| author |
Steve Losh <steve@stevelosh.com> |
| date |
Fri, 11 Jun 2010 20:14:01 -0400 |
| parents |
(none) |
| children |
(none) |
# -*- coding: utf-8 -*-
"""
werkzeug.contrib.atom
~~~~~~~~~~~~~~~~~~~~~
This module provides a class called :class:`AtomFeed` which can be
used to generate feeds in the Atom syndication format (see :rfc:`4287`).
Example::
def atom_feed(request):
feed = AtomFeed("My Blog", feed_url=request.url,
url=request.host_url,
subtitle="My example blog for a feed test.")
for post in Post.query.limit(10).all():
feed.add(post.title, post.body, content_type='html',
author=post.author, url=post.url, id=post.uid,
updated=post.last_update, published=post.pub_date)
return feed.get_response()
:copyright: (c) 2010 by the Werkzeug Team, see AUTHORS for more details.
:license: BSD, see LICENSE for more details.
"""
from datetime import datetime
from werkzeug.utils import escape
from werkzeug.wrappers import BaseResponse
XHTML_NAMESPACE = 'http://www.w3.org/1999/xhtml'
def _make_text_block(name, content, content_type=None):
"""Helper function for the builder that creates an XML text block."""
if content_type == 'xhtml':
return u'<%s type="xhtml"><div xmlns="%s">%s</div></%s>\n' % \
(name, XHTML_NAMESPACE, content, name)
if not content_type:
return u'<%s>%s</%s>\n' % (name, escape(content), name)
return u'<%s type="%s">%s</%s>\n' % (name, content_type,
escape(content), name)
def format_iso8601(obj):
"""Format a datetime object for iso8601"""
return obj.strftime('%Y-%m-%dT%H:%M:%SZ')
class AtomFeed(object):
"""A helper class that creates Atom feeds.
:param title: the title of the feed. Required.
:param title_type: the type attribute for the title element. One of
``'html'``, ``'text'`` or ``'xhtml'``.
:param url: the url for the feed (not the url *of* the feed)
:param id: a globally unique id for the feed. Must be an URI. If
not present the `feed_url` is used, but one of both is
required.
:param updated: the time the feed was modified the last time. Must
be a :class:`datetime.datetime` object. If not
present the latest entry's `updated` is used.
:param feed_url: the URL to the feed. Should be the URL that was
requested.
:param author: the author of the feed. Must be either a string (the
name) or a dict with name (required) and uri or
email (both optional). Can be a list of (may be
mixed, too) strings and dicts, too, if there are
multiple authors. Required if not every entry has an
author element.
:param icon: an icon for the feed.
:param logo: a logo for the feed.
:param rights: copyright information for the feed.
:param rights_type: the type attribute for the rights element. One of
``'html'``, ``'text'`` or ``'xhtml'``. Default is
``'text'``.
:param subtitle: a short description of the feed.
:param subtitle_type: the type attribute for the subtitle element.
One of ``'text'``, ``'html'``, ``'text'``
or ``'xhtml'``. Default is ``'text'``.
:param links: additional links. Must be a list of dictionaries with
href (required) and rel, type, hreflang, title, length
(all optional)
:param generator: the software that generated this feed. This must be
a tuple in the form ``(name, url, version)``. If
you don't want to specify one of them, set the item
to `None`.
:param entries: a list with the entries for the feed. Entries can also
be added later with :meth:`add`.
For more information on the elements see
http://www.atomenabled.org/developers/syndication/
Everywhere where a list is demanded, any iterable can be used.
"""
default_generator = ('Werkzeug', None, None)
def __init__(self, title=None, entries=None, **kwargs):
self.title = title
self.title_type = kwargs.get('title_type', 'text')
self.url = kwargs.get('url')
self.feed_url = kwargs.get('feed_url', self.url)
self.id = kwargs.get('id', self.feed_url)
self.updated = kwargs.get('updated')
self.author = kwargs.get('author', ())
self.icon = kwargs.get('icon')
self.logo = kwargs.get('logo')
self.rights = kwargs.get('rights')
self.rights_type = kwargs.get('rights_type')
self.subtitle = kwargs.get('subtitle')
self.subtitle_type = kwargs.get('subtitle_type', 'text')
self.generator = kwargs.get('generator')
if self.generator is None:
self.generator = self.default_generator
self.links = kwargs.get('links', [])
self.entries = entries and list(entries) or []
if not hasattr(self.author, '__iter__') \
or isinstance(self.author, (basestring, dict)):
self.author = [self.author]
for i, author in enumerate(self.author):
if not isinstance(author, dict):
self.author[i] = {'name': author}
if not self.title:
raise ValueError('title is required')
if not self.id:
raise ValueError('id is required')
for author in self.author:
if 'name' not in author:
raise TypeError('author must contain at least a name')
def add(self, *args, **kwargs):
"""Add a new entry to the feed. This function can either be called
with a :class:`FeedEntry` or some keyword and positional arguments
that are forwarded to the :class:`FeedEntry` constructor.
"""
if len(args) == 1 and not kwargs and isinstance(args[0], FeedEntry):
self.entries.append(args[0])
else:
kwargs['feed_url'] = self.feed_url
self.entries.append(FeedEntry(*args, **kwargs))
def __repr__(self):
return '<%s %r (%d entries)>' % (
self.__class__.__name__,
self.title,
len(self.entries)
)
def generate(self):
"""Return a generator that yields pieces of XML."""
# atom demands either an author element in every entry or a global one
if not self.author:
if False in map(lambda e: bool(e.author), self.entries):
self.author = ({'name': u'unbekannter Autor'},)
if not self.updated:
dates = sorted([entry.updated for entry in self.entries])
self.updated = dates and dates[-1] or datetime.utcnow()
yield u'<?xml version="1.0" encoding="utf-8"?>\n'
yield u'<feed xmlns="http://www.w3.org/2005/Atom">\n'
yield ' ' + _make_text_block('title', self.title, self.title_type)
yield u' <id>%s</id>\n' % escape(self.id)
yield u' <updated>%s</updated>\n' % format_iso8601(self.updated)
if self.url:
yield u' <link href="%s" />\n' % escape(self.url, True)
if self.feed_url:
yield u' <link href="%s" rel="self" />\n' % \
escape(self.feed_url, True)
for link in self.links:
yield u' <link %s/>\n' % ''.join('%s="%s" ' % \
(k, escape(link[k], True)) for k in link)
for author in self.author:
yield u' <author>\n'
yield u' <name>%s</name>\n' % escape(author['name'])
if 'uri' in author:
yield u' <uri>%s</uri>\n' % escape(author['uri'])
if 'email' in author:
yield ' <email>%s</email>\n' % escape(author['email'])
yield ' </author>\n'
if self.subtitle:
yield ' ' + _make_text_block('subtitle', self.subtitle,
self.subtitle_type)
if self.icon:
yield u' <icon>%s</icon>\n' % escape(self.icon)
if self.logo:
yield u' <logo>%s</logo>\n' % escape(self.logo)
if self.rights:
yield ' ' + _make_text_block('rights', self.rights,
self.rights_type)
generator_name, generator_url, generator_version = self.generator
if generator_name or generator_url or generator_version:
tmp = [u' <generator']
if generator_url:
tmp.append(u' uri="%s"' % escape(generator_url, True))
if generator_version:
tmp.append(u' version="%s"' % escape(generator_version, True))
tmp.append(u'>%s</generator>\n' % escape(generator_name))
yield u''.join(tmp)
for entry in self.entries:
for line in entry.generate():
yield u' ' + line
yield u'</feed>\n'
def to_string(self):
"""Convert the feed into a string."""
return u''.join(self.generate())
def get_response(self):
"""Return a response object for the feed."""
return BaseResponse(self.to_string(), mimetype='application/atom+xml')
def __call__(self, environ, start_response):
"""Use the class as WSGI response object."""
return self.get_response()(environ, start_response)
def __unicode__(self):
return self.to_string()
def __str__(self):
return self.to_string().encode('utf-8')
class FeedEntry(object):
"""Represents a single entry in a feed.
:param title: the title of the entry. Required.
:param title_type: the type attribute for the title element. One of
``'html'``, ``'text'`` or ``'xhtml'``.
:param content: the content of the entry.
:param content_type: the type attribute for the content element. One
of ``'html'``, ``'text'`` or ``'xhtml'``.
:param summary: a summary of the entry's content.
:param summary_type: the type attribute for the summary element. One
of ``'html'``, ``'text'`` or ``'xhtml'``.
:param url: the url for the entry.
:param id: a globally unique id for the entry. Must be an URI. If
not present the URL is used, but one of both is required.
:param updated: the time the entry was modified the last time. Must
be a :class:`datetime.datetime` object. Required.
:param author: the author of the feed. Must be either a string (the
name) or a dict with name (required) and uri or
email (both optional). Can be a list of (may be
mixed, too) strings and dicts, too, if there are
multiple authors. Required if not every entry has an
author element.
:param published: the time the entry was initially published. Must
be a :class:`datetime.datetime` object.
:param rights: copyright information for the entry.
:param rights_type: the type attribute for the rights element. One of
``'html'``, ``'text'`` or ``'xhtml'``. Default is
``'text'``.
:param links: additional links. Must be a list of dictionaries with
href (required) and rel, type, hreflang, title, length
(all optional)
:param xml_base: The xml base (url) for this feed item. If not provided
it will default to the item url.
For more information on the elements see
http://www.atomenabled.org/developers/syndication/
Everywhere where a list is demanded, any iterable can be used.
"""
def __init__(self, title=None, content=None, feed_url=None, **kwargs):
self.title = title
self.title_type = kwargs.get('title_type', 'text')
self.content = content
self.content_type = kwargs.get('content_type', 'html')
self.url = kwargs.get('url')
self.id = kwargs.get('id', self.url)
self.updated = kwargs.get('updated')
self.summary = kwargs.get('summary')
self.summary_type = kwargs.get('summary_type', 'html')
self.author = kwargs.get('author')
self.published = kwargs.get('published')
self.rights = kwargs.get('rights')
self.links = kwargs.get('links', [])
self.xml_base = kwargs.get('xml_base', feed_url)
if not hasattr(self.author, '__iter__') \
or isinstance(self.author, (basestring, dict)):
self.author = [self.author]
for i, author in enumerate(self.author):
if not isinstance(author, dict):
self.author[i] = {'name': author}
if not self.title:
raise ValueError('title is required')
if not self.id:
raise ValueError('id is required')
if not self.updated:
raise ValueError('updated is required')
def __repr__(self):
return '<%s %r>' % (
self.__class__.__name__,
self.title
)
def generate(self):
"""Yields pieces of ATOM XML."""
base = ''
if self.xml_base:
base = ' xml:base="%s"' % escape(self.xml_base, True)
yield u'<entry%s>\n' % base
yield u' ' + _make_text_block('title', self.title, self.title_type)
yield u' <id>%s</id>\n' % escape(self.id)
yield u' <updated>%s</updated>\n' % format_iso8601(self.updated)
if self.published:
yield u' <published>%s</published>\n' % \
format_iso8601(self.published)
if self.url:
yield u' <link href="%s" />\n' % escape(self.url)
for author in self.author:
yield u' <author>\n'
yield u' <name>%s</name>\n' % escape(author['name'])
if 'uri' in author:
yield u' <uri>%s</uri>\n' % escape(author['uri'])
if 'email' in author:
yield u' <email>%s</email>\n' % escape(author['email'])
yield u' </author>\n'
for link in self.links:
yield u' <link %s/>\n' % ''.join('%s="%s" ' % \
(k, escape(link[k], True)) for k in link)
if self.summary:
yield u' ' + _make_text_block('summary', self.summary,
self.summary_type)
if self.content:
yield u' ' + _make_text_block('content', self.content,
self.content_type)
yield u'</entry>\n'
def to_string(self):
"""Convert the feed item into a unicode object."""
return u''.join(self.generate())
def __unicode__(self):
return self.to_string()
def __str__(self):
return self.to_string().encode('utf-8')