mygpo/api/opml.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # This file is part of my.gpodder.org.
   4 #
   5 # my.gpodder.org is free software: you can redistribute it and/or modify it
   6 # under the terms of the GNU Affero General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or (at your
   8 # option) any later version.
   9 #
  10 # my.gpodder.org is distributed in the hope that it will be useful, but
  11 # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12 # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
  13 # License for more details.
  14 #
  15 # You should have received a copy of the GNU Affero General Public License
  16 # along with my.gpodder.org. If not, see <http://www.gnu.org/licenses/>.
  17 #
  18
  19 """OPML importer and exporter (based on gPodder's "opml" module)
  20
  21 This module contains helper classes to import subscriptions from OPML files on
  22 the web and to export a list of podcast objects to valid OPML 1.1 files.
  23 """
  24
  25 import os
  26
  27 import xml.dom.minidom
  28 import email.Utils
  29
  30
  31 class Importer(object):
  32     VALID_TYPES = ('rss', 'link')
  33
  34     def __init__(self, content):
  35         """
  36         Parses the OPML feed from the given URL into a local data structure
  37         containing podcast metadata.
  38         """
  39         self.items = []
  40         try:
  41             doc = xml.dom.minidom.parseString(content)
  42
  43             for outline in doc.getElementsByTagName('outline'):
  44                 if outline.getAttribute('type') in self.VALID_TYPES and \
  45                         outline.getAttribute('xmlUrl') or \
  46                         outline.getAttribute('url'):
  47                     channel = {
  48                         'url': outline.getAttribute('xmlUrl') or \
  49                                outline.getAttribute('url'),
  50                         'title': outline.getAttribute('title') or \
  51                                  outline.getAttribute('text') or \
  52                                  outline.getAttribute('xmlUrl') or \
  53                                  outline.getAttribute('url'),
  54                         'description': outline.getAttribute('text') or \
  55                                        outline.getAttribute('xmlUrl') or \
  56                                        outline.getAttribute('url'),
  57                     }
  58
  59                     if channel['description'] == channel['title']:
  60                         channel['description'] = channel['url']
  61
  62                     for attr in ('url', 'title', 'description'):
  63                         channel[attr] = channel[attr].strip()
  64
  65                     self.items.append(channel)
  66         except Exception, e:
  67             # FIXME: Logging or raising the exception to the caller
  68             print 'OPML read error:', e
  69
  70
  71 class Exporter(object):
  72     """
  73     Helper class to export a list of channel objects to a local file in OPML
  74     1.1 format. See www.opml.org for the OPML specification.
  75     """
  76
  77     def __init__(self, title='my.gpodder.org Subscriptions'):
  78         self.title = title
  79         self.created = email.Utils.formatdate(localtime=True)
  80
  81     def generate(self, channels):
  82         """
  83         Creates a XML document containing metadata for each channel object in
  84         the "channels" parameter, which should be a list of channel objects.
  85
  86         Returns: An OPML document as string
  87         """
  88         doc = xml.dom.minidom.Document()
  89
  90         opml = doc.createElement('opml')
  91         opml.setAttribute('version', '2.0')
  92         doc.appendChild(opml)
  93
  94         def create_node(name, content):
  95             node = doc.createElement(name)
  96             node.appendChild(doc.createTextNode(content))
  97             return node
  98
  99         head = doc.createElement('head')
 100         head.appendChild(create_node('title', self.title))
 101         head.appendChild(create_node('dateCreated', self.created))
 102         opml.appendChild(head)
 103
 104         def create_outline(channel):
 105             outline = doc.createElement('outline')
 106             outline.setAttribute('title', channel.title)
 107             outline.setAttribute('text', channel.description or '')
 108             outline.setAttribute('xmlUrl', channel.url)
 109             outline.setAttribute('type', 'rss')
 110             return outline
 111
 112         body = doc.createElement('body')
 113         for channel in channels:
 114             body.appendChild(create_outline(channel))
 115         opml.appendChild(body)
 116
 117         return doc.toprettyxml(encoding='utf-8', \
 118                                indent='  ', \
 119                                newl=os.linesep)
 120