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 import os.path
  27
  28 import xml.dom.minidom
  29 import email.Utils
  30
  31
  32 class Importer(object):
  33     VALID_TYPES = ('rss', 'link')
  34
  35     def __init__(self, content):
  36         """
  37         Parses the OPML feed from the given URL into a local data structure
  38         containing podcast metadata.
  39         """
  40         self.items = []
  41         try:
  42             doc = xml.dom.minidom.parseString(content)
  43
  44             for outline in doc.getElementsByTagName('outline'):
  45                 if outline.getAttribute('type') in self.VALID_TYPES and \
  46                         outline.getAttribute('xmlUrl') or \
  47                         outline.getAttribute('url'):
  48                     channel = {
  49                         'url': outline.getAttribute('xmlUrl') or \
  50                                outline.getAttribute('url'),
  51                         'title': outline.getAttribute('title') or \
  52                                  outline.getAttribute('text') or \
  53                                  outline.getAttribute('xmlUrl') or \
  54                                  outline.getAttribute('url'),
  55                         'description': outline.getAttribute('text') or \
  56                                        outline.getAttribute('xmlUrl') or \
  57                                        outline.getAttribute('url'),
  58                     }
  59
  60                     if channel['description'] == channel['title']:
  61                         channel['description'] = channel['url']
  62
  63                     for attr in ('url', 'title', 'description'):
  64                         channel[attr] = channel[attr].strip()
  65
  66                     self.items.append(channel)
  67         except Exception, e:
  68             # FIXME: Logging or raising the exception to the caller
  69             print 'OPML read error:', e
  70
  71
  72 class Exporter(object):
  73     """
  74     Helper class to export a list of channel objects to a local file in OPML
  75     1.1 format. See www.opml.org for the OPML specification.
  76     """
  77
  78     def __init__(self, title='my.gpodder.org Subscriptions'):
  79         self.title = title
  80         self.created = email.Utils.formatdate(localtime=True)
  81
  82     def generate(self, channels):
  83         """
  84         Creates a XML document containing metadata for each channel object in
  85         the "channels" parameter, which should be a list of channel objects.
  86
  87         Returns: An OPML document as string
  88         """
  89         doc = xml.dom.minidom.Document()
  90
  91         opml = doc.createElement('opml')
  92         opml.setAttribute('version', '2.0')
  93         doc.appendChild(opml)
  94
  95         def create_node(name, content):
  96             node = doc.createElement(name)
  97             node.appendChild(doc.createTextNode(content))
  98             return node
  99
 100         head = doc.createElement('head')
 101         head.appendChild(create_node('title', self.title))
 102         head.appendChild(create_node('dateCreated', self.created))
 103         opml.appendChild(head)
 104
 105         def create_outline(channel):
 106             outline = doc.createElement('outline')
 107             outline.setAttribute('title', channel.title)
 108             outline.setAttribute('text', channel.description or '')
 109             outline.setAttribute('xmlUrl', channel.url)
 110             outline.setAttribute('type', 'rss')
 111             return outline
 112
 113         body = doc.createElement('body')
 114         for channel in channels:
 115             body.appendChild(create_outline(channel))
 116         opml.appendChild(body)
 117
 118         return doc.toprettyxml(encoding='utf-8', \
 119                                indent='  ', \
 120                                newl=os.linesep)
 121