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Commit 4b606c75 by Nicholas Serra
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manager default to _TaggableManager in kwarg, swap class placement for import.

parent e9b9de1b
Showing with 146 additions and 146 deletions
taggit/managers.py
......@@ -69,16 +69,160 @@ class ExtraJoinRestriction(object):
return self.__class__(self.alias, self.col, self.content_types[:])
class _TaggableManager(models.Manager):
def __init__(self, through, model, instance, prefetch_cache_name):
self.through = through
self.model = model
self.instance = instance
self.prefetch_cache_name = prefetch_cache_name
self._db = None
def is_cached(self, instance):
return self.prefetch_cache_name in instance._prefetched_objects_cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
except (AttributeError, KeyError):
return self.through.tags_for(self.model, self.instance)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is not None:
raise ValueError("Custom queryset can't be used for this lookup.")
instance = instances[0]
from django.db import connections
db = self._db or router.db_for_read(instance.__class__, instance=instance)
fieldname = ('object_id' if issubclass(self.through, GenericTaggedItemBase)
else 'content_object')
fk = self.through._meta.get_field(fieldname)
query = {
'%s__%s__in' % (self.through.tag_relname(), fk.name) :
set(obj._get_pk_val() for obj in instances)
}
join_table = self.through._meta.db_table
source_col = fk.column
connection = connections[db]
qn = connection.ops.quote_name
qs = self.get_queryset().using(db)._next_is_sticky().filter(**query).extra(
select = {
'_prefetch_related_val' : '%s.%s' % (qn(join_table), qn(source_col))
}
)
return (qs,
attrgetter('_prefetch_related_val'),
attrgetter(instance._meta.pk.name),
False,
self.prefetch_cache_name)
# Django < 1.6 uses the previous name of query_set
get_query_set = get_queryset
get_prefetch_query_set = get_prefetch_queryset
def _lookup_kwargs(self):
return self.through.lookup_kwargs(self.instance)
@require_instance_manager
def add(self, *tags):
str_tags = set([
t
for t in tags
if not isinstance(t, self.through.tag_model())
])
tag_objs = set(tags) - str_tags
# If str_tags has 0 elements Django actually optimizes that to not do a
# query. Malcolm is very smart.
existing = self.through.tag_model().objects.filter(
name__in=str_tags
)
tag_objs.update(existing)
for new_tag in str_tags - set(t.name for t in existing):
tag_objs.add(self.through.tag_model().objects.create(name=new_tag))
for tag in tag_objs:
self.through.objects.get_or_create(tag=tag, **self._lookup_kwargs())
@require_instance_manager
def names(self):
return self.get_queryset().values_list('name', flat=True)
@require_instance_manager
def slugs(self):
return self.get_queryset().values_list('slug', flat=True)
@require_instance_manager
def set(self, *tags):
self.clear()
self.add(*tags)
@require_instance_manager
def remove(self, *tags):
self.through.objects.filter(**self._lookup_kwargs()).filter(
tag__name__in=tags).delete()
@require_instance_manager
def clear(self):
self.through.objects.filter(**self._lookup_kwargs()).delete()
def most_common(self):
return self.get_queryset().annotate(
num_times=models.Count(self.through.tag_relname())
).order_by('-num_times')
@require_instance_manager
def similar_objects(self):
lookup_kwargs = self._lookup_kwargs()
lookup_keys = sorted(lookup_kwargs)
qs = self.through.objects.values(*six.iterkeys(lookup_kwargs))
qs = qs.annotate(n=models.Count('pk'))
qs = qs.exclude(**lookup_kwargs)
qs = qs.filter(tag__in=self.all())
qs = qs.order_by('-n')
# TODO: This all feels like a bit of a hack.
items = {}
if len(lookup_keys) == 1:
# Can we do this without a second query by using a select_related()
# somehow?
f = self.through._meta.get_field_by_name(lookup_keys[0])[0]
objs = f.rel.to._default_manager.filter(**{
"%s__in" % f.rel.field_name: [r["content_object"] for r in qs]
})
for obj in objs:
items[(getattr(obj, f.rel.field_name),)] = obj
else:
preload = {}
for result in qs:
preload.setdefault(result['content_type'], set())
preload[result["content_type"]].add(result["object_id"])
for ct, obj_ids in preload.items():
ct = ContentType.objects.get_for_id(ct)
for obj in ct.model_class()._default_manager.filter(pk__in=obj_ids):
items[(ct.pk, obj.pk)] = obj
results = []
for result in qs:
obj = items[
tuple(result[k] for k in lookup_keys)
]
obj.similar_tags = result["n"]
results.append(obj)
return results
class TaggableManager(RelatedField, Field):
_related_name_counter = 0
def __init__(self, verbose_name=_("Tags"), help_text=_("A comma-separated list of tags."),
through=None, blank=False, related_name=None, manager=None):
through=None, blank=False, related_name=None, manager=_TaggableManager):
Field.__init__(self, verbose_name=verbose_name, help_text=help_text, blank=blank, null=True, serialize=False)
self.through = through or TaggedItem
self.rel = TaggableRel(self, related_name, self.through)
self.swappable = False
self.manager = manager or _TaggableManager
self.manager = manager
def __get__(self, instance, model):
if instance is not None and instance.pk is None:
......@@ -286,150 +430,6 @@ class TaggableManager(RelatedField, Field):
return [self.related_fields[0][1]]
class _TaggableManager(models.Manager):
def __init__(self, through, model, instance, prefetch_cache_name):
self.through = through
self.model = model
self.instance = instance
self.prefetch_cache_name = prefetch_cache_name
self._db = None
def is_cached(self, instance):
return self.prefetch_cache_name in instance._prefetched_objects_cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
except (AttributeError, KeyError):
return self.through.tags_for(self.model, self.instance)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is not None:
raise ValueError("Custom queryset can't be used for this lookup.")
instance = instances[0]
from django.db import connections
db = self._db or router.db_for_read(instance.__class__, instance=instance)
fieldname = ('object_id' if issubclass(self.through, GenericTaggedItemBase)
else 'content_object')
fk = self.through._meta.get_field(fieldname)
query = {
'%s__%s__in' % (self.through.tag_relname(), fk.name) :
set(obj._get_pk_val() for obj in instances)
}
join_table = self.through._meta.db_table
source_col = fk.column
connection = connections[db]
qn = connection.ops.quote_name
qs = self.get_queryset().using(db)._next_is_sticky().filter(**query).extra(
select = {
'_prefetch_related_val' : '%s.%s' % (qn(join_table), qn(source_col))
}
)
return (qs,
attrgetter('_prefetch_related_val'),
attrgetter(instance._meta.pk.name),
False,
self.prefetch_cache_name)
# Django < 1.6 uses the previous name of query_set
get_query_set = get_queryset
get_prefetch_query_set = get_prefetch_queryset
def _lookup_kwargs(self):
return self.through.lookup_kwargs(self.instance)
@require_instance_manager
def add(self, *tags):
str_tags = set([
t
for t in tags
if not isinstance(t, self.through.tag_model())
])
tag_objs = set(tags) - str_tags
# If str_tags has 0 elements Django actually optimizes that to not do a
# query. Malcolm is very smart.
existing = self.through.tag_model().objects.filter(
name__in=str_tags
)
tag_objs.update(existing)
for new_tag in str_tags - set(t.name for t in existing):
tag_objs.add(self.through.tag_model().objects.create(name=new_tag))
for tag in tag_objs:
self.through.objects.get_or_create(tag=tag, **self._lookup_kwargs())
@require_instance_manager
def names(self):
return self.get_queryset().values_list('name', flat=True)
@require_instance_manager
def slugs(self):
return self.get_queryset().values_list('slug', flat=True)
@require_instance_manager
def set(self, *tags):
self.clear()
self.add(*tags)
@require_instance_manager
def remove(self, *tags):
self.through.objects.filter(**self._lookup_kwargs()).filter(
tag__name__in=tags).delete()
@require_instance_manager
def clear(self):
self.through.objects.filter(**self._lookup_kwargs()).delete()
def most_common(self):
return self.get_queryset().annotate(
num_times=models.Count(self.through.tag_relname())
).order_by('-num_times')
@require_instance_manager
def similar_objects(self):
lookup_kwargs = self._lookup_kwargs()
lookup_keys = sorted(lookup_kwargs)
qs = self.through.objects.values(*six.iterkeys(lookup_kwargs))
qs = qs.annotate(n=models.Count('pk'))
qs = qs.exclude(**lookup_kwargs)
qs = qs.filter(tag__in=self.all())
qs = qs.order_by('-n')
# TODO: This all feels like a bit of a hack.
items = {}
if len(lookup_keys) == 1:
# Can we do this without a second query by using a select_related()
# somehow?
f = self.through._meta.get_field_by_name(lookup_keys[0])[0]
objs = f.rel.to._default_manager.filter(**{
"%s__in" % f.rel.field_name: [r["content_object"] for r in qs]
})
for obj in objs:
items[(getattr(obj, f.rel.field_name),)] = obj
else:
preload = {}
for result in qs:
preload.setdefault(result['content_type'], set())
preload[result["content_type"]].add(result["object_id"])
for ct, obj_ids in preload.items():
ct = ContentType.objects.get_for_id(ct)
for obj in ct.model_class()._default_manager.filter(pk__in=obj_ids):
items[(ct.pk, obj.pk)] = obj
results = []
for result in qs:
obj = items[
tuple(result[k] for k in lookup_keys)
]
obj.similar_tags = result["n"]
results.append(obj)
return results
def _get_subclasses(model):
subclasses = [model]
for f in model._meta.get_all_field_names():
......
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