mygpo/core/slugs.py

   1 from itertools import count
   2
   3 from django.utils.text import slugify
   4
   5 from mygpo.podcasts.models import Slug, Episode
   6
   7
   8 # TODO: move to feed-downloader?
   9 def assign_missing_episode_slugs(podcast):
  10     common_title = podcast.get_common_episode_title()
  11
  12     episodes = Episode.objects.filter(podcast=podcast, slugs__isnull=True)
  13
  14     for episode in episodes:
  15         slug = EpisodeSlug(episode, common_title).get_slug()
  16         if slug:
  17             episode.set_slug(slug)
  18
  19
  20 class SlugGenerator(object):
  21     """ Generates a unique slug for an object """
  22
  23
  24     def __init__(self, obj, override_existing=False):
  25         if obj.slug and not override_existing:
  26             raise ValueError('%(obj)s already has slug %(slug)s' % \
  27                 dict(obj=obj, slug=obj.slug))
  28
  29         self.obj = obj
  30         self.base_slug = self._get_base_slug(obj)
  31
  32
  33     @staticmethod
  34     def _get_base_slug(obj):
  35         if not obj.title:
  36             return None
  37         base_slug = slugify(obj.title)
  38         return base_slug
  39
  40
  41     @staticmethod
  42     def _get_existing_slugs():
  43         return []
  44
  45
  46     def get_slug(self):
  47         """ Gets existing slugs and appends numbers until slug is unique """
  48         if not self.base_slug:
  49             return None
  50
  51         existing_slugs = self._get_existing_slugs()
  52
  53         if not self.base_slug in existing_slugs:
  54             return str(self.base_slug)
  55
  56         for n in count(1):
  57             tmp_slug = '%s-%d' % (self.base_slug, n)
  58             if not tmp_slug in existing_slugs:
  59                 # slugify returns SafeUnicode, we need a plain string
  60                 return str(tmp_slug)
  61
  62     def _get_existing_slugs(self):
  63         query = Slug.objects.filter(scope=self.obj.scope,
  64                                     slug__startswith=self.base_slug)
  65         return [s.slug for s in query]
  66
  67
  68 class PodcastGroupSlug(SlugGenerator):
  69     """ Generates slugs for Podcast Groups """
  70
  71     pass
  72
  73
  74 class PodcastSlug(PodcastGroupSlug):
  75     """ Generates slugs for Podcasts """
  76
  77     @staticmethod
  78     def _get_base_slug(podcast):
  79         base_slug = SlugGenerator._get_base_slug(podcast)
  80
  81         if not base_slug:
  82             return None
  83
  84         # append group_member_name to slug
  85         if podcast.group_member_name:
  86             member_slug = slugify(podcast.group_member_name)
  87             if member_slug and not member_slug in base_slug:
  88                 base_slug = '%s-%s' % (base_slug, member_slug)
  89
  90         return base_slug
  91
  92
  93
  94 class EpisodeSlug(SlugGenerator):
  95     """ Generates slugs for Episodes """
  96
  97     def __init__(self, episode, common_title, override_existing=False):
  98         self.common_title = common_title
  99         super(EpisodeSlug, self).__init__(episode, override_existing)
 100         self.podcast_id = episode.podcast
 101
 102
 103     def _get_base_slug(self, obj):
 104
 105         number = obj.get_episode_number(self.common_title)
 106         if number:
 107             return str(number)
 108
 109         short_title = obj.get_short_title(self.common_title)
 110         if short_title:
 111             return slugify(short_title)
 112
 113         if obj.title:
 114             return slugify(obj.title)
 115
 116         return None