def get_content_type(self, obj=None, id=None, using=None):
# Convenience function using get_model avoids a circular import when
# using this model
ContentType = get_model("contenttypes", "contenttype")
if obj:
return ContentType.objects.db_manager(obj._state.db).get_for_model(obj)
elif id:
return ContentType.objects.db_manager(using).get_for_id(id)
else:
# This should never happen. I love comments like this, don't you?
raise Exception("Impossible arguments to GFK.get_content_type!")
def extra_filters(self, pieces, pos, negate):
"""
Return an extra filter to the queryset so that the results are filtered
on the appropriate content type.
"""
if negate:
return []
ContentType = get_model("contenttypes", "contenttype")
content_type = ContentType.objects.get_for_model(self.model)
prefix = "__".join(pieces[:pos + 1])
return [("%s__%s" % (prefix, self.content_type_field_name),
content_type)]
def test_get_model_only_returns_installed_models(self):
self.assertEqual(
get_model("not_installed", "NotInstalledModel"), None)
def test_get_model_with_not_installed(self):
self.assertEqual(
get_model(
"not_installed", "NotInstalledModel", only_installed=False),
self.not_installed_module.NotInstalledModel)
def __new__(cls, name, bases, attrs):
super_new = super(ModelBase, cls).__new__
# six.with_metaclass() inserts an extra class called 'NewBase' in the
# inheritance tree: Model -> NewBase -> object. Ignore this class.
parents = [
b for b in bases if isinstance(b, ModelBase) and not (b.__name__ == "NewBase" and b.__mro__ == (b, object))
]
if not parents:
# If this isn't a subclass of Model, don't do anything special.
return super_new(cls, name, bases, attrs)
# Create the class.
module = attrs.pop("__module__")
new_class = super_new(cls, name, bases, {"__module__": module})
attr_meta = attrs.pop("Meta", None)
abstract = getattr(attr_meta, "abstract", False)
if not attr_meta:
meta = getattr(new_class, "Meta", None)
else:
meta = attr_meta
base_meta = getattr(new_class, "_meta", None)
if getattr(meta, "app_label", None) is None:
# Figure out the app_label by looking one level up.
# For 'djangocg.contrib.sites.models', this would be 'sites'.
model_module = sys.modules[new_class.__module__]
kwargs = {"app_label": model_module.__name__.split(".")[-2]}
else:
kwargs = {}
new_class.add_to_class("_meta", Options(meta, **kwargs))
if not abstract:
new_class.add_to_class(
"DoesNotExist",
subclass_exception(
str("DoesNotExist"),
tuple(x.DoesNotExist for x in parents if hasattr(x, "_meta") and not x._meta.abstract)
or (ObjectDoesNotExist,),
module,
attached_to=new_class,
),
)
new_class.add_to_class(
"MultipleObjectsReturned",
subclass_exception(
str("MultipleObjectsReturned"),
tuple(x.MultipleObjectsReturned for x in parents if hasattr(x, "_meta") and not x._meta.abstract)
or (MultipleObjectsReturned,),
module,
attached_to=new_class,
),
)
if base_meta and not base_meta.abstract:
# Non-abstract child classes inherit some attributes from their
# non-abstract parent (unless an ABC comes before it in the
# method resolution order).
if not hasattr(meta, "ordering"):
new_class._meta.ordering = base_meta.ordering
if not hasattr(meta, "get_latest_by"):
new_class._meta.get_latest_by = base_meta.get_latest_by
is_proxy = new_class._meta.proxy
if getattr(new_class, "_default_manager", None):
if not is_proxy:
# Multi-table inheritance doesn't inherit default manager from
# parents.
new_class._default_manager = None
new_class._base_manager = None
else:
# Proxy classes do inherit parent's default manager, if none is
# set explicitly.
new_class._default_manager = new_class._default_manager._copy_to_model(new_class)
new_class._base_manager = new_class._base_manager._copy_to_model(new_class)
# Bail out early if we have already created this class.
m = get_model(new_class._meta.app_label, name, seed_cache=False, only_installed=False)
if m is not None:
return m
# Add all attributes to the class.
for obj_name, obj in attrs.items():
new_class.add_to_class(obj_name, obj)
# All the fields of any type declared on this model
new_fields = new_class._meta.local_fields + new_class._meta.local_many_to_many + new_class._meta.virtual_fields
field_names = set([f.name for f in new_fields])
# Basic setup for proxy models.
if is_proxy:
base = None
for parent in [cls for cls in parents if hasattr(cls, "_meta")]:
if parent._meta.abstract:
if parent._meta.fields:
raise TypeError(
"Abstract base class containing model fields not permitted for proxy model '%s'." % name
)
else:
continue
if base is not None:
raise TypeError("Proxy model '%s' has more than one non-abstract model base class." % name)
else:
base = parent
if base is None:
raise TypeError("Proxy model '%s' has no non-abstract model base class." % name)
if new_class._meta.local_fields or new_class._meta.local_many_to_many:
raise FieldError("Proxy model '%s' contains model fields." % name)
new_class._meta.setup_proxy(base)
new_class._meta.concrete_model = base._meta.concrete_model
else:
new_class._meta.concrete_model = new_class
# Do the appropriate setup for any model parents.
o2o_map = dict([(f.rel.to, f) for f in new_class._meta.local_fields if isinstance(f, OneToOneField)])
for base in parents:
original_base = base
if not hasattr(base, "_meta"):
# Things without _meta aren't functional models, so they're
# uninteresting parents.
continue
parent_fields = base._meta.local_fields + base._meta.local_many_to_many
# Check for clashes between locally declared fields and those
# on the base classes (we cannot handle shadowed fields at the
# moment).
for field in parent_fields:
if field.name in field_names:
raise FieldError(
"Local field %r in class %r clashes "
"with field of similar name from "
"base class %r" % (field.name, name, base.__name__)
)
if not base._meta.abstract:
# Concrete classes...
base = base._meta.concrete_model
if base in o2o_map:
field = o2o_map[base]
elif not is_proxy:
attr_name = "%s_ptr" % base._meta.module_name
field = OneToOneField(base, name=attr_name, auto_created=True, parent_link=True)
new_class.add_to_class(attr_name, field)
else:
field = None
new_class._meta.parents[base] = field
else:
# .. and abstract ones.
for field in parent_fields:
new_class.add_to_class(field.name, copy.deepcopy(field))
# Pass any non-abstract parent classes onto child.
new_class._meta.parents.update(base._meta.parents)
# Inherit managers from the abstract base classes.
new_class.copy_managers(base._meta.abstract_managers)
# Proxy models inherit the non-abstract managers from their base,
# unless they have redefined any of them.
if is_proxy:
new_class.copy_managers(original_base._meta.concrete_managers)
# Inherit virtual fields (like GenericForeignKey) from the parent
# class
for field in base._meta.virtual_fields:
if base._meta.abstract and field.name in field_names:
raise FieldError(
"Local field %r in class %r clashes "
"with field of similar name from "
"abstract base class %r" % (field.name, name, base.__name__)
)
new_class.add_to_class(field.name, copy.deepcopy(field))
if abstract:
# Abstract base models can't be instantiated and don't appear in
# the list of models for an app. We do the final setup for them a
# little differently from normal models.
attr_meta.abstract = False
new_class.Meta = attr_meta
return new_class
new_class._prepare()
register_models(new_class._meta.app_label, new_class)
# Because of the way imports happen (recursively), we may or may not be
# the first time this model tries to register with the framework. There
# should only be one class for each model, so we always return the
# registered version.
return get_model(new_class._meta.app_label, name, seed_cache=False, only_installed=False)
