1563 lines
71 KiB
Python
1563 lines
71 KiB
Python
from operator import attrgetter
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from django.db import connection, connections, router
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from django.db.backends import util
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from django.db.models import signals, get_model
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from django.db.models.fields import (AutoField, Field, IntegerField,
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PositiveIntegerField, PositiveSmallIntegerField, FieldDoesNotExist)
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from django.db.models.related import RelatedObject, PathInfo
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from django.db.models.query import QuerySet
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from django.db.models.deletion import CASCADE
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from django.utils.encoding import smart_text
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from django.utils import six
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from django.utils.deprecation import RenameMethodsBase
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from django.utils.translation import ugettext_lazy as _
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from django.utils.functional import curry, cached_property
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from django.core import exceptions
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from django import forms
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RECURSIVE_RELATIONSHIP_CONSTANT = 'self'
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pending_lookups = {}
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def add_lazy_relation(cls, field, relation, operation):
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"""
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Adds a lookup on ``cls`` when a related field is defined using a string,
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i.e.::
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class MyModel(Model):
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fk = ForeignKey("AnotherModel")
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This string can be:
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* RECURSIVE_RELATIONSHIP_CONSTANT (i.e. "self") to indicate a recursive
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relation.
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* The name of a model (i.e "AnotherModel") to indicate another model in
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the same app.
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* An app-label and model name (i.e. "someapp.AnotherModel") to indicate
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another model in a different app.
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If the other model hasn't yet been loaded -- almost a given if you're using
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lazy relationships -- then the relation won't be set up until the
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class_prepared signal fires at the end of model initialization.
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operation is the work that must be performed once the relation can be resolved.
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"""
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# Check for recursive relations
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if relation == RECURSIVE_RELATIONSHIP_CONSTANT:
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app_label = cls._meta.app_label
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model_name = cls.__name__
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else:
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# Look for an "app.Model" relation
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if isinstance(relation, six.string_types):
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try:
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app_label, model_name = relation.split(".")
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except ValueError:
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# If we can't split, assume a model in current app
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app_label = cls._meta.app_label
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model_name = relation
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else:
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# it's actually a model class
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app_label = relation._meta.app_label
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model_name = relation._meta.object_name
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# Try to look up the related model, and if it's already loaded resolve the
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# string right away. If get_model returns None, it means that the related
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# model isn't loaded yet, so we need to pend the relation until the class
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# is prepared.
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model = get_model(app_label, model_name,
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seed_cache=False, only_installed=False)
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if model:
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operation(field, model, cls)
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else:
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key = (app_label, model_name)
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value = (cls, field, operation)
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pending_lookups.setdefault(key, []).append(value)
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def do_pending_lookups(sender, **kwargs):
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"""
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Handle any pending relations to the sending model. Sent from class_prepared.
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"""
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key = (sender._meta.app_label, sender.__name__)
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for cls, field, operation in pending_lookups.pop(key, []):
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operation(field, sender, cls)
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signals.class_prepared.connect(do_pending_lookups)
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class RelatedField(Field):
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def db_type(self, connection):
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'''By default related field will not have a column
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as it relates columns to another table'''
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return None
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def contribute_to_class(self, cls, name, virtual_only=False):
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sup = super(RelatedField, self)
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# Store the opts for related_query_name()
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self.opts = cls._meta
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if hasattr(sup, 'contribute_to_class'):
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sup.contribute_to_class(cls, name, virtual_only=virtual_only)
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if not cls._meta.abstract and self.rel.related_name:
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related_name = self.rel.related_name % {
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'class': cls.__name__.lower(),
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'app_label': cls._meta.app_label.lower()
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}
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self.rel.related_name = related_name
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other = self.rel.to
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if isinstance(other, six.string_types) or other._meta.pk is None:
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def resolve_related_class(field, model, cls):
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field.rel.to = model
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field.do_related_class(model, cls)
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add_lazy_relation(cls, self, other, resolve_related_class)
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else:
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self.do_related_class(other, cls)
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def set_attributes_from_rel(self):
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self.name = self.name or (self.rel.to._meta.model_name + '_' + self.rel.to._meta.pk.name)
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if self.verbose_name is None:
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self.verbose_name = self.rel.to._meta.verbose_name
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self.rel.set_field_name()
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def do_related_class(self, other, cls):
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self.set_attributes_from_rel()
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self.related = RelatedObject(other, cls, self)
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if not cls._meta.abstract:
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self.contribute_to_related_class(other, self.related)
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def related_query_name(self):
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# This method defines the name that can be used to identify this
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# related object in a table-spanning query. It uses the lower-cased
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# object_name by default, but this can be overridden with the
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# "related_name" option.
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return self.rel.related_query_name or self.rel.related_name or self.opts.model_name
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class RenameRelatedObjectDescriptorMethods(RenameMethodsBase):
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renamed_methods = (
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('get_query_set', 'get_queryset', DeprecationWarning),
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('get_prefetch_query_set', 'get_prefetch_queryset', DeprecationWarning),
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)
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class SingleRelatedObjectDescriptor(six.with_metaclass(RenameRelatedObjectDescriptorMethods)):
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# This class provides the functionality that makes the related-object
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# managers available as attributes on a model class, for fields that have
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# a single "remote" value, on the class pointed to by a related field.
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# In the example "place.restaurant", the restaurant attribute is a
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# SingleRelatedObjectDescriptor instance.
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def __init__(self, related):
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self.related = related
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self.cache_name = related.get_cache_name()
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def is_cached(self, instance):
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return hasattr(instance, self.cache_name)
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def get_queryset(self, **db_hints):
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db = router.db_for_read(self.related.model, **db_hints)
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return self.related.model._base_manager.using(db)
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def get_prefetch_queryset(self, instances):
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rel_obj_attr = attrgetter(self.related.field.attname)
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instance_attr = lambda obj: obj._get_pk_val()
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instances_dict = dict((instance_attr(inst), inst) for inst in instances)
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query = {'%s__in' % self.related.field.name: instances}
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qs = self.get_queryset(instance=instances[0]).filter(**query)
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# Since we're going to assign directly in the cache,
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# we must manage the reverse relation cache manually.
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rel_obj_cache_name = self.related.field.get_cache_name()
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for rel_obj in qs:
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instance = instances_dict[rel_obj_attr(rel_obj)]
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setattr(rel_obj, rel_obj_cache_name, instance)
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return qs, rel_obj_attr, instance_attr, True, self.cache_name
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def __get__(self, instance, instance_type=None):
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if instance is None:
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return self
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try:
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rel_obj = getattr(instance, self.cache_name)
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except AttributeError:
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related_pk = instance._get_pk_val()
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if related_pk is None:
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rel_obj = None
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else:
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params = {}
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for lh_field, rh_field in self.related.field.related_fields:
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params['%s__%s' % (self.related.field.name, rh_field.name)] = getattr(instance, rh_field.attname)
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try:
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rel_obj = self.get_queryset(instance=instance).get(**params)
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except self.related.model.DoesNotExist:
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rel_obj = None
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else:
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setattr(rel_obj, self.related.field.get_cache_name(), instance)
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setattr(instance, self.cache_name, rel_obj)
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if rel_obj is None:
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raise self.related.model.DoesNotExist("%s has no %s." % (
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instance.__class__.__name__,
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self.related.get_accessor_name()))
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else:
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return rel_obj
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def __set__(self, instance, value):
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# The similarity of the code below to the code in
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# ReverseSingleRelatedObjectDescriptor is annoying, but there's a bunch
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# of small differences that would make a common base class convoluted.
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# If null=True, we can assign null here, but otherwise the value needs
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# to be an instance of the related class.
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if value is None and self.related.field.null is False:
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raise ValueError('Cannot assign None: "%s.%s" does not allow null values.' %
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(instance._meta.object_name, self.related.get_accessor_name()))
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elif value is not None and not isinstance(value, self.related.model):
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raise ValueError('Cannot assign "%r": "%s.%s" must be a "%s" instance.' %
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(value, instance._meta.object_name,
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self.related.get_accessor_name(), self.related.opts.object_name))
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elif value is not None:
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if instance._state.db is None:
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instance._state.db = router.db_for_write(instance.__class__, instance=value)
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elif value._state.db is None:
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value._state.db = router.db_for_write(value.__class__, instance=instance)
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elif value._state.db is not None and instance._state.db is not None:
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if not router.allow_relation(value, instance):
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raise ValueError('Cannot assign "%r": the current database router prevents this relation.' % value)
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related_pk = tuple([getattr(instance, field.attname) for field in self.related.field.foreign_related_fields])
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if None in related_pk:
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raise ValueError('Cannot assign "%r": "%s" instance isn\'t saved in the database.' %
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(value, instance._meta.object_name))
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# Set the value of the related field to the value of the related object's related field
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for index, field in enumerate(self.related.field.local_related_fields):
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setattr(value, field.attname, related_pk[index])
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# Since we already know what the related object is, seed the related
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# object caches now, too. This avoids another db hit if you get the
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# object you just set.
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setattr(instance, self.cache_name, value)
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setattr(value, self.related.field.get_cache_name(), instance)
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class ReverseSingleRelatedObjectDescriptor(six.with_metaclass(RenameRelatedObjectDescriptorMethods)):
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# This class provides the functionality that makes the related-object
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# managers available as attributes on a model class, for fields that have
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# a single "remote" value, on the class that defines the related field.
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# In the example "choice.poll", the poll attribute is a
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# ReverseSingleRelatedObjectDescriptor instance.
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def __init__(self, field_with_rel):
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self.field = field_with_rel
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self.cache_name = self.field.get_cache_name()
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def is_cached(self, instance):
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return hasattr(instance, self.cache_name)
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def get_queryset(self, **db_hints):
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db = router.db_for_read(self.field.rel.to, **db_hints)
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rel_mgr = self.field.rel.to._default_manager
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# If the related manager indicates that it should be used for
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# related fields, respect that.
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if getattr(rel_mgr, 'use_for_related_fields', False):
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return rel_mgr.using(db)
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else:
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return QuerySet(self.field.rel.to).using(db)
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def get_prefetch_queryset(self, instances):
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rel_obj_attr = self.field.get_foreign_related_value
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instance_attr = self.field.get_local_related_value
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instances_dict = dict((instance_attr(inst), inst) for inst in instances)
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query = {'%s__in' % self.field.related_query_name(): instances}
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qs = self.get_queryset(instance=instances[0]).filter(**query)
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# Since we're going to assign directly in the cache,
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# we must manage the reverse relation cache manually.
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if not self.field.rel.multiple:
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rel_obj_cache_name = self.field.related.get_cache_name()
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for rel_obj in qs:
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instance = instances_dict[rel_obj_attr(rel_obj)]
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setattr(rel_obj, rel_obj_cache_name, instance)
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return qs, rel_obj_attr, instance_attr, True, self.cache_name
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def __get__(self, instance, instance_type=None):
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if instance is None:
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return self
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try:
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rel_obj = getattr(instance, self.cache_name)
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except AttributeError:
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val = self.field.get_local_related_value(instance)
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if None in val:
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rel_obj = None
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else:
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params = dict(
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(rh_field.attname, getattr(instance, lh_field.attname))
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for lh_field, rh_field in self.field.related_fields)
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qs = self.get_queryset(instance=instance)
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extra_filter = self.field.get_extra_descriptor_filter(instance)
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if isinstance(extra_filter, dict):
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params.update(extra_filter)
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qs = qs.filter(**params)
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else:
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qs = qs.filter(extra_filter, **params)
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# Assuming the database enforces foreign keys, this won't fail.
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rel_obj = qs.get()
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if not self.field.rel.multiple:
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setattr(rel_obj, self.field.related.get_cache_name(), instance)
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setattr(instance, self.cache_name, rel_obj)
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if rel_obj is None and not self.field.null:
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raise self.field.rel.to.DoesNotExist(
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"%s has no %s." % (self.field.model.__name__, self.field.name))
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else:
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return rel_obj
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def __set__(self, instance, value):
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# If null=True, we can assign null here, but otherwise the value needs
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# to be an instance of the related class.
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if value is None and self.field.null is False:
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raise ValueError('Cannot assign None: "%s.%s" does not allow null values.' %
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(instance._meta.object_name, self.field.name))
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elif value is not None and not isinstance(value, self.field.rel.to):
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raise ValueError('Cannot assign "%r": "%s.%s" must be a "%s" instance.' %
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(value, instance._meta.object_name,
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self.field.name, self.field.rel.to._meta.object_name))
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elif value is not None:
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if instance._state.db is None:
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instance._state.db = router.db_for_write(instance.__class__, instance=value)
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elif value._state.db is None:
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value._state.db = router.db_for_write(value.__class__, instance=instance)
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elif value._state.db is not None and instance._state.db is not None:
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if not router.allow_relation(value, instance):
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raise ValueError('Cannot assign "%r": the current database router prevents this relation.' % value)
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# If we're setting the value of a OneToOneField to None, we need to clear
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# out the cache on any old related object. Otherwise, deleting the
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# previously-related object will also cause this object to be deleted,
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# which is wrong.
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if value is None:
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# Look up the previously-related object, which may still be available
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# since we've not yet cleared out the related field.
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# Use the cache directly, instead of the accessor; if we haven't
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# populated the cache, then we don't care - we're only accessing
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# the object to invalidate the accessor cache, so there's no
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# need to populate the cache just to expire it again.
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related = getattr(instance, self.cache_name, None)
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# If we've got an old related object, we need to clear out its
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# cache. This cache also might not exist if the related object
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# hasn't been accessed yet.
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if related is not None:
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setattr(related, self.field.related.get_cache_name(), None)
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# Set the value of the related field
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for lh_field, rh_field in self.field.related_fields:
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try:
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setattr(instance, lh_field.attname, getattr(value, rh_field.attname))
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except AttributeError:
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setattr(instance, lh_field.attname, None)
|
|
|
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# Since we already know what the related object is, seed the related
|
|
# object caches now, too. This avoids another db hit if you get the
|
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# object you just set.
|
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setattr(instance, self.cache_name, value)
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if value is not None and not self.field.rel.multiple:
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setattr(value, self.field.related.get_cache_name(), instance)
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|
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class ForeignRelatedObjectsDescriptor(object):
|
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# This class provides the functionality that makes the related-object
|
|
# managers available as attributes on a model class, for fields that have
|
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# multiple "remote" values and have a ForeignKey pointed at them by
|
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# some other model. In the example "poll.choice_set", the choice_set
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# attribute is a ForeignRelatedObjectsDescriptor instance.
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def __init__(self, related):
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self.related = related # RelatedObject instance
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def __get__(self, instance, instance_type=None):
|
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if instance is None:
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return self
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|
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return self.related_manager_cls(instance)
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|
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def __set__(self, instance, value):
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manager = self.__get__(instance)
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# If the foreign key can support nulls, then completely clear the related set.
|
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# Otherwise, just move the named objects into the set.
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if self.related.field.null:
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manager.clear()
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manager.add(*value)
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|
|
@cached_property
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def related_manager_cls(self):
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# Dynamically create a class that subclasses the related model's default
|
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# manager.
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superclass = self.related.model._default_manager.__class__
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rel_field = self.related.field
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rel_model = self.related.model
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class RelatedManager(superclass):
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def __init__(self, instance):
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super(RelatedManager, self).__init__()
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self.instance = instance
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self.core_filters = {'%s__exact' % rel_field.name: instance}
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self.model = rel_model
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def get_queryset(self):
|
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try:
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return self.instance._prefetched_objects_cache[rel_field.related_query_name()]
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except (AttributeError, KeyError):
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db = self._db or router.db_for_read(self.model, instance=self.instance)
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qs = super(RelatedManager, self).get_queryset().using(db).filter(**self.core_filters)
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empty_strings_as_null = connections[db].features.interprets_empty_strings_as_nulls
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for field in rel_field.foreign_related_fields:
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val = getattr(self.instance, field.attname)
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if val is None or (val == '' and empty_strings_as_null):
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return qs.none()
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qs._known_related_objects = {rel_field: {self.instance.pk: self.instance}}
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return qs
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|
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def get_prefetch_queryset(self, instances):
|
|
rel_obj_attr = rel_field.get_local_related_value
|
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instance_attr = rel_field.get_foreign_related_value
|
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instances_dict = dict((instance_attr(inst), inst) for inst in instances)
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db = self._db or router.db_for_read(self.model, instance=instances[0])
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query = {'%s__in' % rel_field.name: instances}
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qs = super(RelatedManager, self).get_queryset().using(db).filter(**query)
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# Since we just bypassed this class' get_queryset(), we must manage
|
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# the reverse relation manually.
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for rel_obj in qs:
|
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instance = instances_dict[rel_obj_attr(rel_obj)]
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setattr(rel_obj, rel_field.name, instance)
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cache_name = rel_field.related_query_name()
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return qs, rel_obj_attr, instance_attr, False, cache_name
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|
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def add(self, *objs):
|
|
for obj in objs:
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|
if not isinstance(obj, self.model):
|
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raise TypeError("'%s' instance expected, got %r" % (self.model._meta.object_name, obj))
|
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setattr(obj, rel_field.name, self.instance)
|
|
obj.save()
|
|
add.alters_data = True
|
|
|
|
def create(self, **kwargs):
|
|
kwargs[rel_field.name] = self.instance
|
|
db = router.db_for_write(self.model, instance=self.instance)
|
|
return super(RelatedManager, self.db_manager(db)).create(**kwargs)
|
|
create.alters_data = True
|
|
|
|
def get_or_create(self, **kwargs):
|
|
# Update kwargs with the related object that this
|
|
# ForeignRelatedObjectsDescriptor knows about.
|
|
kwargs[rel_field.name] = self.instance
|
|
db = router.db_for_write(self.model, instance=self.instance)
|
|
return super(RelatedManager, self.db_manager(db)).get_or_create(**kwargs)
|
|
get_or_create.alters_data = True
|
|
|
|
# remove() and clear() are only provided if the ForeignKey can have a value of null.
|
|
if rel_field.null:
|
|
def remove(self, *objs):
|
|
val = rel_field.get_foreign_related_value(self.instance)
|
|
for obj in objs:
|
|
# Is obj actually part of this descriptor set?
|
|
if rel_field.get_local_related_value(obj) == val:
|
|
setattr(obj, rel_field.name, None)
|
|
obj.save()
|
|
else:
|
|
raise rel_field.rel.to.DoesNotExist("%r is not related to %r." % (obj, self.instance))
|
|
remove.alters_data = True
|
|
|
|
def clear(self):
|
|
self.update(**{rel_field.name: None})
|
|
clear.alters_data = True
|
|
|
|
return RelatedManager
|
|
|
|
|
|
def create_many_related_manager(superclass, rel):
|
|
"""Creates a manager that subclasses 'superclass' (which is a Manager)
|
|
and adds behavior for many-to-many related objects."""
|
|
class ManyRelatedManager(superclass):
|
|
def __init__(self, model=None, query_field_name=None, instance=None, symmetrical=None,
|
|
source_field_name=None, target_field_name=None, reverse=False,
|
|
through=None, prefetch_cache_name=None):
|
|
super(ManyRelatedManager, self).__init__()
|
|
self.model = model
|
|
self.query_field_name = query_field_name
|
|
|
|
source_field = through._meta.get_field(source_field_name)
|
|
source_related_fields = source_field.related_fields
|
|
|
|
self.core_filters = {}
|
|
for lh_field, rh_field in source_related_fields:
|
|
self.core_filters['%s__%s' % (query_field_name, rh_field.name)] = getattr(instance, rh_field.attname)
|
|
|
|
self.instance = instance
|
|
self.symmetrical = symmetrical
|
|
self.source_field = source_field
|
|
self.source_field_name = source_field_name
|
|
self.target_field_name = target_field_name
|
|
self.reverse = reverse
|
|
self.through = through
|
|
self.prefetch_cache_name = prefetch_cache_name
|
|
self.related_val = source_field.get_foreign_related_value(instance)
|
|
# Used for single column related auto created models
|
|
self._fk_val = self.related_val[0]
|
|
if None in self.related_val:
|
|
raise ValueError('"%r" needs to have a value for field "%s" before '
|
|
'this many-to-many relationship can be used.' %
|
|
(instance, source_field_name))
|
|
# Even if this relation is not to pk, we require still pk value.
|
|
# The wish is that the instance has been already saved to DB,
|
|
# although having a pk value isn't a guarantee of that.
|
|
if instance.pk is None:
|
|
raise ValueError("%r instance needs to have a primary key value before "
|
|
"a many-to-many relationship can be used." %
|
|
instance.__class__.__name__)
|
|
|
|
def _get_fk_val(self, obj, field_name):
|
|
"""
|
|
Returns the correct value for this relationship's foreign key. This
|
|
might be something else than pk value when to_field is used.
|
|
"""
|
|
fk = self.through._meta.get_field(field_name)
|
|
if fk.rel.field_name and fk.rel.field_name != fk.rel.to._meta.pk.attname:
|
|
attname = fk.rel.get_related_field().get_attname()
|
|
return fk.get_prep_lookup('exact', getattr(obj, attname))
|
|
else:
|
|
return obj.pk
|
|
|
|
def get_queryset(self):
|
|
try:
|
|
return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
|
|
except (AttributeError, KeyError):
|
|
db = self._db or router.db_for_read(self.instance.__class__, instance=self.instance)
|
|
return super(ManyRelatedManager, self).get_queryset().using(db)._next_is_sticky().filter(**self.core_filters)
|
|
|
|
def get_prefetch_queryset(self, instances):
|
|
instance = instances[0]
|
|
db = self._db or router.db_for_read(instance.__class__, instance=instance)
|
|
query = {'%s__in' % self.query_field_name: instances}
|
|
qs = super(ManyRelatedManager, self).get_queryset().using(db)._next_is_sticky().filter(**query)
|
|
|
|
# M2M: need to annotate the query in order to get the primary model
|
|
# that the secondary model was actually related to. We know that
|
|
# there will already be a join on the join table, so we can just add
|
|
# the select.
|
|
|
|
# For non-autocreated 'through' models, can't assume we are
|
|
# dealing with PK values.
|
|
fk = self.through._meta.get_field(self.source_field_name)
|
|
join_table = self.through._meta.db_table
|
|
connection = connections[db]
|
|
qn = connection.ops.quote_name
|
|
qs = qs.extra(select=dict(
|
|
('_prefetch_related_val_%s' % f.attname,
|
|
'%s.%s' % (qn(join_table), qn(f.column))) for f in fk.local_related_fields))
|
|
return (qs,
|
|
lambda result: tuple([getattr(result, '_prefetch_related_val_%s' % f.attname) for f in fk.local_related_fields]),
|
|
lambda inst: tuple([getattr(inst, f.attname) for f in fk.foreign_related_fields]),
|
|
False,
|
|
self.prefetch_cache_name)
|
|
|
|
# If the ManyToMany relation has an intermediary model,
|
|
# the add and remove methods do not exist.
|
|
if rel.through._meta.auto_created:
|
|
def add(self, *objs):
|
|
self._add_items(self.source_field_name, self.target_field_name, *objs)
|
|
|
|
# If this is a symmetrical m2m relation to self, add the mirror entry in the m2m table
|
|
if self.symmetrical:
|
|
self._add_items(self.target_field_name, self.source_field_name, *objs)
|
|
add.alters_data = True
|
|
|
|
def remove(self, *objs):
|
|
self._remove_items(self.source_field_name, self.target_field_name, *objs)
|
|
|
|
# If this is a symmetrical m2m relation to self, remove the mirror entry in the m2m table
|
|
if self.symmetrical:
|
|
self._remove_items(self.target_field_name, self.source_field_name, *objs)
|
|
remove.alters_data = True
|
|
|
|
def clear(self):
|
|
self._clear_items(self.source_field_name)
|
|
|
|
# If this is a symmetrical m2m relation to self, clear the mirror entry in the m2m table
|
|
if self.symmetrical:
|
|
self._clear_items(self.target_field_name)
|
|
clear.alters_data = True
|
|
|
|
def create(self, **kwargs):
|
|
# This check needs to be done here, since we can't later remove this
|
|
# from the method lookup table, as we do with add and remove.
|
|
if not self.through._meta.auto_created:
|
|
opts = self.through._meta
|
|
raise AttributeError("Cannot use create() on a ManyToManyField which specifies an intermediary model. Use %s.%s's Manager instead." % (opts.app_label, opts.object_name))
|
|
db = router.db_for_write(self.instance.__class__, instance=self.instance)
|
|
new_obj = super(ManyRelatedManager, self.db_manager(db)).create(**kwargs)
|
|
self.add(new_obj)
|
|
return new_obj
|
|
create.alters_data = True
|
|
|
|
def get_or_create(self, **kwargs):
|
|
db = router.db_for_write(self.instance.__class__, instance=self.instance)
|
|
obj, created = \
|
|
super(ManyRelatedManager, self.db_manager(db)).get_or_create(**kwargs)
|
|
# We only need to add() if created because if we got an object back
|
|
# from get() then the relationship already exists.
|
|
if created:
|
|
self.add(obj)
|
|
return obj, created
|
|
get_or_create.alters_data = True
|
|
|
|
def _add_items(self, source_field_name, target_field_name, *objs):
|
|
# source_field_name: the PK fieldname in join table for the source object
|
|
# target_field_name: the PK fieldname in join table for the target object
|
|
# *objs - objects to add. Either object instances, or primary keys of object instances.
|
|
|
|
# If there aren't any objects, there is nothing to do.
|
|
from django.db.models import Model
|
|
if objs:
|
|
new_ids = set()
|
|
for obj in objs:
|
|
if isinstance(obj, self.model):
|
|
if not router.allow_relation(obj, self.instance):
|
|
raise ValueError('Cannot add "%r": instance is on database "%s", value is on database "%s"' %
|
|
(obj, self.instance._state.db, obj._state.db))
|
|
fk_val = self._get_fk_val(obj, target_field_name)
|
|
if fk_val is None:
|
|
raise ValueError('Cannot add "%r": the value for field "%s" is None' %
|
|
(obj, target_field_name))
|
|
new_ids.add(self._get_fk_val(obj, target_field_name))
|
|
elif isinstance(obj, Model):
|
|
raise TypeError("'%s' instance expected, got %r" % (self.model._meta.object_name, obj))
|
|
else:
|
|
new_ids.add(obj)
|
|
db = router.db_for_write(self.through, instance=self.instance)
|
|
vals = self.through._default_manager.using(db).values_list(target_field_name, flat=True)
|
|
vals = vals.filter(**{
|
|
source_field_name: self._fk_val,
|
|
'%s__in' % target_field_name: new_ids,
|
|
})
|
|
new_ids = new_ids - set(vals)
|
|
|
|
if self.reverse or source_field_name == self.source_field_name:
|
|
# Don't send the signal when we are inserting the
|
|
# duplicate data row for symmetrical reverse entries.
|
|
signals.m2m_changed.send(sender=self.through, action='pre_add',
|
|
instance=self.instance, reverse=self.reverse,
|
|
model=self.model, pk_set=new_ids, using=db)
|
|
# Add the ones that aren't there already
|
|
self.through._default_manager.using(db).bulk_create([
|
|
self.through(**{
|
|
'%s_id' % source_field_name: self._fk_val,
|
|
'%s_id' % target_field_name: obj_id,
|
|
})
|
|
for obj_id in new_ids
|
|
])
|
|
|
|
if self.reverse or source_field_name == self.source_field_name:
|
|
# Don't send the signal when we are inserting the
|
|
# duplicate data row for symmetrical reverse entries.
|
|
signals.m2m_changed.send(sender=self.through, action='post_add',
|
|
instance=self.instance, reverse=self.reverse,
|
|
model=self.model, pk_set=new_ids, using=db)
|
|
|
|
def _remove_items(self, source_field_name, target_field_name, *objs):
|
|
# source_field_name: the PK colname in join table for the source object
|
|
# target_field_name: the PK colname in join table for the target object
|
|
# *objs - objects to remove
|
|
|
|
# If there aren't any objects, there is nothing to do.
|
|
if objs:
|
|
# Check that all the objects are of the right type
|
|
old_ids = set()
|
|
for obj in objs:
|
|
if isinstance(obj, self.model):
|
|
old_ids.add(self._get_fk_val(obj, target_field_name))
|
|
else:
|
|
old_ids.add(obj)
|
|
# Work out what DB we're operating on
|
|
db = router.db_for_write(self.through, instance=self.instance)
|
|
# Send a signal to the other end if need be.
|
|
if self.reverse or source_field_name == self.source_field_name:
|
|
# Don't send the signal when we are deleting the
|
|
# duplicate data row for symmetrical reverse entries.
|
|
signals.m2m_changed.send(sender=self.through, action="pre_remove",
|
|
instance=self.instance, reverse=self.reverse,
|
|
model=self.model, pk_set=old_ids, using=db)
|
|
# Remove the specified objects from the join table
|
|
self.through._default_manager.using(db).filter(**{
|
|
source_field_name: self._fk_val,
|
|
'%s__in' % target_field_name: old_ids
|
|
}).delete()
|
|
if self.reverse or source_field_name == self.source_field_name:
|
|
# Don't send the signal when we are deleting the
|
|
# duplicate data row for symmetrical reverse entries.
|
|
signals.m2m_changed.send(sender=self.through, action="post_remove",
|
|
instance=self.instance, reverse=self.reverse,
|
|
model=self.model, pk_set=old_ids, using=db)
|
|
|
|
def _clear_items(self, source_field_name):
|
|
db = router.db_for_write(self.through, instance=self.instance)
|
|
# source_field_name: the PK colname in join table for the source object
|
|
if self.reverse or source_field_name == self.source_field_name:
|
|
# Don't send the signal when we are clearing the
|
|
# duplicate data rows for symmetrical reverse entries.
|
|
signals.m2m_changed.send(sender=self.through, action="pre_clear",
|
|
instance=self.instance, reverse=self.reverse,
|
|
model=self.model, pk_set=None, using=db)
|
|
self.through._default_manager.using(db).filter(**{
|
|
source_field_name: self.related_val
|
|
}).delete()
|
|
if self.reverse or source_field_name == self.source_field_name:
|
|
# Don't send the signal when we are clearing the
|
|
# duplicate data rows for symmetrical reverse entries.
|
|
signals.m2m_changed.send(sender=self.through, action="post_clear",
|
|
instance=self.instance, reverse=self.reverse,
|
|
model=self.model, pk_set=None, using=db)
|
|
|
|
return ManyRelatedManager
|
|
|
|
|
|
class ManyRelatedObjectsDescriptor(object):
|
|
# This class provides the functionality that makes the related-object
|
|
# managers available as attributes on a model class, for fields that have
|
|
# multiple "remote" values and have a ManyToManyField pointed at them by
|
|
# some other model (rather than having a ManyToManyField themselves).
|
|
# In the example "publication.article_set", the article_set attribute is a
|
|
# ManyRelatedObjectsDescriptor instance.
|
|
def __init__(self, related):
|
|
self.related = related # RelatedObject instance
|
|
|
|
@cached_property
|
|
def related_manager_cls(self):
|
|
# Dynamically create a class that subclasses the related
|
|
# model's default manager.
|
|
return create_many_related_manager(
|
|
self.related.model._default_manager.__class__,
|
|
self.related.field.rel
|
|
)
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
rel_model = self.related.model
|
|
|
|
manager = self.related_manager_cls(
|
|
model=rel_model,
|
|
query_field_name=self.related.field.name,
|
|
prefetch_cache_name=self.related.field.related_query_name(),
|
|
instance=instance,
|
|
symmetrical=False,
|
|
source_field_name=self.related.field.m2m_reverse_field_name(),
|
|
target_field_name=self.related.field.m2m_field_name(),
|
|
reverse=True,
|
|
through=self.related.field.rel.through,
|
|
)
|
|
|
|
return manager
|
|
|
|
def __set__(self, instance, value):
|
|
if not self.related.field.rel.through._meta.auto_created:
|
|
opts = self.related.field.rel.through._meta
|
|
raise AttributeError("Cannot set values on a ManyToManyField which specifies an intermediary model. Use %s.%s's Manager instead." % (opts.app_label, opts.object_name))
|
|
|
|
manager = self.__get__(instance)
|
|
manager.clear()
|
|
manager.add(*value)
|
|
|
|
|
|
class ReverseManyRelatedObjectsDescriptor(object):
|
|
# This class provides the functionality that makes the related-object
|
|
# managers available as attributes on a model class, for fields that have
|
|
# multiple "remote" values and have a ManyToManyField defined in their
|
|
# model (rather than having another model pointed *at* them).
|
|
# In the example "article.publications", the publications attribute is a
|
|
# ReverseManyRelatedObjectsDescriptor instance.
|
|
def __init__(self, m2m_field):
|
|
self.field = m2m_field
|
|
|
|
@property
|
|
def through(self):
|
|
# through is provided so that you have easy access to the through
|
|
# model (Book.authors.through) for inlines, etc. This is done as
|
|
# a property to ensure that the fully resolved value is returned.
|
|
return self.field.rel.through
|
|
|
|
@cached_property
|
|
def related_manager_cls(self):
|
|
# Dynamically create a class that subclasses the related model's
|
|
# default manager.
|
|
return create_many_related_manager(
|
|
self.field.rel.to._default_manager.__class__,
|
|
self.field.rel
|
|
)
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
manager = self.related_manager_cls(
|
|
model=self.field.rel.to,
|
|
query_field_name=self.field.related_query_name(),
|
|
prefetch_cache_name=self.field.name,
|
|
instance=instance,
|
|
symmetrical=self.field.rel.symmetrical,
|
|
source_field_name=self.field.m2m_field_name(),
|
|
target_field_name=self.field.m2m_reverse_field_name(),
|
|
reverse=False,
|
|
through=self.field.rel.through,
|
|
)
|
|
|
|
return manager
|
|
|
|
def __set__(self, instance, value):
|
|
if not self.field.rel.through._meta.auto_created:
|
|
opts = self.field.rel.through._meta
|
|
raise AttributeError("Cannot set values on a ManyToManyField which specifies an intermediary model. Use %s.%s's Manager instead." % (opts.app_label, opts.object_name))
|
|
|
|
manager = self.__get__(instance)
|
|
# clear() can change expected output of 'value' queryset, we force evaluation
|
|
# of queryset before clear; ticket #19816
|
|
value = tuple(value)
|
|
manager.clear()
|
|
manager.add(*value)
|
|
|
|
|
|
class ForeignObjectRel(object):
|
|
def __init__(self, field, to, related_name=None, limit_choices_to=None,
|
|
parent_link=False, on_delete=None, related_query_name=None):
|
|
try:
|
|
to._meta
|
|
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
|
|
assert isinstance(to, six.string_types), "'to' must be either a model, a model name or the string %r" % RECURSIVE_RELATIONSHIP_CONSTANT
|
|
|
|
self.field = field
|
|
self.to = to
|
|
self.related_name = related_name
|
|
self.related_query_name = related_query_name
|
|
self.limit_choices_to = {} if limit_choices_to is None else limit_choices_to
|
|
self.multiple = True
|
|
self.parent_link = parent_link
|
|
self.on_delete = on_delete
|
|
|
|
def is_hidden(self):
|
|
"Should the related object be hidden?"
|
|
return self.related_name and self.related_name[-1] == '+'
|
|
|
|
def get_joining_columns(self):
|
|
return self.field.get_reverse_joining_columns()
|
|
|
|
def get_extra_restriction(self, where_class, alias, related_alias):
|
|
return self.field.get_extra_restriction(where_class, related_alias, alias)
|
|
|
|
def set_field_name(self):
|
|
"""
|
|
Sets the related field's name, this is not available until later stages
|
|
of app loading, so set_field_name is called from
|
|
set_attributes_from_rel()
|
|
"""
|
|
# By default foreign object doesn't relate to any remote field (for
|
|
# example custom multicolumn joins currently have no remote field).
|
|
self.field_name = None
|
|
|
|
|
|
class ManyToOneRel(ForeignObjectRel):
|
|
def __init__(self, field, to, field_name, related_name=None, limit_choices_to=None,
|
|
parent_link=False, on_delete=None, related_query_name=None):
|
|
super(ManyToOneRel, self).__init__(
|
|
field, to, related_name=related_name, limit_choices_to=limit_choices_to,
|
|
parent_link=parent_link, on_delete=on_delete, related_query_name=related_query_name)
|
|
self.field_name = field_name
|
|
|
|
def get_related_field(self):
|
|
"""
|
|
Returns the Field in the 'to' object to which this relationship is
|
|
tied.
|
|
"""
|
|
data = self.to._meta.get_field_by_name(self.field_name)
|
|
if not data[2]:
|
|
raise FieldDoesNotExist("No related field named '%s'" %
|
|
self.field_name)
|
|
return data[0]
|
|
|
|
def set_field_name(self):
|
|
self.field_name = self.field_name or self.to._meta.pk.name
|
|
|
|
|
|
class OneToOneRel(ManyToOneRel):
|
|
def __init__(self, field, to, field_name, related_name=None, limit_choices_to=None,
|
|
parent_link=False, on_delete=None, related_query_name=None):
|
|
super(OneToOneRel, self).__init__(field, to, field_name,
|
|
related_name=related_name, limit_choices_to=limit_choices_to,
|
|
parent_link=parent_link, on_delete=on_delete, related_query_name=related_query_name,
|
|
)
|
|
self.multiple = False
|
|
|
|
|
|
class ManyToManyRel(object):
|
|
def __init__(self, to, related_name=None, limit_choices_to=None,
|
|
symmetrical=True, through=None, db_constraint=True, related_query_name=None):
|
|
if through and not db_constraint:
|
|
raise ValueError("Can't supply a through model and db_constraint=False")
|
|
self.to = to
|
|
self.related_name = related_name
|
|
self.related_query_name = related_query_name
|
|
if limit_choices_to is None:
|
|
limit_choices_to = {}
|
|
self.limit_choices_to = limit_choices_to
|
|
self.symmetrical = symmetrical
|
|
self.multiple = True
|
|
self.through = through
|
|
self.db_constraint = db_constraint
|
|
|
|
def is_hidden(self):
|
|
"Should the related object be hidden?"
|
|
return self.related_name and self.related_name[-1] == '+'
|
|
|
|
def get_related_field(self):
|
|
"""
|
|
Returns the field in the to' object to which this relationship is tied
|
|
(this is always the primary key on the target model). Provided for
|
|
symmetry with ManyToOneRel.
|
|
"""
|
|
return self.to._meta.pk
|
|
|
|
|
|
class ForeignObject(RelatedField):
|
|
requires_unique_target = True
|
|
generate_reverse_relation = True
|
|
|
|
def __init__(self, to, from_fields, to_fields, **kwargs):
|
|
self.from_fields = from_fields
|
|
self.to_fields = to_fields
|
|
|
|
if 'rel' not in kwargs:
|
|
kwargs['rel'] = ForeignObjectRel(
|
|
self, to,
|
|
related_name=kwargs.pop('related_name', None),
|
|
related_query_name=kwargs.pop('related_query_name', None),
|
|
limit_choices_to=kwargs.pop('limit_choices_to', None),
|
|
parent_link=kwargs.pop('parent_link', False),
|
|
on_delete=kwargs.pop('on_delete', CASCADE),
|
|
)
|
|
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
|
|
|
|
super(ForeignObject, self).__init__(**kwargs)
|
|
|
|
def resolve_related_fields(self):
|
|
if len(self.from_fields) < 1 or len(self.from_fields) != len(self.to_fields):
|
|
raise ValueError('Foreign Object from and to fields must be the same non-zero length')
|
|
related_fields = []
|
|
for index in range(len(self.from_fields)):
|
|
from_field_name = self.from_fields[index]
|
|
to_field_name = self.to_fields[index]
|
|
from_field = (self if from_field_name == 'self'
|
|
else self.opts.get_field_by_name(from_field_name)[0])
|
|
to_field = (self.rel.to._meta.pk if to_field_name is None
|
|
else self.rel.to._meta.get_field_by_name(to_field_name)[0])
|
|
related_fields.append((from_field, to_field))
|
|
return related_fields
|
|
|
|
@property
|
|
def related_fields(self):
|
|
if not hasattr(self, '_related_fields'):
|
|
self._related_fields = self.resolve_related_fields()
|
|
return self._related_fields
|
|
|
|
@property
|
|
def reverse_related_fields(self):
|
|
return [(rhs_field, lhs_field) for lhs_field, rhs_field in self.related_fields]
|
|
|
|
@property
|
|
def local_related_fields(self):
|
|
return tuple([lhs_field for lhs_field, rhs_field in self.related_fields])
|
|
|
|
@property
|
|
def foreign_related_fields(self):
|
|
return tuple([rhs_field for lhs_field, rhs_field in self.related_fields])
|
|
|
|
def get_local_related_value(self, instance):
|
|
return self.get_instance_value_for_fields(instance, self.local_related_fields)
|
|
|
|
def get_foreign_related_value(self, instance):
|
|
return self.get_instance_value_for_fields(instance, self.foreign_related_fields)
|
|
|
|
@staticmethod
|
|
def get_instance_value_for_fields(instance, fields):
|
|
return tuple([getattr(instance, field.attname) for field in fields])
|
|
|
|
def get_attname_column(self):
|
|
attname, column = super(ForeignObject, self).get_attname_column()
|
|
return attname, None
|
|
|
|
def get_joining_columns(self, reverse_join=False):
|
|
source = self.reverse_related_fields if reverse_join else self.related_fields
|
|
return tuple([(lhs_field.column, rhs_field.column) for lhs_field, rhs_field in source])
|
|
|
|
def get_reverse_joining_columns(self):
|
|
return self.get_joining_columns(reverse_join=True)
|
|
|
|
def get_extra_descriptor_filter(self, instance):
|
|
"""
|
|
Returns an extra filter condition for related object fetching when
|
|
user does 'instance.fieldname', that is the extra filter is used in
|
|
the descriptor of the field.
|
|
|
|
The filter should be either a dict usable in .filter(**kwargs) call or
|
|
a Q-object. The condition will be ANDed together with the relation's
|
|
joining columns.
|
|
|
|
A parallel method is get_extra_restriction() which is used in
|
|
JOIN and subquery conditions.
|
|
"""
|
|
return {}
|
|
|
|
def get_extra_restriction(self, where_class, alias, related_alias):
|
|
"""
|
|
Returns a pair condition used for joining and subquery pushdown. The
|
|
condition is something that responds to as_sql(qn, connection) method.
|
|
|
|
Note that currently referring both the 'alias' and 'related_alias'
|
|
will not work in some conditions, like subquery pushdown.
|
|
|
|
A parallel method is get_extra_descriptor_filter() which is used in
|
|
instance.fieldname related object fetching.
|
|
"""
|
|
return None
|
|
|
|
def get_path_info(self):
|
|
"""
|
|
Get path from this field to the related model.
|
|
"""
|
|
opts = self.rel.to._meta
|
|
from_opts = self.model._meta
|
|
return [PathInfo(from_opts, opts, self.foreign_related_fields, self, False, True)]
|
|
|
|
def get_reverse_path_info(self):
|
|
"""
|
|
Get path from the related model to this field's model.
|
|
"""
|
|
opts = self.model._meta
|
|
from_opts = self.rel.to._meta
|
|
pathinfos = [PathInfo(from_opts, opts, (opts.pk,), self.rel, not self.unique, False)]
|
|
return pathinfos
|
|
|
|
def get_lookup_constraint(self, constraint_class, alias, targets, sources, lookup_type,
|
|
raw_value):
|
|
from django.db.models.sql.where import SubqueryConstraint, Constraint, AND, OR
|
|
root_constraint = constraint_class()
|
|
assert len(targets) == len(sources)
|
|
|
|
def get_normalized_value(value):
|
|
|
|
from django.db.models import Model
|
|
if isinstance(value, Model):
|
|
value_list = []
|
|
for source in sources:
|
|
# Account for one-to-one relations when sent a different model
|
|
while not isinstance(value, source.model):
|
|
source = source.rel.to._meta.get_field(source.rel.field_name)
|
|
value_list.append(getattr(value, source.attname))
|
|
return tuple(value_list)
|
|
elif not isinstance(value, tuple):
|
|
return (value,)
|
|
return value
|
|
|
|
is_multicolumn = len(self.related_fields) > 1
|
|
if (hasattr(raw_value, '_as_sql') or
|
|
hasattr(raw_value, 'get_compiler')):
|
|
root_constraint.add(SubqueryConstraint(alias, [target.column for target in targets],
|
|
[source.name for source in sources], raw_value),
|
|
AND)
|
|
elif lookup_type == 'isnull':
|
|
root_constraint.add(
|
|
(Constraint(alias, targets[0].column, targets[0]), lookup_type, raw_value), AND)
|
|
elif (lookup_type == 'exact' or (lookup_type in ['gt', 'lt', 'gte', 'lte']
|
|
and not is_multicolumn)):
|
|
value = get_normalized_value(raw_value)
|
|
for index, source in enumerate(sources):
|
|
root_constraint.add(
|
|
(Constraint(alias, targets[index].column, sources[index]), lookup_type,
|
|
value[index]), AND)
|
|
elif lookup_type in ['range', 'in'] and not is_multicolumn:
|
|
values = [get_normalized_value(value) for value in raw_value]
|
|
value = [val[0] for val in values]
|
|
root_constraint.add(
|
|
(Constraint(alias, targets[0].column, sources[0]), lookup_type, value), AND)
|
|
elif lookup_type == 'in':
|
|
values = [get_normalized_value(value) for value in raw_value]
|
|
for value in values:
|
|
value_constraint = constraint_class()
|
|
for index, target in enumerate(targets):
|
|
value_constraint.add(
|
|
(Constraint(alias, target.column, sources[index]), 'exact', value[index]),
|
|
AND)
|
|
root_constraint.add(value_constraint, OR)
|
|
else:
|
|
raise TypeError('Related Field got invalid lookup: %s' % lookup_type)
|
|
return root_constraint
|
|
|
|
@property
|
|
def attnames(self):
|
|
return tuple([field.attname for field in self.local_related_fields])
|
|
|
|
def get_defaults(self):
|
|
return tuple([field.get_default() for field in self.local_related_fields])
|
|
|
|
def contribute_to_class(self, cls, name, virtual_only=False):
|
|
super(ForeignObject, self).contribute_to_class(cls, name, virtual_only=virtual_only)
|
|
setattr(cls, self.name, ReverseSingleRelatedObjectDescriptor(self))
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
# Internal FK's - i.e., those with a related name ending with '+' -
|
|
# and swapped models don't get a related descriptor.
|
|
if not self.rel.is_hidden() and not related.model._meta.swapped:
|
|
setattr(cls, related.get_accessor_name(), ForeignRelatedObjectsDescriptor(related))
|
|
if self.rel.limit_choices_to:
|
|
cls._meta.related_fkey_lookups.append(self.rel.limit_choices_to)
|
|
|
|
|
|
class ForeignKey(ForeignObject):
|
|
empty_strings_allowed = False
|
|
default_error_messages = {
|
|
'invalid': _('Model %(model)s with pk %(pk)r does not exist.')
|
|
}
|
|
description = _("Foreign Key (type determined by related field)")
|
|
|
|
def __init__(self, to, to_field=None, rel_class=ManyToOneRel,
|
|
db_constraint=True, **kwargs):
|
|
try:
|
|
to._meta.object_name.lower()
|
|
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
|
|
assert isinstance(to, six.string_types), "%s(%r) is invalid. First parameter to ForeignKey must be either a model, a model name, or the string %r" % (self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT)
|
|
else:
|
|
assert not to._meta.abstract, "%s cannot define a relation with abstract class %s" % (self.__class__.__name__, to._meta.object_name)
|
|
# For backwards compatibility purposes, we need to *try* and set
|
|
# the to_field during FK construction. It won't be guaranteed to
|
|
# be correct until contribute_to_class is called. Refs #12190.
|
|
to_field = to_field or (to._meta.pk and to._meta.pk.name)
|
|
|
|
if 'db_index' not in kwargs:
|
|
kwargs['db_index'] = True
|
|
|
|
self.db_constraint = db_constraint
|
|
|
|
kwargs['rel'] = rel_class(
|
|
self, to, to_field,
|
|
related_name=kwargs.pop('related_name', None),
|
|
related_query_name=kwargs.pop('related_query_name', None),
|
|
limit_choices_to=kwargs.pop('limit_choices_to', None),
|
|
parent_link=kwargs.pop('parent_link', False),
|
|
on_delete=kwargs.pop('on_delete', CASCADE),
|
|
)
|
|
super(ForeignKey, self).__init__(to, ['self'], [to_field], **kwargs)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super(ForeignKey, self).deconstruct()
|
|
# Handle the simpler arguments
|
|
if self.db_index:
|
|
del kwargs['db_index']
|
|
else:
|
|
kwargs['db_index'] = False
|
|
if self.db_constraint is not True:
|
|
kwargs['db_constraint'] = self.db_constraint
|
|
if self.rel.on_delete is not CASCADE:
|
|
kwargs['on_delete'] = self.rel.on_delete
|
|
# Rel needs more work.
|
|
if self.rel.field_name:
|
|
kwargs['to_field'] = self.rel.field_name
|
|
if isinstance(self.rel.to, six.string_types):
|
|
kwargs['to'] = self.rel.to
|
|
else:
|
|
kwargs['to'] = "%s.%s" % (self.rel.to._meta.app_label, self.rel.to._meta.object_name)
|
|
return name, path, args, kwargs
|
|
|
|
@property
|
|
def related_field(self):
|
|
return self.foreign_related_fields[0]
|
|
|
|
def get_reverse_path_info(self):
|
|
"""
|
|
Get path from the related model to this field's model.
|
|
"""
|
|
opts = self.model._meta
|
|
from_opts = self.rel.to._meta
|
|
pathinfos = [PathInfo(from_opts, opts, (opts.pk,), self.rel, not self.unique, False)]
|
|
return pathinfos
|
|
|
|
def validate(self, value, model_instance):
|
|
if self.rel.parent_link:
|
|
return
|
|
super(ForeignKey, self).validate(value, model_instance)
|
|
if value is None:
|
|
return
|
|
|
|
using = router.db_for_read(model_instance.__class__, instance=model_instance)
|
|
qs = self.rel.to._default_manager.using(using).filter(
|
|
**{self.rel.field_name: value}
|
|
)
|
|
qs = qs.complex_filter(self.rel.limit_choices_to)
|
|
if not qs.exists():
|
|
raise exceptions.ValidationError(
|
|
self.error_messages['invalid'],
|
|
code='invalid',
|
|
params={'model': self.rel.to._meta.verbose_name, 'pk': value},
|
|
)
|
|
|
|
def get_attname(self):
|
|
return '%s_id' % self.name
|
|
|
|
def get_attname_column(self):
|
|
attname = self.get_attname()
|
|
column = self.db_column or attname
|
|
return attname, column
|
|
|
|
def get_validator_unique_lookup_type(self):
|
|
return '%s__%s__exact' % (self.name, self.related_field.name)
|
|
|
|
def get_default(self):
|
|
"Here we check if the default value is an object and return the to_field if so."
|
|
field_default = super(ForeignKey, self).get_default()
|
|
if isinstance(field_default, self.rel.to):
|
|
return getattr(field_default, self.related_field.attname)
|
|
return field_default
|
|
|
|
def get_db_prep_save(self, value, connection):
|
|
if value == '' or value is None:
|
|
return None
|
|
else:
|
|
return self.related_field.get_db_prep_save(value,
|
|
connection=connection)
|
|
|
|
def value_to_string(self, obj):
|
|
if not obj:
|
|
# In required many-to-one fields with only one available choice,
|
|
# select that one available choice. Note: For SelectFields
|
|
# we have to check that the length of choices is *2*, not 1,
|
|
# because SelectFields always have an initial "blank" value.
|
|
if not self.blank and self.choices:
|
|
choice_list = self.get_choices_default()
|
|
if len(choice_list) == 2:
|
|
return smart_text(choice_list[1][0])
|
|
return super(ForeignKey, self).value_to_string(obj)
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
super(ForeignKey, self).contribute_to_related_class(cls, related)
|
|
if self.rel.field_name is None:
|
|
self.rel.field_name = cls._meta.pk.name
|
|
|
|
def formfield(self, **kwargs):
|
|
db = kwargs.pop('using', None)
|
|
if isinstance(self.rel.to, six.string_types):
|
|
raise ValueError("Cannot create form field for %r yet, because "
|
|
"its related model %r has not been loaded yet" %
|
|
(self.name, self.rel.to))
|
|
defaults = {
|
|
'form_class': forms.ModelChoiceField,
|
|
'queryset': self.rel.to._default_manager.using(db).complex_filter(self.rel.limit_choices_to),
|
|
'to_field_name': self.rel.field_name,
|
|
}
|
|
defaults.update(kwargs)
|
|
return super(ForeignKey, self).formfield(**defaults)
|
|
|
|
def db_type(self, connection):
|
|
# The database column type of a ForeignKey is the column type
|
|
# of the field to which it points. An exception is if the ForeignKey
|
|
# points to an AutoField/PositiveIntegerField/PositiveSmallIntegerField,
|
|
# in which case the column type is simply that of an IntegerField.
|
|
# If the database needs similar types for key fields however, the only
|
|
# thing we can do is making AutoField an IntegerField.
|
|
rel_field = self.related_field
|
|
if (isinstance(rel_field, AutoField) or
|
|
(not connection.features.related_fields_match_type and
|
|
isinstance(rel_field, (PositiveIntegerField,
|
|
PositiveSmallIntegerField)))):
|
|
return IntegerField().db_type(connection=connection)
|
|
return rel_field.db_type(connection=connection)
|
|
|
|
|
|
class OneToOneField(ForeignKey):
|
|
"""
|
|
A OneToOneField is essentially the same as a ForeignKey, with the exception
|
|
that always carries a "unique" constraint with it and the reverse relation
|
|
always returns the object pointed to (since there will only ever be one),
|
|
rather than returning a list.
|
|
"""
|
|
description = _("One-to-one relationship")
|
|
|
|
def __init__(self, to, to_field=None, **kwargs):
|
|
kwargs['unique'] = True
|
|
super(OneToOneField, self).__init__(to, to_field, OneToOneRel, **kwargs)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super(OneToOneField, self).deconstruct()
|
|
if "unique" in kwargs:
|
|
del kwargs['unique']
|
|
return name, path, args, kwargs
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
setattr(cls, related.get_accessor_name(),
|
|
SingleRelatedObjectDescriptor(related))
|
|
|
|
def formfield(self, **kwargs):
|
|
if self.rel.parent_link:
|
|
return None
|
|
return super(OneToOneField, self).formfield(**kwargs)
|
|
|
|
def save_form_data(self, instance, data):
|
|
if isinstance(data, self.rel.to):
|
|
setattr(instance, self.name, data)
|
|
else:
|
|
setattr(instance, self.attname, data)
|
|
|
|
|
|
def create_many_to_many_intermediary_model(field, klass):
|
|
from django.db import models
|
|
managed = True
|
|
if isinstance(field.rel.to, six.string_types) and field.rel.to != RECURSIVE_RELATIONSHIP_CONSTANT:
|
|
to_model = field.rel.to
|
|
to = to_model.split('.')[-1]
|
|
|
|
def set_managed(field, model, cls):
|
|
field.rel.through._meta.managed = model._meta.managed or cls._meta.managed
|
|
add_lazy_relation(klass, field, to_model, set_managed)
|
|
elif isinstance(field.rel.to, six.string_types):
|
|
to = klass._meta.object_name
|
|
to_model = klass
|
|
managed = klass._meta.managed
|
|
else:
|
|
to = field.rel.to._meta.object_name
|
|
to_model = field.rel.to
|
|
managed = klass._meta.managed or to_model._meta.managed
|
|
name = '%s_%s' % (klass._meta.object_name, field.name)
|
|
if field.rel.to == RECURSIVE_RELATIONSHIP_CONSTANT or to == klass._meta.object_name:
|
|
from_ = 'from_%s' % to.lower()
|
|
to = 'to_%s' % to.lower()
|
|
else:
|
|
from_ = klass._meta.model_name
|
|
to = to.lower()
|
|
meta = type('Meta', (object,), {
|
|
'db_table': field._get_m2m_db_table(klass._meta),
|
|
'managed': managed,
|
|
'auto_created': klass,
|
|
'app_label': klass._meta.app_label,
|
|
'db_tablespace': klass._meta.db_tablespace,
|
|
'unique_together': (from_, to),
|
|
'verbose_name': '%(from)s-%(to)s relationship' % {'from': from_, 'to': to},
|
|
'verbose_name_plural': '%(from)s-%(to)s relationships' % {'from': from_, 'to': to},
|
|
})
|
|
# Construct and return the new class.
|
|
return type(str(name), (models.Model,), {
|
|
'Meta': meta,
|
|
'__module__': klass.__module__,
|
|
from_: models.ForeignKey(klass, related_name='%s+' % name, db_tablespace=field.db_tablespace, db_constraint=field.rel.db_constraint),
|
|
to: models.ForeignKey(to_model, related_name='%s+' % name, db_tablespace=field.db_tablespace, db_constraint=field.rel.db_constraint)
|
|
})
|
|
|
|
|
|
class ManyToManyField(RelatedField):
|
|
description = _("Many-to-many relationship")
|
|
|
|
def __init__(self, to, db_constraint=True, **kwargs):
|
|
try:
|
|
assert not to._meta.abstract, "%s cannot define a relation with abstract class %s" % (self.__class__.__name__, to._meta.object_name)
|
|
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
|
|
assert isinstance(to, six.string_types), "%s(%r) is invalid. First parameter to ManyToManyField must be either a model, a model name, or the string %r" % (self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT)
|
|
# Class names must be ASCII in Python 2.x, so we forcibly coerce it here to break early if there's a problem.
|
|
to = str(to)
|
|
|
|
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
|
|
kwargs['rel'] = ManyToManyRel(to,
|
|
related_name=kwargs.pop('related_name', None),
|
|
related_query_name=kwargs.pop('related_query_name', None),
|
|
limit_choices_to=kwargs.pop('limit_choices_to', None),
|
|
symmetrical=kwargs.pop('symmetrical', to == RECURSIVE_RELATIONSHIP_CONSTANT),
|
|
through=kwargs.pop('through', None),
|
|
db_constraint=db_constraint,
|
|
)
|
|
|
|
self.db_table = kwargs.pop('db_table', None)
|
|
if kwargs['rel'].through is not None:
|
|
assert self.db_table is None, "Cannot specify a db_table if an intermediary model is used."
|
|
|
|
super(ManyToManyField, self).__init__(**kwargs)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super(ManyToManyField, self).deconstruct()
|
|
# Handle the simpler arguments
|
|
if self.rel.db_constraint is not True:
|
|
kwargs['db_constraint'] = self.db_constraint
|
|
if "help_text" in kwargs:
|
|
del kwargs['help_text']
|
|
# Rel needs more work.
|
|
if isinstance(self.rel.to, six.string_types):
|
|
kwargs['to'] = self.rel.to
|
|
else:
|
|
kwargs['to'] = "%s.%s" % (self.rel.to._meta.app_label, self.rel.to._meta.object_name)
|
|
return name, path, args, kwargs
|
|
|
|
def _get_path_info(self, direct=False):
|
|
"""
|
|
Called by both direct an indirect m2m traversal.
|
|
"""
|
|
pathinfos = []
|
|
int_model = self.rel.through
|
|
linkfield1 = int_model._meta.get_field_by_name(self.m2m_field_name())[0]
|
|
linkfield2 = int_model._meta.get_field_by_name(self.m2m_reverse_field_name())[0]
|
|
if direct:
|
|
join1infos = linkfield1.get_reverse_path_info()
|
|
join2infos = linkfield2.get_path_info()
|
|
else:
|
|
join1infos = linkfield2.get_reverse_path_info()
|
|
join2infos = linkfield1.get_path_info()
|
|
pathinfos.extend(join1infos)
|
|
pathinfos.extend(join2infos)
|
|
return pathinfos
|
|
|
|
def get_path_info(self):
|
|
return self._get_path_info(direct=True)
|
|
|
|
def get_reverse_path_info(self):
|
|
return self._get_path_info(direct=False)
|
|
|
|
def get_choices_default(self):
|
|
return Field.get_choices(self, include_blank=False)
|
|
|
|
def _get_m2m_db_table(self, opts):
|
|
"Function that can be curried to provide the m2m table name for this relation"
|
|
if self.rel.through is not None:
|
|
return self.rel.through._meta.db_table
|
|
elif self.db_table:
|
|
return self.db_table
|
|
else:
|
|
return util.truncate_name('%s_%s' % (opts.db_table, self.name),
|
|
connection.ops.max_name_length())
|
|
|
|
def _get_m2m_attr(self, related, attr):
|
|
"Function that can be curried to provide the source accessor or DB column name for the m2m table"
|
|
cache_attr = '_m2m_%s_cache' % attr
|
|
if hasattr(self, cache_attr):
|
|
return getattr(self, cache_attr)
|
|
for f in self.rel.through._meta.fields:
|
|
if hasattr(f, 'rel') and f.rel and f.rel.to == related.model:
|
|
setattr(self, cache_attr, getattr(f, attr))
|
|
return getattr(self, cache_attr)
|
|
|
|
def _get_m2m_reverse_attr(self, related, attr):
|
|
"Function that can be curried to provide the related accessor or DB column name for the m2m table"
|
|
cache_attr = '_m2m_reverse_%s_cache' % attr
|
|
if hasattr(self, cache_attr):
|
|
return getattr(self, cache_attr)
|
|
found = False
|
|
for f in self.rel.through._meta.fields:
|
|
if hasattr(f, 'rel') and f.rel and f.rel.to == related.parent_model:
|
|
if related.model == related.parent_model:
|
|
# If this is an m2m-intermediate to self,
|
|
# the first foreign key you find will be
|
|
# the source column. Keep searching for
|
|
# the second foreign key.
|
|
if found:
|
|
setattr(self, cache_attr, getattr(f, attr))
|
|
break
|
|
else:
|
|
found = True
|
|
else:
|
|
setattr(self, cache_attr, getattr(f, attr))
|
|
break
|
|
return getattr(self, cache_attr)
|
|
|
|
def value_to_string(self, obj):
|
|
data = ''
|
|
if obj:
|
|
qs = getattr(obj, self.name).all()
|
|
data = [instance._get_pk_val() for instance in qs]
|
|
else:
|
|
# In required many-to-many fields with only one available choice,
|
|
# select that one available choice.
|
|
if not self.blank:
|
|
choices_list = self.get_choices_default()
|
|
if len(choices_list) == 1:
|
|
data = [choices_list[0][0]]
|
|
return smart_text(data)
|
|
|
|
def contribute_to_class(self, cls, name):
|
|
# To support multiple relations to self, it's useful to have a non-None
|
|
# related name on symmetrical relations for internal reasons. The
|
|
# concept doesn't make a lot of sense externally ("you want me to
|
|
# specify *what* on my non-reversible relation?!"), so we set it up
|
|
# automatically. The funky name reduces the chance of an accidental
|
|
# clash.
|
|
if self.rel.symmetrical and (self.rel.to == "self" or self.rel.to == cls._meta.object_name):
|
|
self.rel.related_name = "%s_rel_+" % name
|
|
|
|
super(ManyToManyField, self).contribute_to_class(cls, name)
|
|
|
|
# The intermediate m2m model is not auto created if:
|
|
# 1) There is a manually specified intermediate, or
|
|
# 2) The class owning the m2m field is abstract.
|
|
# 3) The class owning the m2m field has been swapped out.
|
|
if not self.rel.through and not cls._meta.abstract and not cls._meta.swapped:
|
|
self.rel.through = create_many_to_many_intermediary_model(self, cls)
|
|
|
|
# Add the descriptor for the m2m relation
|
|
setattr(cls, self.name, ReverseManyRelatedObjectsDescriptor(self))
|
|
|
|
# Set up the accessor for the m2m table name for the relation
|
|
self.m2m_db_table = curry(self._get_m2m_db_table, cls._meta)
|
|
|
|
# Populate some necessary rel arguments so that cross-app relations
|
|
# work correctly.
|
|
if isinstance(self.rel.through, six.string_types):
|
|
def resolve_through_model(field, model, cls):
|
|
field.rel.through = model
|
|
add_lazy_relation(cls, self, self.rel.through, resolve_through_model)
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
# Internal M2Ms (i.e., those with a related name ending with '+')
|
|
# and swapped models don't get a related descriptor.
|
|
if not self.rel.is_hidden() and not related.model._meta.swapped:
|
|
setattr(cls, related.get_accessor_name(), ManyRelatedObjectsDescriptor(related))
|
|
|
|
# Set up the accessors for the column names on the m2m table
|
|
self.m2m_column_name = curry(self._get_m2m_attr, related, 'column')
|
|
self.m2m_reverse_name = curry(self._get_m2m_reverse_attr, related, 'column')
|
|
|
|
self.m2m_field_name = curry(self._get_m2m_attr, related, 'name')
|
|
self.m2m_reverse_field_name = curry(self._get_m2m_reverse_attr, related, 'name')
|
|
|
|
get_m2m_rel = curry(self._get_m2m_attr, related, 'rel')
|
|
self.m2m_target_field_name = lambda: get_m2m_rel().field_name
|
|
get_m2m_reverse_rel = curry(self._get_m2m_reverse_attr, related, 'rel')
|
|
self.m2m_reverse_target_field_name = lambda: get_m2m_reverse_rel().field_name
|
|
|
|
def set_attributes_from_rel(self):
|
|
pass
|
|
|
|
def value_from_object(self, obj):
|
|
"Returns the value of this field in the given model instance."
|
|
return getattr(obj, self.attname).all()
|
|
|
|
def save_form_data(self, instance, data):
|
|
setattr(instance, self.attname, data)
|
|
|
|
def formfield(self, **kwargs):
|
|
db = kwargs.pop('using', None)
|
|
defaults = {
|
|
'form_class': forms.ModelMultipleChoiceField,
|
|
'queryset': self.rel.to._default_manager.using(db).complex_filter(self.rel.limit_choices_to)
|
|
}
|
|
defaults.update(kwargs)
|
|
# If initial is passed in, it's a list of related objects, but the
|
|
# MultipleChoiceField takes a list of IDs.
|
|
if defaults.get('initial') is not None:
|
|
initial = defaults['initial']
|
|
if callable(initial):
|
|
initial = initial()
|
|
defaults['initial'] = [i._get_pk_val() for i in initial]
|
|
return super(ManyToManyField, self).formfield(**defaults)
|