
categories=(), item_copyright=None, ttl=None, **kwargs):
"""
Adds an item to the feed. All args are expected to be Python Unicode
objects except pubdate, which is a datetime.datetime object, and
enclosure, which is an instance of the Enclosure class.
"""
to_unicode = lambda s: force_text(s, strings_only=True)
if categories:
categories = [to_unicode(c) for c in categories]
if ttl is not None:
# Force ints to unicode
ttl = force_text(ttl)
item = {
'title': to_unicode(title),
'link': iri_to_uri(link),
'description': to_unicode(description),
'author_email': to_unicode(author_email),
'author_name': to_unicode(author_name),
'author_link': iri_to_uri(author_link),
'pubdate': pubdate,
'comments': to_unicode(comments),
'unique_id': to_unicode(unique_id),
'unique_id_is_permalink': unique_id_is_permalink,
'enclosure': enclosure,
'categories': categories or (),
'item_copyright': to_unicode(item_copyright),
'ttl': ttl,
}
item.update(kwargs)
self.items.append(item)
[docs] def root_attributes(self):
"""
Return extra attributes to place on the root (i.e. feed/channel) element.
Called from write().
"""
return {}
[docs] def add_root_elements(self, handler):
"""
Add elements in the root (i.e. feed/channel) element. Called
from write().
"""
pass
[docs] def item_attributes(self, item):
"""
Return extra attributes to place on each item (i.e. item/entry) element.
"""
return {}
[docs] def add_item_elements(self, handler, item):
"""
Add elements on each item (i.e. item/entry) element.
"""
pass
[docs] def write(self, outfile, encoding):
"""
Outputs the feed in the given encoding to outfile, which is a file-like
object. Subclasses should override this.
"""
raise NotImplementedError
[docs] def writeString(self, encoding):
"""
Returns the feed in the given encoding as a string.
"""
s = StringIO()
self.write(s, encoding)
return s.getvalue()
[docs] def latest_post_date(self):
"""
Returns the latest item's pubdate. If none of them have a pubdate,
this returns the current date/time.
"""
updates = [i['pubdate'] for i in self.items if i['pubdate'] is not None]
if len(updates) > 0:
updates.sort()
return updates[-1]
else:
return datetime.datetime.now()
[docs]class Enclosure(object):
"Represents an RSS enclosure"
def __init__(self, url, length, mime_type):
"All args are expected to be Python Unicode objects"
self.length, self.mime_type = length, mime_type
self.url = iri_to_uri(url)
[docs]class RssFeed(SyndicationFeed):
mime_type = 'application/rss+xml; charset=utf-8'
def write(self, outfile, encoding):
handler = SimplerXMLGenerator(outfile, encoding)
handler.startDocument()
handler.startElement("rss", self.rss_attributes())
handler.startElement("channel", self.root_attributes())
self.add_root_elements(handler)
self.write_items(handler)
self.endChannelElement(handler)
handler.endElement("rss")
def rss_attributes(self):
return {"version": self._version,
"xmlns:atom": "http://www.w3.org/2005/Atom"}
def write_items(self, handler):
for item in self.items:
handler.startElement('item', self.item_attributes(item))
self.add_item_elements(handler, item)
handler.endElement("item")
def add_root_elements(self, handler):
handler.addQuickElement("title", self.feed['title'])
handler.addQuickElement("link", self.feed['link'])
handler.addQuickElement("description", self.feed['description'])
if self.feed['feed_url'] is not None:
handler.addQuickElement("atom:link", None,
{"rel": "self", "href": self.feed['feed_url']})
if self.feed['language'] is not None:
handler.addQuickElement("language", self.feed['language'])
for cat in self.feed['categories']:
handler.addQuickElement("category", cat)
if self.feed['feed_copyright'] is not None:
handler.addQuickElement("copyright", self.feed['feed_copyright'])
handler.addQuickElement("lastBuildDate", rfc2822_date(self.latest_post_date()))
if self.feed['ttl'] is not None:
handler.addQuickElement("ttl", self.feed['ttl'])
def endChannelElement(self, handler):
handler.endElement("channel")
[docs]class RssUserland091Feed(RssFeed):
_version = "0.91"
def add_item_elements(self, handler, item):
handler.addQuickElement("title", item['title'])
handler.addQuickElement("link", item['link'])
if item['description'] is not None:
handler.addQuickElement("description", item['description'])
[docs]class Rss201rev2Feed(RssFeed):
# Spec: http://blogs.law.harvard.edu/tech/rss
_version = "2.0"
def add_item_elements(self, handler, item):
handler.addQuickElement("title", item['title'])
handler.addQuickElement("link", item['link'])
if item['description'] is not None:
handler.addQuickElement("description", item['description'])
# Author information.
if item["author_name"] and item["author_email"]:
handler.addQuickElement("author", "%s (%s)" % \
(item['author_email'], item['author_name']))
elif item["author_email"]:
handler.addQuickElement("author", item["author_email"])
elif item["author_name"]:
handler.addQuickElement("dc:creator", item["author_name"], {"xmlns:dc": "http://purl.org/dc/elements/1.1/"})
if item['pubdate'] is not None:
handler.addQuickElement("pubDate", rfc2822_date(item['pubdate']))
if item['comments'] is not None:
handler.addQuickElement("comments", item['comments'])
if item['unique_id'] is not None:
guid_attrs = {}
if isinstance(item.get('unique_id_is_permalink'), bool):
guid_attrs['isPermaLink'] = str(
item['unique_id_is_permalink']).lower()
handler.addQuickElement("guid", item['unique_id'], guid_attrs)
if item['ttl'] is not None:
handler.addQuickElement("ttl", item['ttl'])
# Enclosure.
if item['enclosure'] is not None:
handler.addQuickElement("enclosure", '',
{"url": item['enclosure'].url, "length": item['enclosure'].length,
"type": item['enclosure'].mime_type})
# Categories.
for cat in item['categories']:
handler.addQuickElement("category", cat)
[docs]class Atom1Feed(SyndicationFeed):
# Spec: http://atompub.org/2005/07/11/draft-ietf-atompub-format-10.html
mime_type = 'application/atom+xml; charset=utf-8'
ns = "http://www.w3.org/2005/Atom"
def write(self, outfile, encoding):
handler = SimplerXMLGenerator(outfile, encoding)
handler.startDocument()
handler.startElement('feed', self.root_attributes())
self.add_root_elements(handler)
self.write_items(handler)
handler.endElement("feed")
def root_attributes(self):
if self.feed['language'] is not None:
return {"xmlns": self.ns, "xml:lang": self.feed['language']}
else:
return {"xmlns": self.ns}
def add_root_elements(self, handler):
handler.addQuickElement("title", self.feed['title'])
handler.addQuickElement("link", "", {"rel": "alternate", "href": self.feed['link']})
if self.feed['feed_url'] is not None:
handler.addQuickElement("link", "", {"rel": "self", "href": self.feed['feed_url']})
handler.addQuickElement("id", self.feed['id'])
handler.addQuickElement("updated", rfc3339_date(self.latest_post_date()))
if self.feed['author_name'] is not None:
handler.startElement("author", {})
handler.addQuickElement("name", self.feed['author_name'])
if self.feed['author_email'] is not None:
handler.addQuickElement("email", self.feed['author_email'])
if self.feed['author_link'] is not None:
handler.addQuickElement("uri", self.feed['author_link'])
handler.endElement("author")
if self.feed['subtitle'] is not None:
handler.addQuickElement("subtitle", self.feed['subtitle'])
for cat in self.feed['categories']:
handler.addQuickElement("category", "", {"term": cat})
if self.feed['feed_copyright'] is not None:
handler.addQuickElement("rights", self.feed['feed_copyright'])
def write_items(self, handler):
for item in self.items:
handler.startElement("entry", self.item_attributes(item))
self.add_item_elements(handler, item)
handler.endElement("entry")
def add_item_elements(self, handler, item):
handler.addQuickElement("title", item['title'])
handler.addQuickElement("link", "", {"href": item['link'], "rel": "alternate"})
if item['pubdate'] is not None:
handler.addQuickElement("updated", rfc3339_date(item['pubdate']))
# Author information.
if item['author_name'] is not None:
handler.startElement("author", {})
handler.addQuickElement("name", item['author_name'])
if item['author_email'] is not None:
handler.addQuickElement("email", item['author_email'])
if item['author_link'] is not None:
handler.addQuickElement("uri", item['author_link'])
handler.endElement("author")
# Unique ID.
if item['unique_id'] is not None:
unique_id = item['unique_id']
else:
unique_id = get_tag_uri(item['link'], item['pubdate'])
handler.addQuickElement("id", unique_id)
# Summary.
if item['description'] is not None:
handler.addQuickElement("summary", item['description'], {"type": "html"})
# Enclosure.
if item['enclosure'] is not None:
handler.addQuickElement("link", '',
{"rel": "enclosure",
"href": item['enclosure'].url,
"length": item['enclosure'].length,
"type": item['enclosure'].mime_type})
# Categories.
for cat in item['categories']:
handler.addQuickElement("category", "", {"term": cat})
# Rights.
if item['item_copyright'] is not None:
handler.addQuickElement("rights", item['item_copyright'])
# This isolates the decision of what the system default is, so calling code can
# do "feedgenerator.DefaultFeed" instead of "feedgenerator.Rss201rev2Feed".
DefaultFeed = Rss201rev2Feed
Oct 03, 2017