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