root / atomisator / outputs / rss.py

#!/usr/bin/python
# -*- coding: UTF-8 -*-
#
# Copyright (c) 2007 Tarek Ziadé
#
# Authors:
#   Tarek Ziadé <tarek@ziade.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
# $Id: tables.py 1518 2007-05-21 12:35:44Z rage $
""" export to rss
"""
import time
from cgi import escape
import os

from outputing import register_output

module_path, file = os.path.split(__file__)
template = os.path.join(module_path, 'feed.rdf')
RSS_FMT = open(template, 'r').read()

RDF_NS = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"

RSS_ITEM_LI = '<rdf:li rdf:resource="%(item_id)s" />\n'

RSS_ITEM = """\
<item rdf:about="%(item_id)s">
  <title>%(item_title)s</title>
  <description>%(item_description)s</description>
  <link>%(item_link)s</link>
  %(item_dc)s
</item>
"""

RSS_ITEM_DC = '<dc:%(dc_key)s>%(dc_value)s</dc:%(dc_key)s>\n'

def rss(entries):
    """returns a rss feed, given db entries"""
    def _encode_item(item):
        if 'encoding' not in item:
            return item
        encoding = item['encoding']
        for element in item:
            if isinstance(item[element], unicode):
                item[element] = item[element].encode(encoding)
        return item

    base_url = 'http://meta/'
    channel_url = '%sexportrss' % base_url
    channel_description = "Meta Feed"
    header_text = body_text = ''

    entries = [_encode_item(entry) for entry in entries.select_entries()]

    for item in entries:
        if 'link' in item.keys():
            url = escape(item['link'])
        elif 'url' in item.keys():
            url = escape(item['url'])
        else:
            url = 'no link'

        header_text += RSS_ITEM_LI % {'item_id': url}
        if 'modified_parsed' in item.keys():
            item_time = item['modified_parsed']
        else:
            item_time = time.localtime()

        item_date = time.strftime('%c', item_time)
        dc_text = ''
        item_title = escape(item['title'])
        dc_text += '    <dc:subject>%s</dc:subject>\n' % item_title
        strip_html = lambda text: text

        if 'summary' in item.keys():
            summary = strip_html(item['summary'])
        elif 'summary_detail' in item.keys():
            summary = strip_html(item['summary_detail']['value'])
            if len(summary) > DESCRIPTION_MAX_LENGTH:
                summary = summary[:DESCRIPTION_MAX_LENGTH]
                i = summary.rfind(' ')
                if i > 0:
                    summary = summary[:i]
                summary += '...'
        elif 'description' in item.keys():
            summary = item['description']
        elif 'content' in item.keys():
            summary = item['content']
        else:
            summary = '?'

        if 'title' in item.keys():
            title = item['title']
        else:
            title = ''

        current_item = RSS_ITEM % {'item_id': url,
                                   'item_title': escape(title),
                                   'item_description': escape(summary),
                                   'item_link': url,
                                   'item_dc': dc_text}

        body_text += current_item

    text = RSS_FMT % {'css_url': base_url + 'rss.css',
                    'rdf_ns': RDF_NS,
                    'channel_about': channel_url,
                    'channel_title': 'Atomisator',
                    'channel_link': channel_url,
                    'channel_description': escape(channel_description),
                    'items_li': header_text,
                    'items': body_text,
                    'js_url': base_url + 'rss.js',
                    }

    return text

register_output('rss', rss)