utils.py

   1 from django.db import models
   2 from django.contrib.contenttypes.models import ContentType
   3
   4
   5 class ContentTypeLimiter(object):
   6         def q_object(self):
   7                 return models.Q(pk__in=[])
   8
   9         def add_to_query(self, query, *args, **kwargs):
  10                 query.add_q(self.q_object(), *args, **kwargs)
  11
  12
  13 class ContentTypeRegistryLimiter(ContentTypeLimiter):
  14         def __init__(self):
  15                 self.classes = []
  16
  17         def register_class(self, cls):
  18                 self.classes.append(cls)
  19
  20         def unregister_class(self, cls):
  21                 self.classes.remove(cls)
  22
  23         def q_object(self):
  24                 contenttype_pks = []
  25                 for cls in self.classes:
  26                         try:
  27                                 if issubclass(cls, models.Model):
  28                                         if not cls._meta.abstract:
  29                                                 contenttype = ContentType.objects.get_for_model(cls)
  30                                                 contenttype_pks.append(contenttype.pk)
  31                         except:
  32                                 pass
  33                 return models.Q(pk__in=contenttype_pks)
  34
  35
  36 class ContentTypeSubclassLimiter(ContentTypeLimiter):
  37         def __init__(self, cls, inclusive=False):
  38                 self.cls = cls
  39                 self.inclusive = inclusive
  40
  41         def q_object(self):
  42                 contenttype_pks = []
  43                 def handle_subclasses(cls):
  44                         for subclass in cls.__subclasses__():
  45                                 try:
  46                                         if issubclass(subclass, models.Model):
  47                                                 if not subclass._meta.abstract:
  48                                                         if not self.inclusive and subclass is self.cls:
  49                                                                 continue
  50                                                         contenttype = ContentType.objects.get_for_model(subclass)
  51                                                         contenttype_pks.append(contenttype.pk)
  52                                         handle_subclasses(subclass)
  53                                 except:
  54                                         pass
  55                 handle_subclasses(self.cls)
  56                 return models.Q(pk__in=contenttype_pks)
  57
  58
  59 def fattr(*args, **kwargs):
  60         def wrapper(function):
  61                 for key in kwargs:
  62                         setattr(function, key, kwargs[key])
  63                 return function
  64         return wrapper