mygpo/core/slugs.py

   1 from itertools import count
   2
   3 from django.utils.text import slugify
   4
   5
   6 class SlugGenerator(object):
   7     """ Generates a unique slug for an object """
   8
   9     def __init__(self, obj):
  10         if obj.slug:
  11             raise ValueError('%(obj)s already has slug %(slug)s' %
  12                              dict(obj=obj, slug=obj.slug))
  13
  14         self.obj = obj
  15         self.base_slug = self._get_base_slug(obj)
  16
  17     @staticmethod
  18     def _get_base_slug(obj):
  19         if not obj.title:
  20             return None
  21         base_slug = slugify(obj.title)
  22         return base_slug
  23
  24     def __iter__(self):
  25         """ Generates possible slugs
  26
  27         The consumer can can consume until it get's an unused one """
  28
  29         if not self.base_slug:
  30             raise StopIteration
  31
  32         # first we try with the base slug
  33         yield str(self.base_slug)
  34
  35         for n in count(1):
  36             tmp_slug = '%s-%d' % (self.base_slug, n)
  37             # slugify returns SafeUnicode, we need a plain string
  38             yield str(tmp_slug)
  39
  40
  41 class PodcastGroupSlugs(SlugGenerator):
  42     """ Generates slugs for Podcast Groups """
  43     pass
  44
  45
  46 class PodcastSlugs(PodcastGroupSlugs):
  47     """ Generates slugs for Podcasts """
  48
  49     def _get_base_slug(self, podcast):
  50         base_slug = SlugGenerator._get_base_slug(podcast)
  51
  52         if not base_slug:
  53             return None
  54
  55         # append group_member_name to slug
  56         if podcast.group_member_name:
  57             member_slug = slugify(podcast.group_member_name)
  58             if member_slug and not member_slug in base_slug:
  59                 base_slug = '%s-%s' % (base_slug, member_slug)
  60
  61         return base_slug
  62
  63
  64 class EpisodeSlugs(SlugGenerator):
  65     """ Generates slugs for Episodes """
  66
  67     def __init__(self, episode, common_title):
  68         self.common_title = common_title
  69         super().__init__(episode)
  70
  71     def _get_base_slug(self, obj):
  72         number = obj.get_episode_number(self.common_title)
  73         if number:
  74             return str(number)
  75
  76         short_title = obj.get_short_title(self.common_title)
  77         if short_title:
  78             return slugify(short_title)
  79
  80         if obj.title:
  81             return slugify(obj.title)
  82
  83         return None