feedgenerator.py :  » Content-Management-Systems » PyLucid » PyLucid_standalone » django » utils » Python Open Source

Home
Python Open Source
1.3.1.2 Python
2.Ajax
3.Aspect Oriented
4.Blog
5.Build
6.Business Application
7.Chart Report
8.Content Management Systems
9.Cryptographic
10.Database
11.Development
12.Editor
13.Email
14.ERP
15.Game 2D 3D
16.GIS
17.GUI
18.IDE
19.Installer
20.IRC
21.Issue Tracker
22.Language Interface
23.Log
24.Math
25.Media Sound Audio
26.Mobile
27.Network
28.Parser
29.PDF
30.Project Management
31.RSS
32.Search
33.Security
34.Template Engines
35.Test
36.UML
37.USB Serial
38.Web Frameworks
39.Web Server
40.Web Services
41.Web Unit
42.Wiki
43.Windows
44.XML
Python Open Source » Content Management Systems » PyLucid 
PyLucid » PyLucid_standalone » django » utils » feedgenerator.py
"""
Syndication feed generation library -- used for generating RSS, etc.

Sample usage:

>>> from django.utils import feedgenerator
>>> feed = feedgenerator.Rss201rev2Feed(
...     title=u"Poynter E-Media Tidbits",
...     link=u"http://www.poynter.org/column.asp?id=31",
...     description=u"A group weblog by the sharpest minds in online media/journalism/publishing.",
...     language=u"en",
... )
>>> feed.add_item(title="Hello", link=u"http://www.holovaty.com/test/", description="Testing.")
>>> fp = open('test.rss', 'w')
>>> feed.write(fp, 'utf-8')
>>> fp.close()

For definitions of the different versions of RSS, see:
http://diveintomark.org/archives/2004/02/04/incompatible-rss
"""

import datetime
import urlparse
from django.utils.xmlutils import SimplerXMLGenerator
from django.utils.encoding import force_unicode,iri_to_uri

def rfc2822_date(date):
    # We do this ourselves to be timezone aware, email.Utils is not tz aware.
    if date.tzinfo:
        time_str = date.strftime('%a, %d %b %Y %H:%M:%S ')
        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 date.strftime('%a, %d %b %Y %H:%M:%S -0000')

def rfc3339_date(date):
    if date.tzinfo:
        time_str = date.strftime('%Y-%m-%dT%H:%M:%S')
        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 date.strftime('%Y-%m-%dT%H:%M:%SZ')

def get_tag_uri(url, date):
    """
    Creates a TagURI.

    See http://diveintomark.org/archives/2004/05/28/howto-atom-id
    """
    url_split = urlparse.urlparse(url)

    # Python 2.4 didn't have named attributes on split results or the hostname.
    hostname = getattr(url_split, 'hostname', url_split[1].split(':')[0])
    path = url_split[2]
    fragment = url_split[5]

    d = ''
    if date is not None:
        d = ',%s' % date.strftime('%Y-%m-%d')
    return u'tag:%s%s:%s/%s' % (hostname, d, path, fragment)

class SyndicationFeed(object):
    "Base class for all syndication feeds. Subclasses should provide write()"
    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_unicode(s, strings_only=True)
        if categories:
            categories = [force_unicode(c) for c in categories]
        if ttl is not None:
            # Force ints to unicode
            ttl = force_unicode(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 = []

    def add_item(self, title, link, description, author_email=None,
        author_name=None, author_link=None, pubdate=None, comments=None,
        unique_id=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_unicode(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_unicode(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),
            'enclosure': enclosure,
            'categories': categories or (),
            'item_copyright': to_unicode(item_copyright),
            'ttl': ttl,
        }
        item.update(kwargs)
        self.items.append(item)

    def num_items(self):
        return len(self.items)

    def root_attributes(self):
        """
        Return extra attributes to place on the root (i.e. feed/channel) element.
        Called from write().
        """
        return {}

    def add_root_elements(self, handler):
        """
        Add elements in the root (i.e. feed/channel) element. Called
        from write().
        """
        pass

    def item_attributes(self, item):
        """
        Return extra attributes to place on each item (i.e. item/entry) element.
        """
        return {}

    def add_item_elements(self, handler, item):
        """
        Add elements on each item (i.e. item/entry) element.
        """
        pass

    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

    def writeString(self, encoding):
        """
        Returns the feed in the given encoding as a string.
        """
        from StringIO import StringIO
        s = StringIO()
        self.write(s, encoding)
        return s.getvalue()

    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()

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)

class RssFeed(SyndicationFeed):
    mime_type = 'application/rss+xml'
    def write(self, outfile, encoding):
        handler = SimplerXMLGenerator(outfile, encoding)
        handler.startDocument()
        handler.startElement(u"rss", self.rss_attributes())
        handler.startElement(u"channel", self.root_attributes())
        self.add_root_elements(handler)
        self.write_items(handler)
        self.endChannelElement(handler)
        handler.endElement(u"rss")

    def rss_attributes(self):
        return {u"version": self._version,
                u"xmlns:atom": u"http://www.w3.org/2005/Atom"}

    def write_items(self, handler):
        for item in self.items:
            handler.startElement(u'item', self.item_attributes(item))
            self.add_item_elements(handler, item)
            handler.endElement(u"item")

    def add_root_elements(self, handler):
        handler.addQuickElement(u"title", self.feed['title'])
        handler.addQuickElement(u"link", self.feed['link'])
        handler.addQuickElement(u"description", self.feed['description'])
        handler.addQuickElement(u"atom:link", None, {u"rel": u"self", u"href": self.feed['feed_url']})
        if self.feed['language'] is not None:
            handler.addQuickElement(u"language", self.feed['language'])
        for cat in self.feed['categories']:
            handler.addQuickElement(u"category", cat)
        if self.feed['feed_copyright'] is not None:
            handler.addQuickElement(u"copyright", self.feed['feed_copyright'])
        handler.addQuickElement(u"lastBuildDate", rfc2822_date(self.latest_post_date()).decode('utf-8'))
        if self.feed['ttl'] is not None:
            handler.addQuickElement(u"ttl", self.feed['ttl'])

    def endChannelElement(self, handler):
        handler.endElement(u"channel")

class RssUserland091Feed(RssFeed):
    _version = u"0.91"
    def add_item_elements(self, handler, item):
        handler.addQuickElement(u"title", item['title'])
        handler.addQuickElement(u"link", item['link'])
        if item['description'] is not None:
            handler.addQuickElement(u"description", item['description'])

class Rss201rev2Feed(RssFeed):
    # Spec: http://blogs.law.harvard.edu/tech/rss
    _version = u"2.0"
    def add_item_elements(self, handler, item):
        handler.addQuickElement(u"title", item['title'])
        handler.addQuickElement(u"link", item['link'])
        if item['description'] is not None:
            handler.addQuickElement(u"description", item['description'])

        # Author information.
        if item["author_name"] and item["author_email"]:
            handler.addQuickElement(u"author", "%s (%s)" % \
                (item['author_email'], item['author_name']))
        elif item["author_email"]:
            handler.addQuickElement(u"author", item["author_email"])
        elif item["author_name"]:
            handler.addQuickElement(u"dc:creator", item["author_name"], {u"xmlns:dc": u"http://purl.org/dc/elements/1.1/"})

        if item['pubdate'] is not None:
            handler.addQuickElement(u"pubDate", rfc2822_date(item['pubdate']).decode('utf-8'))
        if item['comments'] is not None:
            handler.addQuickElement(u"comments", item['comments'])
        if item['unique_id'] is not None:
            handler.addQuickElement(u"guid", item['unique_id'])
        if item['ttl'] is not None:
            handler.addQuickElement(u"ttl", item['ttl'])

        # Enclosure.
        if item['enclosure'] is not None:
            handler.addQuickElement(u"enclosure", '',
                {u"url": item['enclosure'].url, u"length": item['enclosure'].length,
                    u"type": item['enclosure'].mime_type})

        # Categories.
        for cat in item['categories']:
            handler.addQuickElement(u"category", cat)

class Atom1Feed(SyndicationFeed):
    # Spec: http://atompub.org/2005/07/11/draft-ietf-atompub-format-10.html
    mime_type = 'application/atom+xml'
    ns = u"http://www.w3.org/2005/Atom"

    def write(self, outfile, encoding):
        handler = SimplerXMLGenerator(outfile, encoding)
        handler.startDocument()
        handler.startElement(u'feed', self.root_attributes())
        self.add_root_elements(handler)
        self.write_items(handler)
        handler.endElement(u"feed")

    def root_attributes(self):
        if self.feed['language'] is not None:
            return {u"xmlns": self.ns, u"xml:lang": self.feed['language']}
        else:
            return {u"xmlns": self.ns}

    def add_root_elements(self, handler):
        handler.addQuickElement(u"title", self.feed['title'])
        handler.addQuickElement(u"link", "", {u"rel": u"alternate", u"href": self.feed['link']})
        if self.feed['feed_url'] is not None:
            handler.addQuickElement(u"link", "", {u"rel": u"self", u"href": self.feed['feed_url']})
        handler.addQuickElement(u"id", self.feed['id'])
        handler.addQuickElement(u"updated", rfc3339_date(self.latest_post_date()).decode('utf-8'))
        if self.feed['author_name'] is not None:
            handler.startElement(u"author", {})
            handler.addQuickElement(u"name", self.feed['author_name'])
            if self.feed['author_email'] is not None:
                handler.addQuickElement(u"email", self.feed['author_email'])
            if self.feed['author_link'] is not None:
                handler.addQuickElement(u"uri", self.feed['author_link'])
            handler.endElement(u"author")
        if self.feed['subtitle'] is not None:
            handler.addQuickElement(u"subtitle", self.feed['subtitle'])
        for cat in self.feed['categories']:
            handler.addQuickElement(u"category", "", {u"term": cat})
        if self.feed['feed_copyright'] is not None:
            handler.addQuickElement(u"rights", self.feed['feed_copyright'])

    def write_items(self, handler):
        for item in self.items:
            handler.startElement(u"entry", self.item_attributes(item))
            self.add_item_elements(handler, item)
            handler.endElement(u"entry")

    def add_item_elements(self, handler, item):
        handler.addQuickElement(u"title", item['title'])
        handler.addQuickElement(u"link", u"", {u"href": item['link'], u"rel": u"alternate"})
        if item['pubdate'] is not None:
            handler.addQuickElement(u"updated", rfc3339_date(item['pubdate']).decode('utf-8'))

        # Author information.
        if item['author_name'] is not None:
            handler.startElement(u"author", {})
            handler.addQuickElement(u"name", item['author_name'])
            if item['author_email'] is not None:
                handler.addQuickElement(u"email", item['author_email'])
            if item['author_link'] is not None:
                handler.addQuickElement(u"uri", item['author_link'])
            handler.endElement(u"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(u"id", unique_id)

        # Summary.
        if item['description'] is not None:
            handler.addQuickElement(u"summary", item['description'], {u"type": u"html"})

        # Enclosure.
        if item['enclosure'] is not None:
            handler.addQuickElement(u"link", '',
                {u"rel": u"enclosure",
                 u"href": item['enclosure'].url,
                 u"length": item['enclosure'].length,
                 u"type": item['enclosure'].mime_type})

        # Categories.
        for cat in item['categories']:
            handler.addQuickElement(u"category", u"", {u"term": cat})

        # Rights.
        if item['item_copyright'] is not None:
            handler.addQuickElement(u"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
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.