mygpo/core/slugs.py

   1 from collections import defaultdict
   2
   3 from itertools import count
   4
   5 from couchdbkit.ext.django.schema import *
   6
   7 from django.utils.text import slugify
   8
   9 from mygpo.podcasts.models import Slug, Episode
  10 from mygpo.decorators import repeat_on_conflict
  11 from mygpo.utils import partition
  12
  13
  14 # TODO: move to feed-downloader?
  15 def assign_missing_episode_slugs(podcast):
  16     common_title = podcast.get_common_episode_title()
  17
  18     episodes = Episode.objects.filter(podcast=podcast, slugs__isnull=True)
  19
  20     for episode in episodes:
  21         slug = EpisodeSlug(episode, common_title).get_slug()
  22         if slug:
  23             episode.set_slug(slug)
  24
  25
  26 class SlugGenerator(object):
  27     """ Generates a unique slug for an object """
  28
  29
  30     def __init__(self, obj, override_existing=False):
  31         if obj.slug and not override_existing:
  32             raise ValueError('%(obj)s already has slug %(slug)s' % \
  33                 dict(obj=obj, slug=obj.slug))
  34
  35         self.obj = obj
  36         self.base_slug = self._get_base_slug(obj)
  37
  38
  39     @staticmethod
  40     def _get_base_slug(obj):
  41         if not obj.title:
  42             return None
  43         base_slug = slugify(obj.title)
  44         return base_slug
  45
  46
  47     @staticmethod
  48     def _get_existing_slugs():
  49         return []
  50
  51
  52     def get_slug(self):
  53         """ Gets existing slugs and appends numbers until slug is unique """
  54         if not self.base_slug:
  55             return None
  56
  57         existing_slugs = self._get_existing_slugs()
  58
  59         if not self.base_slug in existing_slugs:
  60             return str(self.base_slug)
  61
  62         for n in count(1):
  63             tmp_slug = '%s-%d' % (self.base_slug, n)
  64             if not tmp_slug in existing_slugs:
  65                 # slugify returns SafeUnicode, we need a plain string
  66                 return str(tmp_slug)
  67
  68     def _get_existing_slugs(self):
  69         query = Slug.objects.filter(scope=self.obj.scope,
  70                                     slug__startswith=self.base_slug)
  71         return [s.slug for s in query]
  72
  73
  74 class PodcastGroupSlug(SlugGenerator):
  75     """ Generates slugs for Podcast Groups """
  76
  77     pass
  78
  79
  80 class PodcastSlug(PodcastGroupSlug):
  81     """ Generates slugs for Podcasts """
  82
  83     @staticmethod
  84     def _get_base_slug(podcast):
  85         base_slug = SlugGenerator._get_base_slug(podcast)
  86
  87         if not base_slug:
  88             return None
  89
  90         # append group_member_name to slug
  91         if podcast.group_member_name:
  92             member_slug = slugify(podcast.group_member_name)
  93             if member_slug and not member_slug in base_slug:
  94                 base_slug = '%s-%s' % (base_slug, member_slug)
  95
  96         return base_slug
  97
  98
  99
 100 class EpisodeSlug(SlugGenerator):
 101     """ Generates slugs for Episodes """
 102
 103     def __init__(self, episode, common_title, override_existing=False):
 104         self.common_title = common_title
 105         super(EpisodeSlug, self).__init__(episode, override_existing)
 106         self.podcast_id = episode.podcast
 107
 108
 109     def _get_base_slug(self, obj):
 110
 111         number = obj.get_episode_number(self.common_title)
 112         if number:
 113             return str(number)
 114
 115         short_title = obj.get_short_title(self.common_title)
 116         if short_title:
 117             return slugify(short_title)
 118
 119         if obj.title:
 120             return slugify(obj.title)
 121
 122         return None
 123
 124
 125 class SlugMixin(DocumentSchema):
 126     slug         = StringProperty()
 127     merged_slugs = StringListProperty()
 128
 129     def set_slug(self, slug):
 130         """ Set the main slug of the object """
 131
 132         if self.slug:
 133             self.merged_slugs.append(self.slug)
 134
 135         self.merged_slugs = list(set(self.merged_slugs) - set([slug]))
 136
 137         self.slug = slug
 138
 139
 140     def remove_slug(self, slug):
 141         """ Removes the slug from the object """
 142
 143         # remove main slug
 144         if self.slug == slug:
 145             self.slug = None
 146
 147         # remove from merged slugs
 148         self.merged_slugs = list(set(self.merged_slugs) - set([slug]))