1757 lines
70 KiB
Python
1757 lines
70 KiB
Python
![]() |
import copy
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import inspect
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import warnings
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from functools import partialmethod
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from itertools import chain
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from django.apps import apps
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from django.conf import settings
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from django.core import checks
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from django.core.exceptions import (
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NON_FIELD_ERRORS, FieldDoesNotExist, FieldError, MultipleObjectsReturned,
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ObjectDoesNotExist, ValidationError,
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)
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from django.db import (
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DEFAULT_DB_ALIAS, DJANGO_VERSION_PICKLE_KEY, DatabaseError, connection,
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connections, router, transaction,
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)
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from django.db.models.constants import LOOKUP_SEP
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from django.db.models.deletion import CASCADE, Collector
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from django.db.models.fields.related import (
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ForeignObjectRel, OneToOneField, lazy_related_operation, resolve_relation,
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)
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from django.db.models.manager import Manager
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from django.db.models.options import Options
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from django.db.models.query import Q
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from django.db.models.signals import (
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class_prepared, post_init, post_save, pre_init, pre_save,
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)
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from django.db.models.utils import make_model_tuple
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from django.utils.encoding import force_text
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from django.utils.text import capfirst, get_text_list
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from django.utils.translation import gettext_lazy as _
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from django.utils.version import get_version
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class Deferred:
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def __repr__(self):
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return '<Deferred field>'
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def __str__(self):
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return '<Deferred field>'
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DEFERRED = Deferred()
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def subclass_exception(name, bases, module, attached_to):
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"""
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Create exception subclass. Used by ModelBase below.
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The exception is created in a way that allows it to be pickled, assuming
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that the returned exception class will be added as an attribute to the
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'attached_to' class.
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"""
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return type(name, bases, {
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'__module__': module,
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'__qualname__': '%s.%s' % (attached_to.__qualname__, name),
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})
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class ModelBase(type):
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"""Metaclass for all models."""
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def __new__(cls, name, bases, attrs, **kwargs):
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super_new = super().__new__
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# Also ensure initialization is only performed for subclasses of Model
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# (excluding Model class itself).
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parents = [b for b in bases if isinstance(b, ModelBase)]
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if not parents:
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return super_new(cls, name, bases, attrs)
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# Create the class.
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module = attrs.pop('__module__')
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new_attrs = {'__module__': module}
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classcell = attrs.pop('__classcell__', None)
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if classcell is not None:
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new_attrs['__classcell__'] = classcell
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new_class = super_new(cls, name, bases, new_attrs, **kwargs)
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attr_meta = attrs.pop('Meta', None)
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abstract = getattr(attr_meta, 'abstract', False)
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meta = attr_meta or getattr(new_class, 'Meta', None)
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base_meta = getattr(new_class, '_meta', None)
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app_label = None
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# Look for an application configuration to attach the model to.
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app_config = apps.get_containing_app_config(module)
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if getattr(meta, 'app_label', None) is None:
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if app_config is None:
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if not abstract:
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raise RuntimeError(
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"Model class %s.%s doesn't declare an explicit "
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"app_label and isn't in an application in "
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"INSTALLED_APPS." % (module, name)
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)
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else:
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app_label = app_config.label
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new_class.add_to_class('_meta', Options(meta, app_label))
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if not abstract:
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new_class.add_to_class(
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'DoesNotExist',
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subclass_exception(
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'DoesNotExist',
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tuple(
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x.DoesNotExist for x in parents if hasattr(x, '_meta') and not x._meta.abstract
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) or (ObjectDoesNotExist,),
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module,
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attached_to=new_class))
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new_class.add_to_class(
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'MultipleObjectsReturned',
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subclass_exception(
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'MultipleObjectsReturned',
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tuple(
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x.MultipleObjectsReturned for x in parents if hasattr(x, '_meta') and not x._meta.abstract
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) or (MultipleObjectsReturned,),
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module,
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attached_to=new_class))
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if base_meta and not base_meta.abstract:
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# Non-abstract child classes inherit some attributes from their
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# non-abstract parent (unless an ABC comes before it in the
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# method resolution order).
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if not hasattr(meta, 'ordering'):
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new_class._meta.ordering = base_meta.ordering
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if not hasattr(meta, 'get_latest_by'):
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new_class._meta.get_latest_by = base_meta.get_latest_by
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is_proxy = new_class._meta.proxy
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# If the model is a proxy, ensure that the base class
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# hasn't been swapped out.
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if is_proxy and base_meta and base_meta.swapped:
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raise TypeError("%s cannot proxy the swapped model '%s'." % (name, base_meta.swapped))
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# Add all attributes to the class.
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for obj_name, obj in attrs.items():
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new_class.add_to_class(obj_name, obj)
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# All the fields of any type declared on this model
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new_fields = chain(
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new_class._meta.local_fields,
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new_class._meta.local_many_to_many,
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new_class._meta.private_fields
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)
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field_names = {f.name for f in new_fields}
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# Basic setup for proxy models.
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if is_proxy:
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base = None
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for parent in [kls for kls in parents if hasattr(kls, '_meta')]:
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if parent._meta.abstract:
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if parent._meta.fields:
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raise TypeError(
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"Abstract base class containing model fields not "
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"permitted for proxy model '%s'." % name
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)
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else:
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continue
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if base is None:
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base = parent
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elif parent._meta.concrete_model is not base._meta.concrete_model:
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raise TypeError("Proxy model '%s' has more than one non-abstract model base class." % name)
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if base is None:
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raise TypeError("Proxy model '%s' has no non-abstract model base class." % name)
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new_class._meta.setup_proxy(base)
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new_class._meta.concrete_model = base._meta.concrete_model
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else:
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new_class._meta.concrete_model = new_class
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# Collect the parent links for multi-table inheritance.
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parent_links = {}
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for base in reversed([new_class] + parents):
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# Conceptually equivalent to `if base is Model`.
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if not hasattr(base, '_meta'):
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continue
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# Skip concrete parent classes.
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if base != new_class and not base._meta.abstract:
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continue
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# Locate OneToOneField instances.
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for field in base._meta.local_fields:
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if isinstance(field, OneToOneField):
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related = resolve_relation(new_class, field.remote_field.model)
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parent_links[make_model_tuple(related)] = field
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# Track fields inherited from base models.
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inherited_attributes = set()
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# Do the appropriate setup for any model parents.
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for base in new_class.mro():
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if base not in parents or not hasattr(base, '_meta'):
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# Things without _meta aren't functional models, so they're
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# uninteresting parents.
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inherited_attributes.update(base.__dict__)
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continue
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parent_fields = base._meta.local_fields + base._meta.local_many_to_many
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if not base._meta.abstract:
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# Check for clashes between locally declared fields and those
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# on the base classes.
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for field in parent_fields:
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if field.name in field_names:
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raise FieldError(
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'Local field %r in class %r clashes with field of '
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'the same name from base class %r.' % (
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field.name,
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name,
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base.__name__,
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)
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)
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else:
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inherited_attributes.add(field.name)
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# Concrete classes...
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base = base._meta.concrete_model
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base_key = make_model_tuple(base)
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if base_key in parent_links:
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field = parent_links[base_key]
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elif not is_proxy:
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attr_name = '%s_ptr' % base._meta.model_name
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field = OneToOneField(
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base,
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on_delete=CASCADE,
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name=attr_name,
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auto_created=True,
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parent_link=True,
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)
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if attr_name in field_names:
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raise FieldError(
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"Auto-generated field '%s' in class %r for "
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"parent_link to base class %r clashes with "
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"declared field of the same name." % (
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attr_name,
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name,
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base.__name__,
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)
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)
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# Only add the ptr field if it's not already present;
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# e.g. migrations will already have it specified
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if not hasattr(new_class, attr_name):
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new_class.add_to_class(attr_name, field)
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else:
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field = None
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new_class._meta.parents[base] = field
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else:
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base_parents = base._meta.parents.copy()
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# Add fields from abstract base class if it wasn't overridden.
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for field in parent_fields:
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if (field.name not in field_names and
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field.name not in new_class.__dict__ and
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field.name not in inherited_attributes):
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new_field = copy.deepcopy(field)
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new_class.add_to_class(field.name, new_field)
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# Replace parent links defined on this base by the new
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# field. It will be appropriately resolved if required.
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if field.one_to_one:
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for parent, parent_link in base_parents.items():
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if field == parent_link:
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base_parents[parent] = new_field
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# Pass any non-abstract parent classes onto child.
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new_class._meta.parents.update(base_parents)
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# Inherit private fields (like GenericForeignKey) from the parent
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# class
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for field in base._meta.private_fields:
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if field.name in field_names:
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if not base._meta.abstract:
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raise FieldError(
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'Local field %r in class %r clashes with field of '
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'the same name from base class %r.' % (
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field.name,
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name,
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base.__name__,
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)
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)
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else:
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field = copy.deepcopy(field)
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if not base._meta.abstract:
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field.mti_inherited = True
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new_class.add_to_class(field.name, field)
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# Copy indexes so that index names are unique when models extend an
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# abstract model.
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new_class._meta.indexes = [copy.deepcopy(idx) for idx in new_class._meta.indexes]
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if abstract:
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# Abstract base models can't be instantiated and don't appear in
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# the list of models for an app. We do the final setup for them a
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# little differently from normal models.
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attr_meta.abstract = False
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new_class.Meta = attr_meta
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return new_class
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new_class._prepare()
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new_class._meta.apps.register_model(new_class._meta.app_label, new_class)
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return new_class
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def add_to_class(cls, name, value):
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# We should call the contribute_to_class method only if it's bound
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if not inspect.isclass(value) and hasattr(value, 'contribute_to_class'):
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value.contribute_to_class(cls, name)
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else:
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setattr(cls, name, value)
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def _prepare(cls):
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"""Create some methods once self._meta has been populated."""
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opts = cls._meta
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opts._prepare(cls)
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if opts.order_with_respect_to:
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cls.get_next_in_order = partialmethod(cls._get_next_or_previous_in_order, is_next=True)
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cls.get_previous_in_order = partialmethod(cls._get_next_or_previous_in_order, is_next=False)
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# Defer creating accessors on the foreign class until it has been
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# created and registered. If remote_field is None, we're ordering
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# with respect to a GenericForeignKey and don't know what the
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# foreign class is - we'll add those accessors later in
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# contribute_to_class().
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if opts.order_with_respect_to.remote_field:
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wrt = opts.order_with_respect_to
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remote = wrt.remote_field.model
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lazy_related_operation(make_foreign_order_accessors, cls, remote)
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# Give the class a docstring -- its definition.
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if cls.__doc__ is None:
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cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join(f.name for f in opts.fields))
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get_absolute_url_override = settings.ABSOLUTE_URL_OVERRIDES.get(opts.label_lower)
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if get_absolute_url_override:
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setattr(cls, 'get_absolute_url', get_absolute_url_override)
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if not opts.managers:
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if any(f.name == 'objects' for f in opts.fields):
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raise ValueError(
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"Model %s must specify a custom Manager, because it has a "
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"field named 'objects'." % cls.__name__
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)
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manager = Manager()
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manager.auto_created = True
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cls.add_to_class('objects', manager)
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# Set the name of _meta.indexes. This can't be done in
|
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# Options.contribute_to_class() because fields haven't been added to
|
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# the model at that point.
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for index in cls._meta.indexes:
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if not index.name:
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index.set_name_with_model(cls)
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class_prepared.send(sender=cls)
|
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|
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@property
|
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def _base_manager(cls):
|
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return cls._meta.base_manager
|
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|
|
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@property
|
||
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def _default_manager(cls):
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return cls._meta.default_manager
|
||
|
|
||
|
|
||
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class ModelStateFieldsCacheDescriptor:
|
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def __get__(self, instance, cls=None):
|
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|
if instance is None:
|
||
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return self
|
||
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res = instance.fields_cache = {}
|
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return res
|
||
|
|
||
|
|
||
|
class ModelState:
|
||
|
"""Store model instance state."""
|
||
|
db = None
|
||
|
# If true, uniqueness validation checks will consider this a new, unsaved
|
||
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# object. Necessary for correct validation of new instances of objects with
|
||
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# explicit (non-auto) PKs. This impacts validation only; it has no effect
|
||
|
# on the actual save.
|
||
|
adding = True
|
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fields_cache = ModelStateFieldsCacheDescriptor()
|
||
|
|
||
|
|
||
|
class Model(metaclass=ModelBase):
|
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|
|
||
|
def __init__(self, *args, **kwargs):
|
||
|
# Alias some things as locals to avoid repeat global lookups
|
||
|
cls = self.__class__
|
||
|
opts = self._meta
|
||
|
_setattr = setattr
|
||
|
_DEFERRED = DEFERRED
|
||
|
|
||
|
pre_init.send(sender=cls, args=args, kwargs=kwargs)
|
||
|
|
||
|
# Set up the storage for instance state
|
||
|
self._state = ModelState()
|
||
|
|
||
|
# There is a rather weird disparity here; if kwargs, it's set, then args
|
||
|
# overrides it. It should be one or the other; don't duplicate the work
|
||
|
# The reason for the kwargs check is that standard iterator passes in by
|
||
|
# args, and instantiation for iteration is 33% faster.
|
||
|
if len(args) > len(opts.concrete_fields):
|
||
|
# Daft, but matches old exception sans the err msg.
|
||
|
raise IndexError("Number of args exceeds number of fields")
|
||
|
|
||
|
if not kwargs:
|
||
|
fields_iter = iter(opts.concrete_fields)
|
||
|
# The ordering of the zip calls matter - zip throws StopIteration
|
||
|
# when an iter throws it. So if the first iter throws it, the second
|
||
|
# is *not* consumed. We rely on this, so don't change the order
|
||
|
# without changing the logic.
|
||
|
for val, field in zip(args, fields_iter):
|
||
|
if val is _DEFERRED:
|
||
|
continue
|
||
|
_setattr(self, field.attname, val)
|
||
|
else:
|
||
|
# Slower, kwargs-ready version.
|
||
|
fields_iter = iter(opts.fields)
|
||
|
for val, field in zip(args, fields_iter):
|
||
|
if val is _DEFERRED:
|
||
|
continue
|
||
|
_setattr(self, field.attname, val)
|
||
|
kwargs.pop(field.name, None)
|
||
|
|
||
|
# Now we're left with the unprocessed fields that *must* come from
|
||
|
# keywords, or default.
|
||
|
|
||
|
for field in fields_iter:
|
||
|
is_related_object = False
|
||
|
# Virtual field
|
||
|
if field.attname not in kwargs and field.column is None:
|
||
|
continue
|
||
|
if kwargs:
|
||
|
if isinstance(field.remote_field, ForeignObjectRel):
|
||
|
try:
|
||
|
# Assume object instance was passed in.
|
||
|
rel_obj = kwargs.pop(field.name)
|
||
|
is_related_object = True
|
||
|
except KeyError:
|
||
|
try:
|
||
|
# Object instance wasn't passed in -- must be an ID.
|
||
|
val = kwargs.pop(field.attname)
|
||
|
except KeyError:
|
||
|
val = field.get_default()
|
||
|
else:
|
||
|
# Object instance was passed in. Special case: You can
|
||
|
# pass in "None" for related objects if it's allowed.
|
||
|
if rel_obj is None and field.null:
|
||
|
val = None
|
||
|
else:
|
||
|
try:
|
||
|
val = kwargs.pop(field.attname)
|
||
|
except KeyError:
|
||
|
# This is done with an exception rather than the
|
||
|
# default argument on pop because we don't want
|
||
|
# get_default() to be evaluated, and then not used.
|
||
|
# Refs #12057.
|
||
|
val = field.get_default()
|
||
|
else:
|
||
|
val = field.get_default()
|
||
|
|
||
|
if is_related_object:
|
||
|
# If we are passed a related instance, set it using the
|
||
|
# field.name instead of field.attname (e.g. "user" instead of
|
||
|
# "user_id") so that the object gets properly cached (and type
|
||
|
# checked) by the RelatedObjectDescriptor.
|
||
|
if rel_obj is not _DEFERRED:
|
||
|
_setattr(self, field.name, rel_obj)
|
||
|
else:
|
||
|
if val is not _DEFERRED:
|
||
|
_setattr(self, field.attname, val)
|
||
|
|
||
|
if kwargs:
|
||
|
property_names = opts._property_names
|
||
|
for prop in tuple(kwargs):
|
||
|
try:
|
||
|
# Any remaining kwargs must correspond to properties or
|
||
|
# virtual fields.
|
||
|
if prop in property_names or opts.get_field(prop):
|
||
|
if kwargs[prop] is not _DEFERRED:
|
||
|
_setattr(self, prop, kwargs[prop])
|
||
|
del kwargs[prop]
|
||
|
except (AttributeError, FieldDoesNotExist):
|
||
|
pass
|
||
|
for kwarg in kwargs:
|
||
|
raise TypeError("'%s' is an invalid keyword argument for this function" % kwarg)
|
||
|
super().__init__()
|
||
|
post_init.send(sender=cls, instance=self)
|
||
|
|
||
|
@classmethod
|
||
|
def from_db(cls, db, field_names, values):
|
||
|
if len(values) != len(cls._meta.concrete_fields):
|
||
|
values_iter = iter(values)
|
||
|
values = [
|
||
|
next(values_iter) if f.attname in field_names else DEFERRED
|
||
|
for f in cls._meta.concrete_fields
|
||
|
]
|
||
|
new = cls(*values)
|
||
|
new._state.adding = False
|
||
|
new._state.db = db
|
||
|
return new
|
||
|
|
||
|
def __repr__(self):
|
||
|
return '<%s: %s>' % (self.__class__.__name__, self)
|
||
|
|
||
|
def __str__(self):
|
||
|
return '%s object (%s)' % (self.__class__.__name__, self.pk)
|
||
|
|
||
|
def __eq__(self, other):
|
||
|
if not isinstance(other, Model):
|
||
|
return False
|
||
|
if self._meta.concrete_model != other._meta.concrete_model:
|
||
|
return False
|
||
|
my_pk = self.pk
|
||
|
if my_pk is None:
|
||
|
return self is other
|
||
|
return my_pk == other.pk
|
||
|
|
||
|
def __hash__(self):
|
||
|
if self.pk is None:
|
||
|
raise TypeError("Model instances without primary key value are unhashable")
|
||
|
return hash(self.pk)
|
||
|
|
||
|
def __reduce__(self):
|
||
|
data = self.__getstate__()
|
||
|
data[DJANGO_VERSION_PICKLE_KEY] = get_version()
|
||
|
class_id = self._meta.app_label, self._meta.object_name
|
||
|
return model_unpickle, (class_id,), data
|
||
|
|
||
|
def __getstate__(self):
|
||
|
"""Hook to allow choosing the attributes to pickle."""
|
||
|
return self.__dict__
|
||
|
|
||
|
def __setstate__(self, state):
|
||
|
msg = None
|
||
|
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
|
||
|
if pickled_version:
|
||
|
current_version = get_version()
|
||
|
if current_version != pickled_version:
|
||
|
msg = (
|
||
|
"Pickled model instance's Django version %s does not match "
|
||
|
"the current version %s." % (pickled_version, current_version)
|
||
|
)
|
||
|
else:
|
||
|
msg = "Pickled model instance's Django version is not specified."
|
||
|
|
||
|
if msg:
|
||
|
warnings.warn(msg, RuntimeWarning, stacklevel=2)
|
||
|
|
||
|
self.__dict__.update(state)
|
||
|
|
||
|
def _get_pk_val(self, meta=None):
|
||
|
meta = meta or self._meta
|
||
|
return getattr(self, meta.pk.attname)
|
||
|
|
||
|
def _set_pk_val(self, value):
|
||
|
return setattr(self, self._meta.pk.attname, value)
|
||
|
|
||
|
pk = property(_get_pk_val, _set_pk_val)
|
||
|
|
||
|
def get_deferred_fields(self):
|
||
|
"""
|
||
|
Return a set containing names of deferred fields for this instance.
|
||
|
"""
|
||
|
return {
|
||
|
f.attname for f in self._meta.concrete_fields
|
||
|
if f.attname not in self.__dict__
|
||
|
}
|
||
|
|
||
|
def refresh_from_db(self, using=None, fields=None):
|
||
|
"""
|
||
|
Reload field values from the database.
|
||
|
|
||
|
By default, the reloading happens from the database this instance was
|
||
|
loaded from, or by the read router if this instance wasn't loaded from
|
||
|
any database. The using parameter will override the default.
|
||
|
|
||
|
Fields can be used to specify which fields to reload. The fields
|
||
|
should be an iterable of field attnames. If fields is None, then
|
||
|
all non-deferred fields are reloaded.
|
||
|
|
||
|
When accessing deferred fields of an instance, the deferred loading
|
||
|
of the field will call this method.
|
||
|
"""
|
||
|
if fields is not None:
|
||
|
if not fields:
|
||
|
return
|
||
|
if any(LOOKUP_SEP in f for f in fields):
|
||
|
raise ValueError(
|
||
|
'Found "%s" in fields argument. Relations and transforms '
|
||
|
'are not allowed in fields.' % LOOKUP_SEP)
|
||
|
|
||
|
hints = {'instance': self}
|
||
|
db_instance_qs = self.__class__._base_manager.db_manager(using, hints=hints).filter(pk=self.pk)
|
||
|
|
||
|
# Use provided fields, if not set then reload all non-deferred fields.
|
||
|
deferred_fields = self.get_deferred_fields()
|
||
|
if fields is not None:
|
||
|
fields = list(fields)
|
||
|
db_instance_qs = db_instance_qs.only(*fields)
|
||
|
elif deferred_fields:
|
||
|
fields = [f.attname for f in self._meta.concrete_fields
|
||
|
if f.attname not in deferred_fields]
|
||
|
db_instance_qs = db_instance_qs.only(*fields)
|
||
|
|
||
|
db_instance = db_instance_qs.get()
|
||
|
non_loaded_fields = db_instance.get_deferred_fields()
|
||
|
for field in self._meta.concrete_fields:
|
||
|
if field.attname in non_loaded_fields:
|
||
|
# This field wasn't refreshed - skip ahead.
|
||
|
continue
|
||
|
setattr(self, field.attname, getattr(db_instance, field.attname))
|
||
|
# Clear cached foreign keys.
|
||
|
if field.is_relation and field.is_cached(self):
|
||
|
field.delete_cached_value(self)
|
||
|
|
||
|
# Clear cached relations.
|
||
|
for field in self._meta.related_objects:
|
||
|
if field.is_cached(self):
|
||
|
field.delete_cached_value(self)
|
||
|
|
||
|
self._state.db = db_instance._state.db
|
||
|
|
||
|
def serializable_value(self, field_name):
|
||
|
"""
|
||
|
Return the value of the field name for this instance. If the field is
|
||
|
a foreign key, return the id value instead of the object. If there's
|
||
|
no Field object with this name on the model, return the model
|
||
|
attribute's value.
|
||
|
|
||
|
Used to serialize a field's value (in the serializer, or form output,
|
||
|
for example). Normally, you would just access the attribute directly
|
||
|
and not use this method.
|
||
|
"""
|
||
|
try:
|
||
|
field = self._meta.get_field(field_name)
|
||
|
except FieldDoesNotExist:
|
||
|
return getattr(self, field_name)
|
||
|
return getattr(self, field.attname)
|
||
|
|
||
|
def save(self, force_insert=False, force_update=False, using=None,
|
||
|
update_fields=None):
|
||
|
"""
|
||
|
Save the current instance. Override this in a subclass if you want to
|
||
|
control the saving process.
|
||
|
|
||
|
The 'force_insert' and 'force_update' parameters can be used to insist
|
||
|
that the "save" must be an SQL insert or update (or equivalent for
|
||
|
non-SQL backends), respectively. Normally, they should not be set.
|
||
|
"""
|
||
|
# Ensure that a model instance without a PK hasn't been assigned to
|
||
|
# a ForeignKey or OneToOneField on this model. If the field is
|
||
|
# nullable, allowing the save() would result in silent data loss.
|
||
|
for field in self._meta.concrete_fields:
|
||
|
# If the related field isn't cached, then an instance hasn't
|
||
|
# been assigned and there's no need to worry about this check.
|
||
|
if field.is_relation and field.is_cached(self):
|
||
|
obj = getattr(self, field.name, None)
|
||
|
# A pk may have been assigned manually to a model instance not
|
||
|
# saved to the database (or auto-generated in a case like
|
||
|
# UUIDField), but we allow the save to proceed and rely on the
|
||
|
# database to raise an IntegrityError if applicable. If
|
||
|
# constraints aren't supported by the database, there's the
|
||
|
# unavoidable risk of data corruption.
|
||
|
if obj and obj.pk is None:
|
||
|
# Remove the object from a related instance cache.
|
||
|
if not field.remote_field.multiple:
|
||
|
field.remote_field.delete_cached_value(obj)
|
||
|
raise ValueError(
|
||
|
"save() prohibited to prevent data loss due to "
|
||
|
"unsaved related object '%s'." % field.name
|
||
|
)
|
||
|
# If the relationship's pk/to_field was changed, clear the
|
||
|
# cached relationship.
|
||
|
if obj and getattr(obj, field.target_field.attname) != getattr(self, field.attname):
|
||
|
field.delete_cached_value(self)
|
||
|
|
||
|
using = using or router.db_for_write(self.__class__, instance=self)
|
||
|
if force_insert and (force_update or update_fields):
|
||
|
raise ValueError("Cannot force both insert and updating in model saving.")
|
||
|
|
||
|
deferred_fields = self.get_deferred_fields()
|
||
|
if update_fields is not None:
|
||
|
# If update_fields is empty, skip the save. We do also check for
|
||
|
# no-op saves later on for inheritance cases. This bailout is
|
||
|
# still needed for skipping signal sending.
|
||
|
if not update_fields:
|
||
|
return
|
||
|
|
||
|
update_fields = frozenset(update_fields)
|
||
|
field_names = set()
|
||
|
|
||
|
for field in self._meta.fields:
|
||
|
if not field.primary_key:
|
||
|
field_names.add(field.name)
|
||
|
|
||
|
if field.name != field.attname:
|
||
|
field_names.add(field.attname)
|
||
|
|
||
|
non_model_fields = update_fields.difference(field_names)
|
||
|
|
||
|
if non_model_fields:
|
||
|
raise ValueError("The following fields do not exist in this "
|
||
|
"model or are m2m fields: %s"
|
||
|
% ', '.join(non_model_fields))
|
||
|
|
||
|
# If saving to the same database, and this model is deferred, then
|
||
|
# automatically do a "update_fields" save on the loaded fields.
|
||
|
elif not force_insert and deferred_fields and using == self._state.db:
|
||
|
field_names = set()
|
||
|
for field in self._meta.concrete_fields:
|
||
|
if not field.primary_key and not hasattr(field, 'through'):
|
||
|
field_names.add(field.attname)
|
||
|
loaded_fields = field_names.difference(deferred_fields)
|
||
|
if loaded_fields:
|
||
|
update_fields = frozenset(loaded_fields)
|
||
|
|
||
|
self.save_base(using=using, force_insert=force_insert,
|
||
|
force_update=force_update, update_fields=update_fields)
|
||
|
save.alters_data = True
|
||
|
|
||
|
def save_base(self, raw=False, force_insert=False,
|
||
|
force_update=False, using=None, update_fields=None):
|
||
|
"""
|
||
|
Handle the parts of saving which should be done only once per save,
|
||
|
yet need to be done in raw saves, too. This includes some sanity
|
||
|
checks and signal sending.
|
||
|
|
||
|
The 'raw' argument is telling save_base not to save any parent
|
||
|
models and not to do any changes to the values before save. This
|
||
|
is used by fixture loading.
|
||
|
"""
|
||
|
using = using or router.db_for_write(self.__class__, instance=self)
|
||
|
assert not (force_insert and (force_update or update_fields))
|
||
|
assert update_fields is None or update_fields
|
||
|
cls = origin = self.__class__
|
||
|
# Skip proxies, but keep the origin as the proxy model.
|
||
|
if cls._meta.proxy:
|
||
|
cls = cls._meta.concrete_model
|
||
|
meta = cls._meta
|
||
|
if not meta.auto_created:
|
||
|
pre_save.send(
|
||
|
sender=origin, instance=self, raw=raw, using=using,
|
||
|
update_fields=update_fields,
|
||
|
)
|
||
|
with transaction.atomic(using=using, savepoint=False):
|
||
|
if not raw:
|
||
|
self._save_parents(cls, using, update_fields)
|
||
|
updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
|
||
|
# Store the database on which the object was saved
|
||
|
self._state.db = using
|
||
|
# Once saved, this is no longer a to-be-added instance.
|
||
|
self._state.adding = False
|
||
|
|
||
|
# Signal that the save is complete
|
||
|
if not meta.auto_created:
|
||
|
post_save.send(
|
||
|
sender=origin, instance=self, created=(not updated),
|
||
|
update_fields=update_fields, raw=raw, using=using,
|
||
|
)
|
||
|
|
||
|
save_base.alters_data = True
|
||
|
|
||
|
def _save_parents(self, cls, using, update_fields):
|
||
|
"""Save all the parents of cls using values from self."""
|
||
|
meta = cls._meta
|
||
|
for parent, field in meta.parents.items():
|
||
|
# Make sure the link fields are synced between parent and self.
|
||
|
if (field and getattr(self, parent._meta.pk.attname) is None and
|
||
|
getattr(self, field.attname) is not None):
|
||
|
setattr(self, parent._meta.pk.attname, getattr(self, field.attname))
|
||
|
self._save_parents(cls=parent, using=using, update_fields=update_fields)
|
||
|
self._save_table(cls=parent, using=using, update_fields=update_fields)
|
||
|
# Set the parent's PK value to self.
|
||
|
if field:
|
||
|
setattr(self, field.attname, self._get_pk_val(parent._meta))
|
||
|
# Since we didn't have an instance of the parent handy set
|
||
|
# attname directly, bypassing the descriptor. Invalidate
|
||
|
# the related object cache, in case it's been accidentally
|
||
|
# populated. A fresh instance will be re-built from the
|
||
|
# database if necessary.
|
||
|
if field.is_cached(self):
|
||
|
field.delete_cached_value(self)
|
||
|
|
||
|
def _save_table(self, raw=False, cls=None, force_insert=False,
|
||
|
force_update=False, using=None, update_fields=None):
|
||
|
"""
|
||
|
Do the heavy-lifting involved in saving. Update or insert the data
|
||
|
for a single table.
|
||
|
"""
|
||
|
meta = cls._meta
|
||
|
non_pks = [f for f in meta.local_concrete_fields if not f.primary_key]
|
||
|
|
||
|
if update_fields:
|
||
|
non_pks = [f for f in non_pks
|
||
|
if f.name in update_fields or f.attname in update_fields]
|
||
|
|
||
|
pk_val = self._get_pk_val(meta)
|
||
|
if pk_val is None:
|
||
|
pk_val = meta.pk.get_pk_value_on_save(self)
|
||
|
setattr(self, meta.pk.attname, pk_val)
|
||
|
pk_set = pk_val is not None
|
||
|
if not pk_set and (force_update or update_fields):
|
||
|
raise ValueError("Cannot force an update in save() with no primary key.")
|
||
|
updated = False
|
||
|
# If possible, try an UPDATE. If that doesn't update anything, do an INSERT.
|
||
|
if pk_set and not force_insert:
|
||
|
base_qs = cls._base_manager.using(using)
|
||
|
values = [(f, None, (getattr(self, f.attname) if raw else f.pre_save(self, False)))
|
||
|
for f in non_pks]
|
||
|
forced_update = update_fields or force_update
|
||
|
updated = self._do_update(base_qs, using, pk_val, values, update_fields,
|
||
|
forced_update)
|
||
|
if force_update and not updated:
|
||
|
raise DatabaseError("Forced update did not affect any rows.")
|
||
|
if update_fields and not updated:
|
||
|
raise DatabaseError("Save with update_fields did not affect any rows.")
|
||
|
if not updated:
|
||
|
if meta.order_with_respect_to:
|
||
|
# If this is a model with an order_with_respect_to
|
||
|
# autopopulate the _order field
|
||
|
field = meta.order_with_respect_to
|
||
|
filter_args = field.get_filter_kwargs_for_object(self)
|
||
|
order_value = cls._base_manager.using(using).filter(**filter_args).count()
|
||
|
self._order = order_value
|
||
|
|
||
|
fields = meta.local_concrete_fields
|
||
|
if not pk_set:
|
||
|
fields = [f for f in fields if f is not meta.auto_field]
|
||
|
|
||
|
update_pk = meta.auto_field and not pk_set
|
||
|
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
|
||
|
if update_pk:
|
||
|
setattr(self, meta.pk.attname, result)
|
||
|
return updated
|
||
|
|
||
|
def _do_update(self, base_qs, using, pk_val, values, update_fields, forced_update):
|
||
|
"""
|
||
|
Try to update the model. Return True if the model was updated (if an
|
||
|
update query was done and a matching row was found in the DB).
|
||
|
"""
|
||
|
filtered = base_qs.filter(pk=pk_val)
|
||
|
if not values:
|
||
|
# We can end up here when saving a model in inheritance chain where
|
||
|
# update_fields doesn't target any field in current model. In that
|
||
|
# case we just say the update succeeded. Another case ending up here
|
||
|
# is a model with just PK - in that case check that the PK still
|
||
|
# exists.
|
||
|
return update_fields is not None or filtered.exists()
|
||
|
if self._meta.select_on_save and not forced_update:
|
||
|
return (
|
||
|
filtered.exists() and
|
||
|
# It may happen that the object is deleted from the DB right after
|
||
|
# this check, causing the subsequent UPDATE to return zero matching
|
||
|
# rows. The same result can occur in some rare cases when the
|
||
|
# database returns zero despite the UPDATE being executed
|
||
|
# successfully (a row is matched and updated). In order to
|
||
|
# distinguish these two cases, the object's existence in the
|
||
|
# database is again checked for if the UPDATE query returns 0.
|
||
|
(filtered._update(values) > 0 or filtered.exists())
|
||
|
)
|
||
|
return filtered._update(values) > 0
|
||
|
|
||
|
def _do_insert(self, manager, using, fields, update_pk, raw):
|
||
|
"""
|
||
|
Do an INSERT. If update_pk is defined then this method should return
|
||
|
the new pk for the model.
|
||
|
"""
|
||
|
return manager._insert([self], fields=fields, return_id=update_pk,
|
||
|
using=using, raw=raw)
|
||
|
|
||
|
def delete(self, using=None, keep_parents=False):
|
||
|
using = using or router.db_for_write(self.__class__, instance=self)
|
||
|
assert self.pk is not None, (
|
||
|
"%s object can't be deleted because its %s attribute is set to None." %
|
||
|
(self._meta.object_name, self._meta.pk.attname)
|
||
|
)
|
||
|
|
||
|
collector = Collector(using=using)
|
||
|
collector.collect([self], keep_parents=keep_parents)
|
||
|
return collector.delete()
|
||
|
|
||
|
delete.alters_data = True
|
||
|
|
||
|
def _get_FIELD_display(self, field):
|
||
|
value = getattr(self, field.attname)
|
||
|
return force_text(dict(field.flatchoices).get(value, value), strings_only=True)
|
||
|
|
||
|
def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
|
||
|
if not self.pk:
|
||
|
raise ValueError("get_next/get_previous cannot be used on unsaved objects.")
|
||
|
op = 'gt' if is_next else 'lt'
|
||
|
order = '' if is_next else '-'
|
||
|
param = getattr(self, field.attname)
|
||
|
q = Q(**{'%s__%s' % (field.name, op): param})
|
||
|
q = q | Q(**{field.name: param, 'pk__%s' % op: self.pk})
|
||
|
qs = self.__class__._default_manager.using(self._state.db).filter(**kwargs).filter(q).order_by(
|
||
|
'%s%s' % (order, field.name), '%spk' % order
|
||
|
)
|
||
|
try:
|
||
|
return qs[0]
|
||
|
except IndexError:
|
||
|
raise self.DoesNotExist("%s matching query does not exist." % self.__class__._meta.object_name)
|
||
|
|
||
|
def _get_next_or_previous_in_order(self, is_next):
|
||
|
cachename = "__%s_order_cache" % is_next
|
||
|
if not hasattr(self, cachename):
|
||
|
op = 'gt' if is_next else 'lt'
|
||
|
order = '_order' if is_next else '-_order'
|
||
|
order_field = self._meta.order_with_respect_to
|
||
|
filter_args = order_field.get_filter_kwargs_for_object(self)
|
||
|
obj = self.__class__._default_manager.filter(**filter_args).filter(**{
|
||
|
'_order__%s' % op: self.__class__._default_manager.values('_order').filter(**{
|
||
|
self._meta.pk.name: self.pk
|
||
|
})
|
||
|
}).order_by(order)[:1].get()
|
||
|
setattr(self, cachename, obj)
|
||
|
return getattr(self, cachename)
|
||
|
|
||
|
def prepare_database_save(self, field):
|
||
|
if self.pk is None:
|
||
|
raise ValueError("Unsaved model instance %r cannot be used in an ORM query." % self)
|
||
|
return getattr(self, field.remote_field.get_related_field().attname)
|
||
|
|
||
|
def clean(self):
|
||
|
"""
|
||
|
Hook for doing any extra model-wide validation after clean() has been
|
||
|
called on every field by self.clean_fields. Any ValidationError raised
|
||
|
by this method will not be associated with a particular field; it will
|
||
|
have a special-case association with the field defined by NON_FIELD_ERRORS.
|
||
|
"""
|
||
|
pass
|
||
|
|
||
|
def validate_unique(self, exclude=None):
|
||
|
"""
|
||
|
Check unique constraints on the model and raise ValidationError if any
|
||
|
failed.
|
||
|
"""
|
||
|
unique_checks, date_checks = self._get_unique_checks(exclude=exclude)
|
||
|
|
||
|
errors = self._perform_unique_checks(unique_checks)
|
||
|
date_errors = self._perform_date_checks(date_checks)
|
||
|
|
||
|
for k, v in date_errors.items():
|
||
|
errors.setdefault(k, []).extend(v)
|
||
|
|
||
|
if errors:
|
||
|
raise ValidationError(errors)
|
||
|
|
||
|
def _get_unique_checks(self, exclude=None):
|
||
|
"""
|
||
|
Return a list of checks to perform. Since validate_unique() could be
|
||
|
called from a ModelForm, some fields may have been excluded; we can't
|
||
|
perform a unique check on a model that is missing fields involved
|
||
|
in that check. Fields that did not validate should also be excluded,
|
||
|
but they need to be passed in via the exclude argument.
|
||
|
"""
|
||
|
if exclude is None:
|
||
|
exclude = []
|
||
|
unique_checks = []
|
||
|
|
||
|
unique_togethers = [(self.__class__, self._meta.unique_together)]
|
||
|
for parent_class in self._meta.get_parent_list():
|
||
|
if parent_class._meta.unique_together:
|
||
|
unique_togethers.append((parent_class, parent_class._meta.unique_together))
|
||
|
|
||
|
for model_class, unique_together in unique_togethers:
|
||
|
for check in unique_together:
|
||
|
if not any(name in exclude for name in check):
|
||
|
# Add the check if the field isn't excluded.
|
||
|
unique_checks.append((model_class, tuple(check)))
|
||
|
|
||
|
# These are checks for the unique_for_<date/year/month>.
|
||
|
date_checks = []
|
||
|
|
||
|
# Gather a list of checks for fields declared as unique and add them to
|
||
|
# the list of checks.
|
||
|
|
||
|
fields_with_class = [(self.__class__, self._meta.local_fields)]
|
||
|
for parent_class in self._meta.get_parent_list():
|
||
|
fields_with_class.append((parent_class, parent_class._meta.local_fields))
|
||
|
|
||
|
for model_class, fields in fields_with_class:
|
||
|
for f in fields:
|
||
|
name = f.name
|
||
|
if name in exclude:
|
||
|
continue
|
||
|
if f.unique:
|
||
|
unique_checks.append((model_class, (name,)))
|
||
|
if f.unique_for_date and f.unique_for_date not in exclude:
|
||
|
date_checks.append((model_class, 'date', name, f.unique_for_date))
|
||
|
if f.unique_for_year and f.unique_for_year not in exclude:
|
||
|
date_checks.append((model_class, 'year', name, f.unique_for_year))
|
||
|
if f.unique_for_month and f.unique_for_month not in exclude:
|
||
|
date_checks.append((model_class, 'month', name, f.unique_for_month))
|
||
|
return unique_checks, date_checks
|
||
|
|
||
|
def _perform_unique_checks(self, unique_checks):
|
||
|
errors = {}
|
||
|
|
||
|
for model_class, unique_check in unique_checks:
|
||
|
# Try to look up an existing object with the same values as this
|
||
|
# object's values for all the unique field.
|
||
|
|
||
|
lookup_kwargs = {}
|
||
|
for field_name in unique_check:
|
||
|
f = self._meta.get_field(field_name)
|
||
|
lookup_value = getattr(self, f.attname)
|
||
|
# TODO: Handle multiple backends with different feature flags.
|
||
|
if (lookup_value is None or
|
||
|
(lookup_value == '' and connection.features.interprets_empty_strings_as_nulls)):
|
||
|
# no value, skip the lookup
|
||
|
continue
|
||
|
if f.primary_key and not self._state.adding:
|
||
|
# no need to check for unique primary key when editing
|
||
|
continue
|
||
|
lookup_kwargs[str(field_name)] = lookup_value
|
||
|
|
||
|
# some fields were skipped, no reason to do the check
|
||
|
if len(unique_check) != len(lookup_kwargs):
|
||
|
continue
|
||
|
|
||
|
qs = model_class._default_manager.filter(**lookup_kwargs)
|
||
|
|
||
|
# Exclude the current object from the query if we are editing an
|
||
|
# instance (as opposed to creating a new one)
|
||
|
# Note that we need to use the pk as defined by model_class, not
|
||
|
# self.pk. These can be different fields because model inheritance
|
||
|
# allows single model to have effectively multiple primary keys.
|
||
|
# Refs #17615.
|
||
|
model_class_pk = self._get_pk_val(model_class._meta)
|
||
|
if not self._state.adding and model_class_pk is not None:
|
||
|
qs = qs.exclude(pk=model_class_pk)
|
||
|
if qs.exists():
|
||
|
if len(unique_check) == 1:
|
||
|
key = unique_check[0]
|
||
|
else:
|
||
|
key = NON_FIELD_ERRORS
|
||
|
errors.setdefault(key, []).append(self.unique_error_message(model_class, unique_check))
|
||
|
|
||
|
return errors
|
||
|
|
||
|
def _perform_date_checks(self, date_checks):
|
||
|
errors = {}
|
||
|
for model_class, lookup_type, field, unique_for in date_checks:
|
||
|
lookup_kwargs = {}
|
||
|
# there's a ticket to add a date lookup, we can remove this special
|
||
|
# case if that makes it's way in
|
||
|
date = getattr(self, unique_for)
|
||
|
if date is None:
|
||
|
continue
|
||
|
if lookup_type == 'date':
|
||
|
lookup_kwargs['%s__day' % unique_for] = date.day
|
||
|
lookup_kwargs['%s__month' % unique_for] = date.month
|
||
|
lookup_kwargs['%s__year' % unique_for] = date.year
|
||
|
else:
|
||
|
lookup_kwargs['%s__%s' % (unique_for, lookup_type)] = getattr(date, lookup_type)
|
||
|
lookup_kwargs[field] = getattr(self, field)
|
||
|
|
||
|
qs = model_class._default_manager.filter(**lookup_kwargs)
|
||
|
# Exclude the current object from the query if we are editing an
|
||
|
# instance (as opposed to creating a new one)
|
||
|
if not self._state.adding and self.pk is not None:
|
||
|
qs = qs.exclude(pk=self.pk)
|
||
|
|
||
|
if qs.exists():
|
||
|
errors.setdefault(field, []).append(
|
||
|
self.date_error_message(lookup_type, field, unique_for)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
def date_error_message(self, lookup_type, field_name, unique_for):
|
||
|
opts = self._meta
|
||
|
field = opts.get_field(field_name)
|
||
|
return ValidationError(
|
||
|
message=field.error_messages['unique_for_date'],
|
||
|
code='unique_for_date',
|
||
|
params={
|
||
|
'model': self,
|
||
|
'model_name': capfirst(opts.verbose_name),
|
||
|
'lookup_type': lookup_type,
|
||
|
'field': field_name,
|
||
|
'field_label': capfirst(field.verbose_name),
|
||
|
'date_field': unique_for,
|
||
|
'date_field_label': capfirst(opts.get_field(unique_for).verbose_name),
|
||
|
}
|
||
|
)
|
||
|
|
||
|
def unique_error_message(self, model_class, unique_check):
|
||
|
opts = model_class._meta
|
||
|
|
||
|
params = {
|
||
|
'model': self,
|
||
|
'model_class': model_class,
|
||
|
'model_name': capfirst(opts.verbose_name),
|
||
|
'unique_check': unique_check,
|
||
|
}
|
||
|
|
||
|
# A unique field
|
||
|
if len(unique_check) == 1:
|
||
|
field = opts.get_field(unique_check[0])
|
||
|
params['field_label'] = capfirst(field.verbose_name)
|
||
|
return ValidationError(
|
||
|
message=field.error_messages['unique'],
|
||
|
code='unique',
|
||
|
params=params,
|
||
|
)
|
||
|
|
||
|
# unique_together
|
||
|
else:
|
||
|
field_labels = [capfirst(opts.get_field(f).verbose_name) for f in unique_check]
|
||
|
params['field_labels'] = get_text_list(field_labels, _('and'))
|
||
|
return ValidationError(
|
||
|
message=_("%(model_name)s with this %(field_labels)s already exists."),
|
||
|
code='unique_together',
|
||
|
params=params,
|
||
|
)
|
||
|
|
||
|
def full_clean(self, exclude=None, validate_unique=True):
|
||
|
"""
|
||
|
Call clean_fields(), clean(), and validate_unique() on the model.
|
||
|
Raise a ValidationError for any errors that occur.
|
||
|
"""
|
||
|
errors = {}
|
||
|
if exclude is None:
|
||
|
exclude = []
|
||
|
else:
|
||
|
exclude = list(exclude)
|
||
|
|
||
|
try:
|
||
|
self.clean_fields(exclude=exclude)
|
||
|
except ValidationError as e:
|
||
|
errors = e.update_error_dict(errors)
|
||
|
|
||
|
# Form.clean() is run even if other validation fails, so do the
|
||
|
# same with Model.clean() for consistency.
|
||
|
try:
|
||
|
self.clean()
|
||
|
except ValidationError as e:
|
||
|
errors = e.update_error_dict(errors)
|
||
|
|
||
|
# Run unique checks, but only for fields that passed validation.
|
||
|
if validate_unique:
|
||
|
for name in errors:
|
||
|
if name != NON_FIELD_ERRORS and name not in exclude:
|
||
|
exclude.append(name)
|
||
|
try:
|
||
|
self.validate_unique(exclude=exclude)
|
||
|
except ValidationError as e:
|
||
|
errors = e.update_error_dict(errors)
|
||
|
|
||
|
if errors:
|
||
|
raise ValidationError(errors)
|
||
|
|
||
|
def clean_fields(self, exclude=None):
|
||
|
"""
|
||
|
Clean all fields and raise a ValidationError containing a dict
|
||
|
of all validation errors if any occur.
|
||
|
"""
|
||
|
if exclude is None:
|
||
|
exclude = []
|
||
|
|
||
|
errors = {}
|
||
|
for f in self._meta.fields:
|
||
|
if f.name in exclude:
|
||
|
continue
|
||
|
# Skip validation for empty fields with blank=True. The developer
|
||
|
# is responsible for making sure they have a valid value.
|
||
|
raw_value = getattr(self, f.attname)
|
||
|
if f.blank and raw_value in f.empty_values:
|
||
|
continue
|
||
|
try:
|
||
|
setattr(self, f.attname, f.clean(raw_value, self))
|
||
|
except ValidationError as e:
|
||
|
errors[f.name] = e.error_list
|
||
|
|
||
|
if errors:
|
||
|
raise ValidationError(errors)
|
||
|
|
||
|
@classmethod
|
||
|
def check(cls, **kwargs):
|
||
|
errors = [*cls._check_swappable(), *cls._check_model(), *cls._check_managers(**kwargs)]
|
||
|
if not cls._meta.swapped:
|
||
|
errors += [
|
||
|
*cls._check_fields(**kwargs),
|
||
|
*cls._check_m2m_through_same_relationship(),
|
||
|
*cls._check_long_column_names(),
|
||
|
]
|
||
|
clash_errors = (
|
||
|
*cls._check_id_field(),
|
||
|
*cls._check_field_name_clashes(),
|
||
|
*cls._check_model_name_db_lookup_clashes(),
|
||
|
*cls._check_property_name_related_field_accessor_clashes(),
|
||
|
*cls._check_single_primary_key(),
|
||
|
)
|
||
|
errors.extend(clash_errors)
|
||
|
# If there are field name clashes, hide consequent column name
|
||
|
# clashes.
|
||
|
if not clash_errors:
|
||
|
errors.extend(cls._check_column_name_clashes())
|
||
|
errors += [
|
||
|
*cls._check_index_together(),
|
||
|
*cls._check_unique_together(),
|
||
|
*cls._check_indexes(),
|
||
|
*cls._check_ordering(),
|
||
|
]
|
||
|
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_swappable(cls):
|
||
|
"""Check if the swapped model exists."""
|
||
|
errors = []
|
||
|
if cls._meta.swapped:
|
||
|
try:
|
||
|
apps.get_model(cls._meta.swapped)
|
||
|
except ValueError:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"'%s' is not of the form 'app_label.app_name'." % cls._meta.swappable,
|
||
|
id='models.E001',
|
||
|
)
|
||
|
)
|
||
|
except LookupError:
|
||
|
app_label, model_name = cls._meta.swapped.split('.')
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"'%s' references '%s.%s', which has not been "
|
||
|
"installed, or is abstract." % (
|
||
|
cls._meta.swappable, app_label, model_name
|
||
|
),
|
||
|
id='models.E002',
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_model(cls):
|
||
|
errors = []
|
||
|
if cls._meta.proxy:
|
||
|
if cls._meta.local_fields or cls._meta.local_many_to_many:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"Proxy model '%s' contains model fields." % cls.__name__,
|
||
|
id='models.E017',
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_managers(cls, **kwargs):
|
||
|
"""Perform all manager checks."""
|
||
|
errors = []
|
||
|
for manager in cls._meta.managers:
|
||
|
errors.extend(manager.check(**kwargs))
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_fields(cls, **kwargs):
|
||
|
"""Perform all field checks."""
|
||
|
errors = []
|
||
|
for field in cls._meta.local_fields:
|
||
|
errors.extend(field.check(**kwargs))
|
||
|
for field in cls._meta.local_many_to_many:
|
||
|
errors.extend(field.check(from_model=cls, **kwargs))
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_m2m_through_same_relationship(cls):
|
||
|
""" Check if no relationship model is used by more than one m2m field.
|
||
|
"""
|
||
|
|
||
|
errors = []
|
||
|
seen_intermediary_signatures = []
|
||
|
|
||
|
fields = cls._meta.local_many_to_many
|
||
|
|
||
|
# Skip when the target model wasn't found.
|
||
|
fields = (f for f in fields if isinstance(f.remote_field.model, ModelBase))
|
||
|
|
||
|
# Skip when the relationship model wasn't found.
|
||
|
fields = (f for f in fields if isinstance(f.remote_field.through, ModelBase))
|
||
|
|
||
|
for f in fields:
|
||
|
signature = (f.remote_field.model, cls, f.remote_field.through)
|
||
|
if signature in seen_intermediary_signatures:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The model has two many-to-many relations through "
|
||
|
"the intermediate model '%s'." % f.remote_field.through._meta.label,
|
||
|
obj=cls,
|
||
|
id='models.E003',
|
||
|
)
|
||
|
)
|
||
|
else:
|
||
|
seen_intermediary_signatures.append(signature)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_id_field(cls):
|
||
|
"""Check if `id` field is a primary key."""
|
||
|
fields = [f for f in cls._meta.local_fields if f.name == 'id' and f != cls._meta.pk]
|
||
|
# fields is empty or consists of the invalid "id" field
|
||
|
if fields and not fields[0].primary_key and cls._meta.pk.name == 'id':
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"'id' can only be used as a field name if the field also "
|
||
|
"sets 'primary_key=True'.",
|
||
|
obj=cls,
|
||
|
id='models.E004',
|
||
|
)
|
||
|
]
|
||
|
else:
|
||
|
return []
|
||
|
|
||
|
@classmethod
|
||
|
def _check_field_name_clashes(cls):
|
||
|
"""Forbid field shadowing in multi-table inheritance."""
|
||
|
errors = []
|
||
|
used_fields = {} # name or attname -> field
|
||
|
|
||
|
# Check that multi-inheritance doesn't cause field name shadowing.
|
||
|
for parent in cls._meta.get_parent_list():
|
||
|
for f in parent._meta.local_fields:
|
||
|
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
|
||
|
if clash:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The field '%s' from parent model "
|
||
|
"'%s' clashes with the field '%s' "
|
||
|
"from parent model '%s'." % (
|
||
|
clash.name, clash.model._meta,
|
||
|
f.name, f.model._meta
|
||
|
),
|
||
|
obj=cls,
|
||
|
id='models.E005',
|
||
|
)
|
||
|
)
|
||
|
used_fields[f.name] = f
|
||
|
used_fields[f.attname] = f
|
||
|
|
||
|
# Check that fields defined in the model don't clash with fields from
|
||
|
# parents, including auto-generated fields like multi-table inheritance
|
||
|
# child accessors.
|
||
|
for parent in cls._meta.get_parent_list():
|
||
|
for f in parent._meta.get_fields():
|
||
|
if f not in used_fields:
|
||
|
used_fields[f.name] = f
|
||
|
|
||
|
for f in cls._meta.local_fields:
|
||
|
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
|
||
|
# Note that we may detect clash between user-defined non-unique
|
||
|
# field "id" and automatically added unique field "id", both
|
||
|
# defined at the same model. This special case is considered in
|
||
|
# _check_id_field and here we ignore it.
|
||
|
id_conflict = f.name == "id" and clash and clash.name == "id" and clash.model == cls
|
||
|
if clash and not id_conflict:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The field '%s' clashes with the field '%s' "
|
||
|
"from model '%s'." % (
|
||
|
f.name, clash.name, clash.model._meta
|
||
|
),
|
||
|
obj=f,
|
||
|
id='models.E006',
|
||
|
)
|
||
|
)
|
||
|
used_fields[f.name] = f
|
||
|
used_fields[f.attname] = f
|
||
|
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_column_name_clashes(cls):
|
||
|
# Store a list of column names which have already been used by other fields.
|
||
|
used_column_names = []
|
||
|
errors = []
|
||
|
|
||
|
for f in cls._meta.local_fields:
|
||
|
_, column_name = f.get_attname_column()
|
||
|
|
||
|
# Ensure the column name is not already in use.
|
||
|
if column_name and column_name in used_column_names:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"Field '%s' has column name '%s' that is used by "
|
||
|
"another field." % (f.name, column_name),
|
||
|
hint="Specify a 'db_column' for the field.",
|
||
|
obj=cls,
|
||
|
id='models.E007'
|
||
|
)
|
||
|
)
|
||
|
else:
|
||
|
used_column_names.append(column_name)
|
||
|
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_model_name_db_lookup_clashes(cls):
|
||
|
errors = []
|
||
|
model_name = cls.__name__
|
||
|
if model_name.startswith('_') or model_name.endswith('_'):
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The model name '%s' cannot start or end with an underscore "
|
||
|
"as it collides with the query lookup syntax." % model_name,
|
||
|
obj=cls,
|
||
|
id='models.E023'
|
||
|
)
|
||
|
)
|
||
|
elif LOOKUP_SEP in model_name:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The model name '%s' cannot contain double underscores as "
|
||
|
"it collides with the query lookup syntax." % model_name,
|
||
|
obj=cls,
|
||
|
id='models.E024'
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_property_name_related_field_accessor_clashes(cls):
|
||
|
errors = []
|
||
|
property_names = cls._meta._property_names
|
||
|
related_field_accessors = (
|
||
|
f.get_attname() for f in cls._meta._get_fields(reverse=False)
|
||
|
if f.is_relation and f.related_model is not None
|
||
|
)
|
||
|
for accessor in related_field_accessors:
|
||
|
if accessor in property_names:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The property '%s' clashes with a related field "
|
||
|
"accessor." % accessor,
|
||
|
obj=cls,
|
||
|
id='models.E025',
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_single_primary_key(cls):
|
||
|
errors = []
|
||
|
if sum(1 for f in cls._meta.local_fields if f.primary_key) > 1:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"The model cannot have more than one field with "
|
||
|
"'primary_key=True'.",
|
||
|
obj=cls,
|
||
|
id='models.E026',
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_index_together(cls):
|
||
|
"""Check the value of "index_together" option."""
|
||
|
if not isinstance(cls._meta.index_together, (tuple, list)):
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"'index_together' must be a list or tuple.",
|
||
|
obj=cls,
|
||
|
id='models.E008',
|
||
|
)
|
||
|
]
|
||
|
|
||
|
elif any(not isinstance(fields, (tuple, list)) for fields in cls._meta.index_together):
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"All 'index_together' elements must be lists or tuples.",
|
||
|
obj=cls,
|
||
|
id='models.E009',
|
||
|
)
|
||
|
]
|
||
|
|
||
|
else:
|
||
|
errors = []
|
||
|
for fields in cls._meta.index_together:
|
||
|
errors.extend(cls._check_local_fields(fields, "index_together"))
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_unique_together(cls):
|
||
|
"""Check the value of "unique_together" option."""
|
||
|
if not isinstance(cls._meta.unique_together, (tuple, list)):
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"'unique_together' must be a list or tuple.",
|
||
|
obj=cls,
|
||
|
id='models.E010',
|
||
|
)
|
||
|
]
|
||
|
|
||
|
elif any(not isinstance(fields, (tuple, list)) for fields in cls._meta.unique_together):
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"All 'unique_together' elements must be lists or tuples.",
|
||
|
obj=cls,
|
||
|
id='models.E011',
|
||
|
)
|
||
|
]
|
||
|
|
||
|
else:
|
||
|
errors = []
|
||
|
for fields in cls._meta.unique_together:
|
||
|
errors.extend(cls._check_local_fields(fields, "unique_together"))
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_indexes(cls):
|
||
|
"""Check the fields of indexes."""
|
||
|
fields = [field for index in cls._meta.indexes for field, _ in index.fields_orders]
|
||
|
return cls._check_local_fields(fields, 'indexes')
|
||
|
|
||
|
@classmethod
|
||
|
def _check_local_fields(cls, fields, option):
|
||
|
from django.db import models
|
||
|
|
||
|
# In order to avoid hitting the relation tree prematurely, we use our
|
||
|
# own fields_map instead of using get_field()
|
||
|
forward_fields_map = {
|
||
|
field.name: field for field in cls._meta._get_fields(reverse=False)
|
||
|
}
|
||
|
|
||
|
errors = []
|
||
|
for field_name in fields:
|
||
|
try:
|
||
|
field = forward_fields_map[field_name]
|
||
|
except KeyError:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"'%s' refers to the nonexistent field '%s'." % (
|
||
|
option, field_name,
|
||
|
),
|
||
|
obj=cls,
|
||
|
id='models.E012',
|
||
|
)
|
||
|
)
|
||
|
else:
|
||
|
if isinstance(field.remote_field, models.ManyToManyRel):
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"'%s' refers to a ManyToManyField '%s', but "
|
||
|
"ManyToManyFields are not permitted in '%s'." % (
|
||
|
option, field_name, option,
|
||
|
),
|
||
|
obj=cls,
|
||
|
id='models.E013',
|
||
|
)
|
||
|
)
|
||
|
elif field not in cls._meta.local_fields:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"'%s' refers to field '%s' which is not local to model '%s'."
|
||
|
% (option, field_name, cls._meta.object_name),
|
||
|
hint="This issue may be caused by multi-table inheritance.",
|
||
|
obj=cls,
|
||
|
id='models.E016',
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_ordering(cls):
|
||
|
"""
|
||
|
Check "ordering" option -- is it a list of strings and do all fields
|
||
|
exist?
|
||
|
"""
|
||
|
if cls._meta._ordering_clash:
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"'ordering' and 'order_with_respect_to' cannot be used together.",
|
||
|
obj=cls,
|
||
|
id='models.E021',
|
||
|
),
|
||
|
]
|
||
|
|
||
|
if cls._meta.order_with_respect_to or not cls._meta.ordering:
|
||
|
return []
|
||
|
|
||
|
if not isinstance(cls._meta.ordering, (list, tuple)):
|
||
|
return [
|
||
|
checks.Error(
|
||
|
"'ordering' must be a tuple or list (even if you want to order by only one field).",
|
||
|
obj=cls,
|
||
|
id='models.E014',
|
||
|
)
|
||
|
]
|
||
|
|
||
|
errors = []
|
||
|
fields = cls._meta.ordering
|
||
|
|
||
|
# Skip expressions and '?' fields.
|
||
|
fields = (f for f in fields if isinstance(f, str) and f != '?')
|
||
|
|
||
|
# Convert "-field" to "field".
|
||
|
fields = ((f[1:] if f.startswith('-') else f) for f in fields)
|
||
|
|
||
|
# Skip ordering in the format field1__field2 (FIXME: checking
|
||
|
# this format would be nice, but it's a little fiddly).
|
||
|
fields = (f for f in fields if LOOKUP_SEP not in f)
|
||
|
|
||
|
# Skip ordering on pk. This is always a valid order_by field
|
||
|
# but is an alias and therefore won't be found by opts.get_field.
|
||
|
fields = {f for f in fields if f != 'pk'}
|
||
|
|
||
|
# Check for invalid or nonexistent fields in ordering.
|
||
|
invalid_fields = []
|
||
|
|
||
|
# Any field name that is not present in field_names does not exist.
|
||
|
# Also, ordering by m2m fields is not allowed.
|
||
|
opts = cls._meta
|
||
|
valid_fields = set(chain.from_iterable(
|
||
|
(f.name, f.attname) if not (f.auto_created and not f.concrete) else (f.field.related_query_name(),)
|
||
|
for f in chain(opts.fields, opts.related_objects)
|
||
|
))
|
||
|
|
||
|
invalid_fields.extend(fields - valid_fields)
|
||
|
|
||
|
for invalid_field in invalid_fields:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
"'ordering' refers to the nonexistent field '%s'." % invalid_field,
|
||
|
obj=cls,
|
||
|
id='models.E015',
|
||
|
)
|
||
|
)
|
||
|
return errors
|
||
|
|
||
|
@classmethod
|
||
|
def _check_long_column_names(cls):
|
||
|
"""
|
||
|
Check that any auto-generated column names are shorter than the limits
|
||
|
for each database in which the model will be created.
|
||
|
"""
|
||
|
errors = []
|
||
|
allowed_len = None
|
||
|
db_alias = None
|
||
|
|
||
|
# Find the minimum max allowed length among all specified db_aliases.
|
||
|
for db in settings.DATABASES:
|
||
|
# skip databases where the model won't be created
|
||
|
if not router.allow_migrate_model(db, cls):
|
||
|
continue
|
||
|
connection = connections[db]
|
||
|
max_name_length = connection.ops.max_name_length()
|
||
|
if max_name_length is None or connection.features.truncates_names:
|
||
|
continue
|
||
|
else:
|
||
|
if allowed_len is None:
|
||
|
allowed_len = max_name_length
|
||
|
db_alias = db
|
||
|
elif max_name_length < allowed_len:
|
||
|
allowed_len = max_name_length
|
||
|
db_alias = db
|
||
|
|
||
|
if allowed_len is None:
|
||
|
return errors
|
||
|
|
||
|
for f in cls._meta.local_fields:
|
||
|
_, column_name = f.get_attname_column()
|
||
|
|
||
|
# Check if auto-generated name for the field is too long
|
||
|
# for the database.
|
||
|
if f.db_column is None and column_name is not None and len(column_name) > allowed_len:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
'Autogenerated column name too long for field "%s". '
|
||
|
'Maximum length is "%s" for database "%s".'
|
||
|
% (column_name, allowed_len, db_alias),
|
||
|
hint="Set the column name manually using 'db_column'.",
|
||
|
obj=cls,
|
||
|
id='models.E018',
|
||
|
)
|
||
|
)
|
||
|
|
||
|
for f in cls._meta.local_many_to_many:
|
||
|
# Skip nonexistent models.
|
||
|
if isinstance(f.remote_field.through, str):
|
||
|
continue
|
||
|
|
||
|
# Check if auto-generated name for the M2M field is too long
|
||
|
# for the database.
|
||
|
for m2m in f.remote_field.through._meta.local_fields:
|
||
|
_, rel_name = m2m.get_attname_column()
|
||
|
if m2m.db_column is None and rel_name is not None and len(rel_name) > allowed_len:
|
||
|
errors.append(
|
||
|
checks.Error(
|
||
|
'Autogenerated column name too long for M2M field '
|
||
|
'"%s". Maximum length is "%s" for database "%s".'
|
||
|
% (rel_name, allowed_len, db_alias),
|
||
|
hint=(
|
||
|
"Use 'through' to create a separate model for "
|
||
|
"M2M and then set column_name using 'db_column'."
|
||
|
),
|
||
|
obj=cls,
|
||
|
id='models.E019',
|
||
|
)
|
||
|
)
|
||
|
|
||
|
return errors
|
||
|
|
||
|
|
||
|
############################################
|
||
|
# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
|
||
|
############################################
|
||
|
|
||
|
# ORDERING METHODS #########################
|
||
|
|
||
|
def method_set_order(self, ordered_obj, id_list, using=None):
|
||
|
if using is None:
|
||
|
using = DEFAULT_DB_ALIAS
|
||
|
order_wrt = ordered_obj._meta.order_with_respect_to
|
||
|
filter_args = order_wrt.get_forward_related_filter(self)
|
||
|
# FIXME: It would be nice if there was an "update many" version of update
|
||
|
# for situations like this.
|
||
|
with transaction.atomic(using=using, savepoint=False):
|
||
|
for i, j in enumerate(id_list):
|
||
|
ordered_obj.objects.filter(pk=j, **filter_args).update(_order=i)
|
||
|
|
||
|
|
||
|
def method_get_order(self, ordered_obj):
|
||
|
order_wrt = ordered_obj._meta.order_with_respect_to
|
||
|
filter_args = order_wrt.get_forward_related_filter(self)
|
||
|
pk_name = ordered_obj._meta.pk.name
|
||
|
return ordered_obj.objects.filter(**filter_args).values_list(pk_name, flat=True)
|
||
|
|
||
|
|
||
|
def make_foreign_order_accessors(model, related_model):
|
||
|
setattr(
|
||
|
related_model,
|
||
|
'get_%s_order' % model.__name__.lower(),
|
||
|
partialmethod(method_get_order, model)
|
||
|
)
|
||
|
setattr(
|
||
|
related_model,
|
||
|
'set_%s_order' % model.__name__.lower(),
|
||
|
partialmethod(method_set_order, model)
|
||
|
)
|
||
|
|
||
|
########
|
||
|
# MISC #
|
||
|
########
|
||
|
|
||
|
|
||
|
def model_unpickle(model_id):
|
||
|
"""Used to unpickle Model subclasses with deferred fields."""
|
||
|
if isinstance(model_id, tuple):
|
||
|
model = apps.get_model(*model_id)
|
||
|
else:
|
||
|
# Backwards compat - the model was cached directly in earlier versions.
|
||
|
model = model_id
|
||
|
return model.__new__(model)
|
||
|
|
||
|
|
||
|
model_unpickle.__safe_for_unpickle__ = True
|