929 lines
41 KiB
Python
929 lines
41 KiB
Python
from django.db import connection, transaction
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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, PositiveIntegerField, PositiveSmallIntegerField, FieldDoesNotExist
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from django.db.models.related import RelatedObject
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from django.db.models.query import QuerySet
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from django.db.models.query_utils import QueryWrapper
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from django.utils.encoding import smart_unicode
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from django.utils.translation import ugettext_lazy, string_concat, ungettext, ugettext as _
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from django.utils.functional import curry
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from django.core import exceptions
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from django import forms
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try:
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set
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except NameError:
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from sets import Set as set # Python 2.3 fallback
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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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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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# 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, 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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#HACK
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class RelatedField(object):
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def contribute_to_class(self, cls, name):
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sup = super(RelatedField, self)
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# Add an accessor to allow easy determination of the related query path for this field
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self.related_query_name = curry(self._get_related_query_name, cls._meta)
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if hasattr(sup, 'contribute_to_class'):
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sup.contribute_to_class(cls, name)
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if not cls._meta.abstract and self.rel.related_name:
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self.rel.related_name = self.rel.related_name % {'class': cls.__name__.lower()}
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other = self.rel.to
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if isinstance(other, basestring):
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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.object_name.lower() + '_' + 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.field_name = self.rel.field_name or self.rel.to._meta.pk.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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related = RelatedObject(other, cls, self)
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if not cls._meta.abstract:
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self.contribute_to_related_class(other, related)
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def get_db_prep_lookup(self, lookup_type, value):
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# If we are doing a lookup on a Related Field, we must be
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# comparing object instances. The value should be the PK of value,
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# not value itself.
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def pk_trace(value):
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# Value may be a primary key, or an object held in a relation.
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# If it is an object, then we need to get the primary key value for
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# that object. In certain conditions (especially one-to-one relations),
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# the primary key may itself be an object - so we need to keep drilling
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# down until we hit a value that can be used for a comparison.
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v, field = value, None
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try:
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while True:
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v, field = getattr(v, v._meta.pk.name), v._meta.pk
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except AttributeError:
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pass
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if field:
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if lookup_type in ('range', 'in'):
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v = [v]
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v = field.get_db_prep_lookup(lookup_type, v)
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if isinstance(v, list):
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v = v[0]
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return v
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if hasattr(value, 'as_sql'):
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sql, params = value.as_sql()
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return QueryWrapper(('(%s)' % sql), params)
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# FIXME: lt and gt are explicitally allowed to make
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# get_(next/prev)_by_date work; other lookups are not allowed since that
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# gets messy pretty quick. This is a good candidate for some refactoring
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# in the future.
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if lookup_type in ['exact', 'gt', 'lt']:
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return [pk_trace(value)]
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if lookup_type in ('range', 'in'):
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return [pk_trace(v) for v in value]
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elif lookup_type == 'isnull':
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return []
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raise TypeError, "Related Field has invalid lookup: %s" % lookup_type
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def _get_related_query_name(self, opts):
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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_name or opts.object_name.lower()
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class SingleRelatedObjectDescriptor(object):
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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 = '_%s_cache' % related.get_accessor_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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return getattr(instance, self.cache_name)
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except AttributeError:
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params = {'%s__pk' % self.related.field.name: instance._get_pk_val()}
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rel_obj = self.related.model._default_manager.get(**params)
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setattr(instance, self.cache_name, rel_obj)
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return rel_obj
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def __set__(self, instance, value):
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if instance is None:
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raise AttributeError, "%s must be accessed via instance" % self.related.opts.object_name
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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 == 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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# Set the value of the related field
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setattr(value, self.related.field.rel.get_related_field().attname, instance)
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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(object):
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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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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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cache_name = self.field.get_cache_name()
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try:
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return getattr(instance, cache_name)
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except AttributeError:
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val = getattr(instance, self.field.attname)
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if val is None:
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# If NULL is an allowed value, return it.
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if self.field.null:
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return None
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raise self.field.rel.to.DoesNotExist
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other_field = self.field.rel.get_related_field()
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if other_field.rel:
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params = {'%s__pk' % self.field.rel.field_name: val}
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else:
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params = {'%s__exact' % self.field.rel.field_name: val}
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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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rel_mgr = self.field.rel.to._default_manager
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if getattr(rel_mgr, 'use_for_related_fields', False):
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rel_obj = rel_mgr.get(**params)
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else:
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rel_obj = QuerySet(self.field.rel.to).get(**params)
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setattr(instance, cache_name, rel_obj)
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return rel_obj
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def __set__(self, instance, value):
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if instance is None:
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raise AttributeError, "%s must be accessed via instance" % self._field.name
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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 == 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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# Set the value of the related field
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try:
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val = getattr(value, self.field.rel.get_related_field().attname)
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except AttributeError:
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val = None
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setattr(instance, self.field.attname, val)
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# Since we already know what the related object is, seed the related
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# object cache 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.field.get_cache_name(), value)
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class ForeignRelatedObjectsDescriptor(object):
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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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# 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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rel_field = self.related.field
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rel_model = self.related.model
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# Dynamically create a class that subclasses the related
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# model's default manager.
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superclass = self.related.model._default_manager.__class__
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class RelatedManager(superclass):
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def get_query_set(self):
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return superclass.get_query_set(self).filter(**(self.core_filters))
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def add(self, *objs):
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for obj in objs:
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setattr(obj, rel_field.name, instance)
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obj.save()
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add.alters_data = True
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def create(self, **kwargs):
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kwargs.update({rel_field.name: instance})
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return super(RelatedManager, self).create(**kwargs)
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create.alters_data = True
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def get_or_create(self, **kwargs):
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# Update kwargs with the related object that this
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# ForeignRelatedObjectsDescriptor knows about.
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kwargs.update({rel_field.name: instance})
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return super(RelatedManager, self).get_or_create(**kwargs)
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get_or_create.alters_data = True
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# remove() and clear() are only provided if the ForeignKey can have a value of null.
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if rel_field.null:
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def remove(self, *objs):
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val = getattr(instance, rel_field.rel.get_related_field().attname)
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for obj in objs:
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# Is obj actually part of this descriptor set?
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if getattr(obj, rel_field.attname) == val:
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setattr(obj, rel_field.name, None)
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obj.save()
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else:
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raise rel_field.rel.to.DoesNotExist, "%r is not related to %r." % (obj, instance)
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remove.alters_data = True
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def clear(self):
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for obj in self.all():
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setattr(obj, rel_field.name, None)
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obj.save()
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clear.alters_data = True
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manager = RelatedManager()
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attname = rel_field.rel.get_related_field().name
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manager.core_filters = {'%s__%s' % (rel_field.name, attname):
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getattr(instance, attname)}
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manager.model = self.related.model
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return manager
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def __set__(self, instance, value):
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if instance is None:
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raise AttributeError, "Manager must be accessed via instance"
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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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def create_many_related_manager(superclass, through=False):
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"""Creates a manager that subclasses 'superclass' (which is a Manager)
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and adds behavior for many-to-many related objects."""
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class ManyRelatedManager(superclass):
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def __init__(self, model=None, core_filters=None, instance=None, symmetrical=None,
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join_table=None, source_col_name=None, target_col_name=None):
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super(ManyRelatedManager, self).__init__()
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self.core_filters = core_filters
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self.model = model
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self.symmetrical = symmetrical
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self.instance = instance
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self.join_table = join_table
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self.source_col_name = source_col_name
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self.target_col_name = target_col_name
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self.through = through
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self._pk_val = self.instance._get_pk_val()
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if self._pk_val is None:
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raise ValueError("%r instance needs to have a primary key value before a many-to-many relationship can be used." % instance.__class__.__name__)
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def get_query_set(self):
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return superclass.get_query_set(self)._next_is_sticky().filter(**(self.core_filters))
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# If the ManyToMany relation has an intermediary model,
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# the add and remove methods do not exist.
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if through is None:
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def add(self, *objs):
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self._add_items(self.source_col_name, self.target_col_name, *objs)
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# If this is a symmetrical m2m relation to self, add the mirror entry in the m2m table
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if self.symmetrical:
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self._add_items(self.target_col_name, self.source_col_name, *objs)
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add.alters_data = True
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def remove(self, *objs):
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self._remove_items(self.source_col_name, self.target_col_name, *objs)
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# If this is a symmetrical m2m relation to self, remove the mirror entry in the m2m table
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if self.symmetrical:
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self._remove_items(self.target_col_name, self.source_col_name, *objs)
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remove.alters_data = True
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def clear(self):
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self._clear_items(self.source_col_name)
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# If this is a symmetrical m2m relation to self, clear the mirror entry in the m2m table
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if self.symmetrical:
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self._clear_items(self.target_col_name)
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clear.alters_data = True
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def create(self, **kwargs):
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# This check needs to be done here, since we can't later remove this
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# from the method lookup table, as we do with add and remove.
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if through is not None:
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raise AttributeError, "Cannot use create() on a ManyToManyField which specifies an intermediary model. Use %s's Manager instead." % through
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new_obj = super(ManyRelatedManager, self).create(**kwargs)
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self.add(new_obj)
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return new_obj
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create.alters_data = True
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def get_or_create(self, **kwargs):
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obj, created = \
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super(ManyRelatedManager, self).get_or_create(**kwargs)
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# We only need to add() if created because if we got an object back
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# from get() then the relationship already exists.
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if created:
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self.add(obj)
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return obj, created
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get_or_create.alters_data = True
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def _add_items(self, source_col_name, target_col_name, *objs):
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# join_table: name of the m2m link table
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# source_col_name: the PK colname in join_table for the source object
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# target_col_name: the PK colname in join_table for the target object
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# *objs - objects to add. Either object instances, or primary keys of object instances.
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# If there aren't any objects, there is nothing to do.
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if objs:
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# Check that all the objects are of the right type
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new_ids = set()
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for obj in objs:
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if isinstance(obj, self.model):
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new_ids.add(obj._get_pk_val())
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else:
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new_ids.add(obj)
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# Add the newly created or already existing objects to the join table.
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# First find out which items are already added, to avoid adding them twice
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cursor = connection.cursor()
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cursor.execute("SELECT %s FROM %s WHERE %s = %%s AND %s IN (%s)" % \
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(target_col_name, self.join_table, source_col_name,
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target_col_name, ",".join(['%s'] * len(new_ids))),
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[self._pk_val] + list(new_ids))
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existing_ids = set([row[0] for row in cursor.fetchall()])
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# Add the ones that aren't there already
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for obj_id in (new_ids - existing_ids):
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cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
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(self.join_table, source_col_name, target_col_name),
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[self._pk_val, obj_id])
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transaction.commit_unless_managed()
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|
|
def _remove_items(self, source_col_name, target_col_name, *objs):
|
|
# source_col_name: the PK colname in join_table for the source object
|
|
# target_col_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(obj._get_pk_val())
|
|
else:
|
|
old_ids.add(obj)
|
|
# Remove the specified objects from the join table
|
|
cursor = connection.cursor()
|
|
cursor.execute("DELETE FROM %s WHERE %s = %%s AND %s IN (%s)" % \
|
|
(self.join_table, source_col_name,
|
|
target_col_name, ",".join(['%s'] * len(old_ids))),
|
|
[self._pk_val] + list(old_ids))
|
|
transaction.commit_unless_managed()
|
|
|
|
def _clear_items(self, source_col_name):
|
|
# source_col_name: the PK colname in join_table for the source object
|
|
cursor = connection.cursor()
|
|
cursor.execute("DELETE FROM %s WHERE %s = %%s" % \
|
|
(self.join_table, source_col_name),
|
|
[self._pk_val])
|
|
transaction.commit_unless_managed()
|
|
|
|
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
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
# Dynamically create a class that subclasses the related
|
|
# model's default manager.
|
|
rel_model = self.related.model
|
|
superclass = rel_model._default_manager.__class__
|
|
RelatedManager = create_many_related_manager(superclass, self.related.field.rel.through)
|
|
|
|
qn = connection.ops.quote_name
|
|
manager = RelatedManager(
|
|
model=rel_model,
|
|
core_filters={'%s__pk' % self.related.field.name: instance._get_pk_val()},
|
|
instance=instance,
|
|
symmetrical=False,
|
|
join_table=qn(self.related.field.m2m_db_table()),
|
|
source_col_name=qn(self.related.field.m2m_reverse_name()),
|
|
target_col_name=qn(self.related.field.m2m_column_name())
|
|
)
|
|
|
|
return manager
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "Manager must be accessed via instance"
|
|
|
|
through = getattr(self.related.field.rel, 'through', None)
|
|
if through is not None:
|
|
raise AttributeError, "Cannot set values on a ManyToManyField which specifies an intermediary model. Use %s's Manager instead." % through
|
|
|
|
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
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
# Dynamically create a class that subclasses the related
|
|
# model's default manager.
|
|
rel_model=self.field.rel.to
|
|
superclass = rel_model._default_manager.__class__
|
|
RelatedManager = create_many_related_manager(superclass, self.field.rel.through)
|
|
|
|
qn = connection.ops.quote_name
|
|
manager = RelatedManager(
|
|
model=rel_model,
|
|
core_filters={'%s__pk' % self.field.related_query_name(): instance._get_pk_val()},
|
|
instance=instance,
|
|
symmetrical=(self.field.rel.symmetrical and instance.__class__ == rel_model),
|
|
join_table=qn(self.field.m2m_db_table()),
|
|
source_col_name=qn(self.field.m2m_column_name()),
|
|
target_col_name=qn(self.field.m2m_reverse_name())
|
|
)
|
|
|
|
return manager
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "Manager must be accessed via instance"
|
|
|
|
through = getattr(self.field.rel, 'through', None)
|
|
if through is not None:
|
|
raise AttributeError, "Cannot set values on a ManyToManyField which specifies an intermediary model. Use %s's Manager instead." % through
|
|
|
|
manager = self.__get__(instance)
|
|
manager.clear()
|
|
manager.add(*value)
|
|
|
|
class ManyToOneRel(object):
|
|
def __init__(self, to, field_name, related_name=None,
|
|
limit_choices_to=None, lookup_overrides=None, parent_link=False):
|
|
try:
|
|
to._meta
|
|
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
|
|
assert isinstance(to, basestring), "'to' must be either a model, a model name or the string %r" % RECURSIVE_RELATIONSHIP_CONSTANT
|
|
self.to, self.field_name = to, field_name
|
|
self.related_name = related_name
|
|
if limit_choices_to is None:
|
|
limit_choices_to = {}
|
|
self.limit_choices_to = limit_choices_to
|
|
self.lookup_overrides = lookup_overrides or {}
|
|
self.multiple = True
|
|
self.parent_link = parent_link
|
|
|
|
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]
|
|
|
|
class OneToOneRel(ManyToOneRel):
|
|
def __init__(self, to, field_name, related_name=None,
|
|
limit_choices_to=None, lookup_overrides=None, parent_link=False):
|
|
super(OneToOneRel, self).__init__(to, field_name,
|
|
related_name=related_name, limit_choices_to=limit_choices_to,
|
|
lookup_overrides=lookup_overrides, parent_link=parent_link)
|
|
self.multiple = False
|
|
|
|
class ManyToManyRel(object):
|
|
def __init__(self, to, related_name=None, limit_choices_to=None,
|
|
symmetrical=True, through=None):
|
|
self.to = to
|
|
self.related_name = related_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
|
|
|
|
class ForeignKey(RelatedField, Field):
|
|
empty_strings_allowed = False
|
|
def __init__(self, to, to_field=None, rel_class=ManyToOneRel, **kwargs):
|
|
try:
|
|
to_name = to._meta.object_name.lower()
|
|
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
|
|
assert isinstance(to, basestring), "%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)
|
|
to_field = to_field or to._meta.pk.name
|
|
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
|
|
|
|
kwargs['rel'] = rel_class(to, to_field,
|
|
related_name=kwargs.pop('related_name', None),
|
|
limit_choices_to=kwargs.pop('limit_choices_to', None),
|
|
lookup_overrides=kwargs.pop('lookup_overrides', None),
|
|
parent_link=kwargs.pop('parent_link', False))
|
|
Field.__init__(self, **kwargs)
|
|
|
|
self.db_index = True
|
|
|
|
def get_attname(self):
|
|
return '%s_id' % self.name
|
|
|
|
def get_validator_unique_lookup_type(self):
|
|
return '%s__%s__exact' % (self.name, self.rel.get_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.rel.get_related_field().attname)
|
|
return field_default
|
|
|
|
def get_db_prep_save(self, value):
|
|
if value == '' or value == None:
|
|
return None
|
|
else:
|
|
return self.rel.get_related_field().get_db_prep_save(value)
|
|
|
|
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_unicode(choice_list[1][0])
|
|
return Field.value_to_string(self, obj)
|
|
|
|
def contribute_to_class(self, cls, name):
|
|
super(ForeignKey, self).contribute_to_class(cls, name)
|
|
setattr(cls, self.name, ReverseSingleRelatedObjectDescriptor(self))
|
|
if isinstance(self.rel.to, basestring):
|
|
target = self.rel.to
|
|
else:
|
|
target = self.rel.to._meta.db_table
|
|
cls._meta.duplicate_targets[self.column] = (target, "o2m")
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
setattr(cls, related.get_accessor_name(), ForeignRelatedObjectsDescriptor(related))
|
|
|
|
def formfield(self, **kwargs):
|
|
defaults = {
|
|
'form_class': forms.ModelChoiceField,
|
|
'queryset': self.rel.to._default_manager.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):
|
|
# 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.rel.get_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()
|
|
return rel_field.db_type()
|
|
|
|
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.
|
|
"""
|
|
def __init__(self, to, to_field=None, **kwargs):
|
|
kwargs['unique'] = True
|
|
super(OneToOneField, self).__init__(to, to_field, OneToOneRel, **kwargs)
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
setattr(cls, related.get_accessor_name(),
|
|
SingleRelatedObjectDescriptor(related))
|
|
if not cls._meta.one_to_one_field:
|
|
cls._meta.one_to_one_field = self
|
|
|
|
def formfield(self, **kwargs):
|
|
if self.rel.parent_link:
|
|
return None
|
|
return super(OneToOneField, self).formfield(**kwargs)
|
|
|
|
class ManyToManyField(RelatedField, Field):
|
|
def __init__(self, to, **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, basestring), "%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)
|
|
|
|
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
|
|
kwargs['rel'] = ManyToManyRel(to,
|
|
related_name=kwargs.pop('related_name', None),
|
|
limit_choices_to=kwargs.pop('limit_choices_to', None),
|
|
symmetrical=kwargs.pop('symmetrical', True),
|
|
through=kwargs.pop('through', None))
|
|
|
|
self.db_table = kwargs.pop('db_table', None)
|
|
if kwargs['rel'].through is not None:
|
|
self.creates_table = False
|
|
assert self.db_table is None, "Cannot specify a db_table if an intermediary model is used."
|
|
else:
|
|
self.creates_table = True
|
|
|
|
Field.__init__(self, **kwargs)
|
|
|
|
msg = ugettext_lazy('Hold down "Control", or "Command" on a Mac, to select more than one.')
|
|
self.help_text = string_concat(self.help_text, ' ', msg)
|
|
|
|
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_model._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_column_name(self, related):
|
|
"Function that can be curried to provide the source column name for the m2m table"
|
|
try:
|
|
return self._m2m_column_name_cache
|
|
except:
|
|
if self.rel.through is not None:
|
|
for f in self.rel.through_model._meta.fields:
|
|
if hasattr(f,'rel') and f.rel and f.rel.to == related.model:
|
|
self._m2m_column_name_cache = f.column
|
|
break
|
|
# If this is an m2m relation to self, avoid the inevitable name clash
|
|
elif related.model == related.parent_model:
|
|
self._m2m_column_name_cache = 'from_' + related.model._meta.object_name.lower() + '_id'
|
|
else:
|
|
self._m2m_column_name_cache = related.model._meta.object_name.lower() + '_id'
|
|
|
|
# Return the newly cached value
|
|
return self._m2m_column_name_cache
|
|
|
|
def _get_m2m_reverse_name(self, related):
|
|
"Function that can be curried to provide the related column name for the m2m table"
|
|
try:
|
|
return self._m2m_reverse_name_cache
|
|
except:
|
|
if self.rel.through is not None:
|
|
found = False
|
|
for f in self.rel.through_model._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:
|
|
self._m2m_reverse_name_cache = f.column
|
|
break
|
|
else:
|
|
found = True
|
|
else:
|
|
self._m2m_reverse_name_cache = f.column
|
|
break
|
|
# If this is an m2m relation to self, avoid the inevitable name clash
|
|
elif related.model == related.parent_model:
|
|
self._m2m_reverse_name_cache = 'to_' + related.parent_model._meta.object_name.lower() + '_id'
|
|
else:
|
|
self._m2m_reverse_name_cache = related.parent_model._meta.object_name.lower() + '_id'
|
|
|
|
# Return the newly cached value
|
|
return self._m2m_reverse_name_cache
|
|
|
|
def isValidIDList(self, field_data, all_data):
|
|
"Validates that the value is a valid list of foreign keys"
|
|
mod = self.rel.to
|
|
try:
|
|
pks = map(int, field_data.split(','))
|
|
except ValueError:
|
|
# the CommaSeparatedIntegerField validator will catch this error
|
|
return
|
|
objects = mod._default_manager.in_bulk(pks)
|
|
if len(objects) != len(pks):
|
|
badkeys = [k for k in pks if k not in objects]
|
|
raise exceptions.ValidationError(
|
|
ungettext("Please enter valid %(self)s IDs. The value %(value)r is invalid.",
|
|
"Please enter valid %(self)s IDs. The values %(value)r are invalid.",
|
|
len(badkeys)) % {
|
|
'self': self.verbose_name,
|
|
'value': len(badkeys) == 1 and badkeys[0] or tuple(badkeys),
|
|
})
|
|
|
|
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_unicode(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" and self.rel.related_name is None:
|
|
self.rel.related_name = "%s_rel_+" % name
|
|
|
|
super(ManyToManyField, self).contribute_to_class(cls, name)
|
|
# 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, basestring):
|
|
def resolve_through_model(field, model, cls):
|
|
field.rel.through_model = model
|
|
add_lazy_relation(cls, self, self.rel.through, resolve_through_model)
|
|
elif self.rel.through:
|
|
self.rel.through_model = self.rel.through
|
|
self.rel.through = self.rel.through._meta.object_name
|
|
|
|
if isinstance(self.rel.to, basestring):
|
|
target = self.rel.to
|
|
else:
|
|
target = self.rel.to._meta.db_table
|
|
cls._meta.duplicate_targets[self.column] = (target, "m2m")
|
|
|
|
def contribute_to_related_class(self, cls, related):
|
|
# m2m relations to self do not have a ManyRelatedObjectsDescriptor,
|
|
# as it would be redundant - unless the field is non-symmetrical.
|
|
if related.model != related.parent_model or not self.rel.symmetrical:
|
|
# Add the descriptor for the m2m relation
|
|
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_column_name, related)
|
|
self.m2m_reverse_name = curry(self._get_m2m_reverse_name, related)
|
|
|
|
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):
|
|
defaults = {'form_class': forms.ModelMultipleChoiceField, 'queryset': self.rel.to._default_manager.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:
|
|
defaults['initial'] = [i._get_pk_val() for i in defaults['initial']]
|
|
return super(ManyToManyField, self).formfield(**defaults)
|
|
|
|
def db_type(self):
|
|
# A ManyToManyField is not represented by a single column,
|
|
# so return None.
|
|
return None
|
|
|