django1/django/db/models/base.py

1049 lines
45 KiB
Python

from __future__ import unicode_literals
import copy
import sys
from functools import update_wrapper
from django.utils.six.moves import zip
import django.db.models.manager # Imported to register signal handler.
from django.conf import settings
from django.core.exceptions import (ObjectDoesNotExist,
MultipleObjectsReturned, FieldError, ValidationError, NON_FIELD_ERRORS)
from django.db.models.fields import AutoField, FieldDoesNotExist
from django.db.models.fields.related import (ForeignObjectRel, ManyToOneRel,
OneToOneField, add_lazy_relation)
from django.db import (router, transaction, DatabaseError,
DEFAULT_DB_ALIAS)
from django.db.models.query import Q
from django.db.models.query_utils import DeferredAttribute, deferred_class_factory
from django.db.models.deletion import Collector
from django.db.models.options import Options
from django.db.models import signals
from django.db.models.loading import register_models, get_model, MODELS_MODULE_NAME
from django.utils.translation import ugettext_lazy as _
from django.utils.functional import curry
from django.utils.encoding import force_str, force_text
from django.utils import six
from django.utils.text import get_text_list, capfirst
def subclass_exception(name, parents, module, attached_to=None):
"""
Create exception subclass. Used by ModelBase below.
If 'attached_to' is supplied, the exception will be created in a way that
allows it to be pickled, assuming the returned exception class will be added
as an attribute to the 'attached_to' class.
"""
class_dict = {'__module__': module}
if attached_to is not None:
def __reduce__(self):
# Exceptions are special - they've got state that isn't
# in self.__dict__. We assume it is all in self.args.
return (unpickle_inner_exception, (attached_to, name), self.args)
def __setstate__(self, args):
self.args = args
class_dict['__reduce__'] = __reduce__
class_dict['__setstate__'] = __setstate__
return type(name, parents, class_dict)
class ModelBase(type):
"""
Metaclass for all models.
"""
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. But the initialization
# should be executed only once for a given model class.
# attrs will never be empty for classes declared in the standard way
# (ie. with the `class` keyword). This is quite robust.
if name == 'NewBase' and attrs == {}:
return super_new(cls, name, bases, attrs)
# Also ensure initialization is only performed for subclasses of Model
# (excluding Model class itself).
parents = [b for b in bases if isinstance(b, ModelBase) and
not (b.__name__ == 'NewBase' and b.__mro__ == (b, object))]
if not parents:
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 from the package
# or module named 'models'. If no such package or module exists,
# fall back to looking one level up from the module this model is
# defined in.
# For 'django.contrib.sites.models', this would be 'sites'.
# For 'geo.models.places' this would be 'geo'.
model_module = sys.modules[new_class.__module__]
package_components = model_module.__name__.split('.')
package_components.reverse() # find the last occurrence of 'models'
try:
app_label_index = package_components.index(MODELS_MODULE_NAME) + 1
except ValueError:
app_label_index = 1
kwargs = {"app_label": package_components[app_label_index]}
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 the model is a proxy, ensure that the base class
# hasn't been swapped out.
if is_proxy and base_meta and base_meta.swapped:
raise TypeError("%s cannot proxy the swapped model '%s'." % (name, base_meta.swapped))
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 = new_class._meta.app_cache.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.model_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()
new_class._meta.app_cache.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 new_class._meta.app_cache.get_model(new_class._meta.app_label, name,
seed_cache=False, only_installed=False)
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 add_to_class(cls, name, value):
if hasattr(value, 'contribute_to_class'):
value.contribute_to_class(cls, name)
else:
setattr(cls, name, value)
def _prepare(cls):
"""
Creates some methods once self._meta has been populated.
"""
opts = cls._meta
opts._prepare(cls)
if opts.order_with_respect_to:
cls.get_next_in_order = curry(cls._get_next_or_previous_in_order, is_next=True)
cls.get_previous_in_order = curry(cls._get_next_or_previous_in_order, is_next=False)
# defer creating accessors on the foreign class until we are
# certain it has been created
def make_foreign_order_accessors(field, model, cls):
setattr(
field.rel.to,
'get_%s_order' % cls.__name__.lower(),
curry(method_get_order, cls)
)
setattr(
field.rel.to,
'set_%s_order' % cls.__name__.lower(),
curry(method_set_order, cls)
)
add_lazy_relation(
cls,
opts.order_with_respect_to,
opts.order_with_respect_to.rel.to,
make_foreign_order_accessors
)
# Give the class a docstring -- its definition.
if cls.__doc__ is None:
cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join([f.attname for f in opts.fields]))
if hasattr(cls, 'get_absolute_url'):
cls.get_absolute_url = update_wrapper(curry(get_absolute_url, opts, cls.get_absolute_url),
cls.get_absolute_url)
signals.class_prepared.send(sender=cls)
class ModelState(object):
"""
A class for storing instance state
"""
def __init__(self, db=None):
self.db = db
# If true, uniqueness validation checks will consider this a new, as-yet-unsaved object.
# Necessary for correct validation of new instances of objects with explicit (non-auto) PKs.
# This impacts validation only; it has no effect on the actual save.
self.adding = True
class Model(six.with_metaclass(ModelBase)):
_deferred = False
def __init__(self, *args, **kwargs):
signals.pre_init.send(sender=self.__class__, 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.
args_len = len(args)
if args_len > len(self._meta.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(self._meta.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):
setattr(self, field.attname, val)
else:
# Slower, kwargs-ready version.
fields_iter = iter(self._meta.fields)
for val, field in zip(args, fields_iter):
setattr(self, field.attname, val)
kwargs.pop(field.name, None)
# Maintain compatibility with existing calls.
if isinstance(field.rel, ManyToOneRel):
kwargs.pop(field.attname, 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
# This slightly odd construct is so that we can access any
# data-descriptor object (DeferredAttribute) without triggering its
# __get__ method.
if (field.attname not in kwargs and
(isinstance(self.__class__.__dict__.get(field.attname), DeferredAttribute)
or field.column is None)):
# This field will be populated on request.
continue
if kwargs:
if isinstance(field.rel, 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.
setattr(self, field.name, rel_obj)
else:
setattr(self, field.attname, val)
if kwargs:
for prop in list(kwargs):
try:
if isinstance(getattr(self.__class__, prop), property):
setattr(self, prop, kwargs.pop(prop))
except AttributeError:
pass
if kwargs:
raise TypeError("'%s' is an invalid keyword argument for this function" % list(kwargs)[0])
super(Model, self).__init__()
signals.post_init.send(sender=self.__class__, instance=self)
def __repr__(self):
try:
u = six.text_type(self)
except (UnicodeEncodeError, UnicodeDecodeError):
u = '[Bad Unicode data]'
return force_str('<%s: %s>' % (self.__class__.__name__, u))
def __str__(self):
if not six.PY3 and hasattr(self, '__unicode__'):
if type(self).__unicode__ == Model.__str__:
klass_name = type(self).__name__
raise RuntimeError("%s.__unicode__ is aliased to __str__. Did"
" you apply @python_2_unicode_compatible"
" without defining __str__?" % klass_name)
return force_text(self).encode('utf-8')
return '%s object' % self.__class__.__name__
def __eq__(self, other):
return isinstance(other, self.__class__) and self._get_pk_val() == other._get_pk_val()
def __ne__(self, other):
return not self.__eq__(other)
def __hash__(self):
return hash(self._get_pk_val())
def __reduce__(self):
"""
Provides pickling support. Normally, this just dispatches to Python's
standard handling. However, for models with deferred field loading, we
need to do things manually, as they're dynamically created classes and
only module-level classes can be pickled by the default path.
"""
data = self.__dict__
if not self._deferred:
class_id = self._meta.app_label, self._meta.object_name
return model_unpickle, (class_id, [], simple_class_factory), data
defers = []
for field in self._meta.fields:
if isinstance(self.__class__.__dict__.get(field.attname),
DeferredAttribute):
defers.append(field.attname)
model = self._meta.proxy_for_model
class_id = model._meta.app_label, model._meta.object_name
return (model_unpickle, (class_id, defers, deferred_class_factory), data)
def _get_pk_val(self, meta=None):
if not meta:
meta = 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 serializable_value(self, field_name):
"""
Returns the value of the field name for this instance. If the field is
a foreign key, returns the id value, instead of the object. If there's
no Field object with this name on the model, the model attribute's
value is returned directly.
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_by_name(field_name)[0]
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):
"""
Saves 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.
"""
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.")
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 len(update_fields) == 0:
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 self._deferred 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)
deferred_fields = [
f.attname for f in self._meta.fields
if f.attname not in self.__dict__
and isinstance(self.__class__.__dict__[f.attname],
DeferredAttribute)]
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):
"""
Handles 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 len(update_fields) > 0
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:
signals.pre_save.send(sender=origin, instance=self, raw=raw, using=using,
update_fields=update_fields)
with transaction.commit_on_success_unless_managed(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:
signals.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):
"""
Saves 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.
cache_name = field.get_cache_name()
if hasattr(self, cache_name):
delattr(self, cache_name)
def _save_table(self, raw=False, cls=None, force_insert=False,
force_update=False, using=None, update_fields=None):
"""
Does the heavy-lifting involved in saving. Updates or inserts 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)
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]
updated = self._do_update(base_qs, using, pk_val, values, update_fields)
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
order_value = cls._base_manager.using(using).filter(
**{field.name: getattr(self, field.attname)}).count()
self._order = order_value
fields = meta.local_concrete_fields
if not pk_set:
fields = [f for f in fields if not isinstance(f, AutoField)]
update_pk = bool(meta.has_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):
"""
This method will try to update the model. If the model was updated (in
the sense that an update query was done and a matching row was found
from the DB) the method will return True.
"""
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 base_qs.filter(pk=pk_val).exists()
else:
return base_qs.filter(pk=pk_val)._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):
using = using or router.db_for_write(self.__class__, instance=self)
assert self._get_pk_val() 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])
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 = force_text(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
obj = self._default_manager.filter(**{
order_field.name: getattr(self, order_field.attname)
}).filter(**{
'_order__%s' % op: self._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, unused):
return self.pk
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):
"""
Checks unique constraints on the model and raises ``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):
"""
Gather 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.parents.keys():
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:
for name in check:
# If this is an excluded field, don't add this check.
if name in exclude:
break
else:
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.parents.keys():
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)
if lookup_value is None:
# 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, unique_for):
opts = self._meta
return _("%(field_name)s must be unique for %(date_field)s %(lookup)s.") % {
'field_name': six.text_type(capfirst(opts.get_field(field).verbose_name)),
'date_field': six.text_type(capfirst(opts.get_field(unique_for).verbose_name)),
'lookup': lookup_type,
}
def unique_error_message(self, model_class, unique_check):
opts = model_class._meta
model_name = capfirst(opts.verbose_name)
# A unique field
if len(unique_check) == 1:
field_name = unique_check[0]
field = opts.get_field(field_name)
field_label = capfirst(field.verbose_name)
# Insert the error into the error dict, very sneaky
return field.error_messages['unique'] % {
'model_name': six.text_type(model_name),
'field_label': six.text_type(field_label)
}
# unique_together
else:
field_labels = [capfirst(opts.get_field(f).verbose_name) for f in unique_check]
field_labels = get_text_list(field_labels, _('and'))
return _("%(model_name)s with this %(field_label)s already exists.") % {
'model_name': six.text_type(model_name),
'field_label': six.text_type(field_labels)
}
def full_clean(self, exclude=None, validate_unique=True):
"""
Calls clean_fields, clean, and validate_unique, on the model,
and raises a ``ValidationError`` for any errors that occurred.
"""
errors = {}
if exclude is None:
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.keys():
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):
"""
Cleans all fields and raises a ValidationError containing message_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)
############################################
# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
############################################
# ORDERING METHODS #########################
def method_set_order(ordered_obj, self, id_list, using=None):
if using is None:
using = DEFAULT_DB_ALIAS
rel_val = getattr(self, ordered_obj._meta.order_with_respect_to.rel.field_name)
order_name = ordered_obj._meta.order_with_respect_to.name
# FIXME: It would be nice if there was an "update many" version of update
# for situations like this.
with transaction.commit_on_success_unless_managed(using=using):
for i, j in enumerate(id_list):
ordered_obj.objects.filter(**{'pk': j, order_name: rel_val}).update(_order=i)
def method_get_order(ordered_obj, self):
rel_val = getattr(self, ordered_obj._meta.order_with_respect_to.rel.field_name)
order_name = ordered_obj._meta.order_with_respect_to.name
pk_name = ordered_obj._meta.pk.name
return [r[pk_name] for r in
ordered_obj.objects.filter(**{order_name: rel_val}).values(pk_name)]
##############################################
# HELPER FUNCTIONS (CURRIED MODEL FUNCTIONS) #
##############################################
def get_absolute_url(opts, func, self, *args, **kwargs):
return settings.ABSOLUTE_URL_OVERRIDES.get('%s.%s' % (opts.app_label, opts.model_name), func)(self, *args, **kwargs)
########
# MISC #
########
def simple_class_factory(model, attrs):
"""
Needed for dynamic classes.
"""
return model
def model_unpickle(model_id, attrs, factory):
"""
Used to unpickle Model subclasses with deferred fields.
"""
if isinstance(model_id, tuple):
model = get_model(*model_id)
else:
# Backwards compat - the model was cached directly in earlier versions.
model = model_id
cls = factory(model, attrs)
return cls.__new__(cls)
model_unpickle.__safe_for_unpickle__ = True
def unpickle_inner_exception(klass, exception_name):
# Get the exception class from the class it is attached to:
exception = getattr(klass, exception_name)
return exception.__new__(exception)