def copy_managers(cls, base_managers):
# This is in-place sorting of an Options attribute, but that's fine.
base_managers.sort()
for _, mgr_name, manager in base_managers:
val = getattr(cls, mgr_name, None)
if not val or val is manager:
new_manager = manager._copy_to_model(cls)
cls.add_to_class(mgr_name, new_manager)
def copy_managers(cls, base_managers):
# This is in-place sorting of an Options attribute, but that's fine.
base_managers.sort()
for _, mgr_name, manager in base_managers:
val = getattr(cls, mgr_name, None)
if not val or val is manager:
new_manager = manager._copy_to_model(cls)
cls.add_to_class(mgr_name, new_manager)
def __new__(cls, name, bases, attrs):
super_new = super(ModelBase, cls).__new__
parents = [b for b in bases if isinstance(b, ModelBase)]
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 'django.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('DoesNotExist', ObjectDoesNotExist, module))
new_class.add_to_class(
'MultipleObjectsReturned',
subclass_exception('MultipleObjectsReturned',
MultipleObjectsReturned, module))
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
if getattr(new_class, '_default_manager', None):
new_class._default_manager = None
new_class._base_manager = None
# Bail out early if we have already created this class.
m = get_model(new_class._meta.app_label, name, 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)
# 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:
if not hasattr(base, '_meta'):
# Things without _meta aren't functional models, so they're
# uninteresting parents.
continue
# 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])
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...
if base in o2o_map:
field = o2o_map[base]
else:
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)
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.
base_managers = base._meta.abstract_managers
base_managers.sort()
for _, mgr_name, manager in base_managers:
val = getattr(new_class, mgr_name, None)
if not val or val is manager:
new_manager = manager._copy_to_model(new_class)
new_class.add_to_class(mgr_name, new_manager)
# 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, False)
