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
  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, slug__isnull=True)
  19
  20     for episode in episodes:
  21         slug = EpisodeSlug(episode, common_title).get_slug()
  22         episode.set_slug(slug)
  23
  24
  25 class SlugGenerator(object):
  26     """ Generates a unique slug for an object """
  27
  28
  29     def __init__(self, obj, override_existing=False):
  30         if obj.slug and not override_existing:
  31             raise ValueError('%(obj)s already has slug %(slug)s' % \
  32                 dict(obj=obj, slug=obj.slug))
  33
  34         self.base_slug = self._get_base_slug(obj)
  35
  36
  37     @staticmethod
  38     def _get_base_slug(obj):
  39         if not obj.title:
  40             return None
  41         base_slug = slugify(obj.title)
  42         return base_slug
  43
  44
  45     @staticmethod
  46     def _get_existing_slugs():
  47         return []
  48
  49
  50     def get_slug(self):
  51         """ Gets existing slugs and appends numbers until slug is unique """
  52         if not self.base_slug:
  53             return None
  54
  55         existing_slugs = self._get_existing_slugs()
  56
  57         if not self.base_slug in existing_slugs:
  58             return str(self.base_slug)
  59
  60         for n in count(1):
  61             tmp_slug = '%s-%d' % (self.base_slug, n)
  62             if not tmp_slug in existing_slugs:
  63                 # slugify returns SafeUnicode, we need a plain string
  64                 return str(tmp_slug)
  65
  66
  67
  68 class PodcastGroupSlug(SlugGenerator):
  69     """ Generates slugs for Podcast Groups """
  70
  71     def _get_existing_slugs(self):
  72         query = Slug.objects.filter(scope__isnull=True,
  73                                     slug__startswith=self.base_slug)
  74         return [s['slug'] for s in query]
  75
  76
  77
  78 class PodcastSlug(PodcastGroupSlug):
  79     """ Generates slugs for Podcasts """
  80
  81     @staticmethod
  82     def _get_base_slug(podcast):
  83         base_slug = SlugGenerator._get_base_slug(podcast)
  84
  85         if not base_slug:
  86             return None
  87
  88         # append group_member_name to slug
  89         if podcast.group_member_name:
  90             member_slug = slugify(podcast.group_member_name)
  91             if member_slug and not member_slug in base_slug:
  92                 base_slug = '%s-%s' % (base_slug, member_slug)
  93
  94         return base_slug
  95
  96
  97
  98 class EpisodeSlug(SlugGenerator):
  99     """ Generates slugs for Episodes """
 100
 101     def __init__(self, episode, common_title, override_existing=False):
 102         self.common_title = common_title
 103         super(EpisodeSlug, self).__init__(episode, override_existing)
 104         self.podcast_id = episode.podcast
 105
 106
 107     def _get_base_slug(self, obj):
 108
 109         number = obj.get_episode_number(self.common_title)
 110         if number:
 111             return str(number)
 112
 113         short_title = obj.get_short_title(self.common_title)
 114         if short_title:
 115             return slugify(short_title)
 116
 117         if obj.title:
 118             return slugify(obj.title)
 119
 120         return None
 121
 122
 123     def _get_existing_slugs(self):
 124         """ Episode slugs have to be unique within the Podcast """
 125         query = Slug.objects.filter(scope=self.podcast_id,
 126                                     slug__startswith=self.base_slug)
 127         return [s['slug'] for s in query]
 128
 129
 130 class SlugMixin(DocumentSchema):
 131     slug         = StringProperty()
 132     merged_slugs = StringListProperty()
 133
 134     def set_slug(self, slug):
 135         """ Set the main slug of the object """
 136
 137         if self.slug:
 138             self.merged_slugs.append(self.slug)
 139
 140         self.merged_slugs = list(set(self.merged_slugs) - set([slug]))
 141
 142         self.slug = slug
 143
 144
 145     def remove_slug(self, slug):
 146         """ Removes the slug from the object """
 147
 148         # remove main slug
 149         if self.slug == slug:
 150             self.slug = None
 151
 152         # remove from merged slugs
 153         self.merged_slugs = list(set(self.merged_slugs) - set([slug]))