1026 lines
45 KiB
Python
1026 lines
45 KiB
Python
from django.db import connection, transaction
|
|
from django.db.backends import util
|
|
from django.db.models import signals, get_model
|
|
from django.db.models.fields import AutoField, Field, IntegerField, PositiveIntegerField, PositiveSmallIntegerField, FieldDoesNotExist
|
|
from django.db.models.related import RelatedObject
|
|
from django.db.models.query import QuerySet
|
|
from django.db.models.query_utils import QueryWrapper
|
|
from django.utils.encoding import smart_unicode
|
|
from django.utils.translation import ugettext_lazy, string_concat, ungettext, ugettext as _
|
|
from django.utils.functional import curry
|
|
from django.core import exceptions
|
|
from django import forms
|
|
|
|
try:
|
|
set
|
|
except NameError:
|
|
from sets import Set as set # Python 2.3 fallback
|
|
|
|
RECURSIVE_RELATIONSHIP_CONSTANT = 'self'
|
|
|
|
pending_lookups = {}
|
|
|
|
def add_lazy_relation(cls, field, relation, operation):
|
|
"""
|
|
Adds a lookup on ``cls`` when a related field is defined using a string,
|
|
i.e.::
|
|
|
|
class MyModel(Model):
|
|
fk = ForeignKey("AnotherModel")
|
|
|
|
This string can be:
|
|
|
|
* RECURSIVE_RELATIONSHIP_CONSTANT (i.e. "self") to indicate a recursive
|
|
relation.
|
|
|
|
* The name of a model (i.e "AnotherModel") to indicate another model in
|
|
the same app.
|
|
|
|
* An app-label and model name (i.e. "someapp.AnotherModel") to indicate
|
|
another model in a different app.
|
|
|
|
If the other model hasn't yet been loaded -- almost a given if you're using
|
|
lazy relationships -- then the relation won't be set up until the
|
|
class_prepared signal fires at the end of model initialization.
|
|
|
|
operation is the work that must be performed once the relation can be resolved.
|
|
"""
|
|
# Check for recursive relations
|
|
if relation == RECURSIVE_RELATIONSHIP_CONSTANT:
|
|
app_label = cls._meta.app_label
|
|
model_name = cls.__name__
|
|
|
|
else:
|
|
# Look for an "app.Model" relation
|
|
try:
|
|
app_label, model_name = relation.split(".")
|
|
except ValueError:
|
|
# If we can't split, assume a model in current app
|
|
app_label = cls._meta.app_label
|
|
model_name = relation
|
|
except AttributeError:
|
|
# If it doesn't have a split it's actually a model class
|
|
app_label = relation._meta.app_label
|
|
model_name = relation._meta.object_name
|
|
|
|
# Try to look up the related model, and if it's already loaded resolve the
|
|
# string right away. If get_model returns None, it means that the related
|
|
# model isn't loaded yet, so we need to pend the relation until the class
|
|
# is prepared.
|
|
model = get_model(app_label, model_name, False)
|
|
if model:
|
|
operation(field, model, cls)
|
|
else:
|
|
key = (app_label, model_name)
|
|
value = (cls, field, operation)
|
|
pending_lookups.setdefault(key, []).append(value)
|
|
|
|
def do_pending_lookups(sender, **kwargs):
|
|
"""
|
|
Handle any pending relations to the sending model. Sent from class_prepared.
|
|
"""
|
|
key = (sender._meta.app_label, sender.__name__)
|
|
for cls, field, operation in pending_lookups.pop(key, []):
|
|
operation(field, sender, cls)
|
|
|
|
signals.class_prepared.connect(do_pending_lookups)
|
|
|
|
#HACK
|
|
class RelatedField(object):
|
|
def contribute_to_class(self, cls, name):
|
|
sup = super(RelatedField, self)
|
|
|
|
# Add an accessor to allow easy determination of the related query path for this field
|
|
self.related_query_name = curry(self._get_related_query_name, cls._meta)
|
|
|
|
if hasattr(sup, 'contribute_to_class'):
|
|
sup.contribute_to_class(cls, name)
|
|
|
|
if not cls._meta.abstract and self.rel.related_name:
|
|
self.rel.related_name = self.rel.related_name % {'class': cls.__name__.lower()}
|
|
|
|
other = self.rel.to
|
|
if isinstance(other, basestring) or other._meta.pk is None:
|
|
def resolve_related_class(field, model, cls):
|
|
field.rel.to = model
|
|
field.do_related_class(model, cls)
|
|
add_lazy_relation(cls, self, other, resolve_related_class)
|
|
else:
|
|
self.do_related_class(other, cls)
|
|
|
|
def set_attributes_from_rel(self):
|
|
self.name = self.name or (self.rel.to._meta.object_name.lower() + '_' + self.rel.to._meta.pk.name)
|
|
if self.verbose_name is None:
|
|
self.verbose_name = self.rel.to._meta.verbose_name
|
|
self.rel.field_name = self.rel.field_name or self.rel.to._meta.pk.name
|
|
|
|
def do_related_class(self, other, cls):
|
|
self.set_attributes_from_rel()
|
|
self.related = RelatedObject(other, cls, self)
|
|
if not cls._meta.abstract:
|
|
self.contribute_to_related_class(other, self.related)
|
|
|
|
def get_db_prep_lookup(self, lookup_type, value):
|
|
# If we are doing a lookup on a Related Field, we must be
|
|
# comparing object instances. The value should be the PK of value,
|
|
# not value itself.
|
|
def pk_trace(value):
|
|
# Value may be a primary key, or an object held in a relation.
|
|
# If it is an object, then we need to get the primary key value for
|
|
# that object. In certain conditions (especially one-to-one relations),
|
|
# the primary key may itself be an object - so we need to keep drilling
|
|
# down until we hit a value that can be used for a comparison.
|
|
v, field = value, None
|
|
try:
|
|
while True:
|
|
v, field = getattr(v, v._meta.pk.name), v._meta.pk
|
|
except AttributeError:
|
|
pass
|
|
|
|
if field:
|
|
if lookup_type in ('range', 'in'):
|
|
v = [v]
|
|
v = field.get_db_prep_lookup(lookup_type, v)
|
|
if isinstance(v, list):
|
|
v = v[0]
|
|
return v
|
|
|
|
if hasattr(value, 'as_sql') or hasattr(value, '_as_sql'):
|
|
# If the value has a relabel_aliases method, it will need to
|
|
# be invoked before the final SQL is evaluated
|
|
if hasattr(value, 'relabel_aliases'):
|
|
return value
|
|
if hasattr(value, 'as_sql'):
|
|
sql, params = value.as_sql()
|
|
else:
|
|
sql, params = value._as_sql()
|
|
return QueryWrapper(('(%s)' % sql), params)
|
|
|
|
# FIXME: lt and gt are explicitally allowed to make
|
|
# get_(next/prev)_by_date work; other lookups are not allowed since that
|
|
# gets messy pretty quick. This is a good candidate for some refactoring
|
|
# in the future.
|
|
if lookup_type in ['exact', 'gt', 'lt', 'gte', 'lte']:
|
|
return [pk_trace(value)]
|
|
if lookup_type in ('range', 'in'):
|
|
return [pk_trace(v) for v in value]
|
|
elif lookup_type == 'isnull':
|
|
return []
|
|
raise TypeError, "Related Field has invalid lookup: %s" % lookup_type
|
|
|
|
def _get_related_query_name(self, opts):
|
|
# This method defines the name that can be used to identify this
|
|
# related object in a table-spanning query. It uses the lower-cased
|
|
# object_name by default, but this can be overridden with the
|
|
# "related_name" option.
|
|
return self.rel.related_name or opts.object_name.lower()
|
|
|
|
class SingleRelatedObjectDescriptor(object):
|
|
# This class provides the functionality that makes the related-object
|
|
# managers available as attributes on a model class, for fields that have
|
|
# a single "remote" value, on the class pointed to by a related field.
|
|
# In the example "place.restaurant", the restaurant attribute is a
|
|
# SingleRelatedObjectDescriptor instance.
|
|
def __init__(self, related):
|
|
self.related = related
|
|
self.cache_name = '_%s_cache' % related.get_accessor_name()
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
try:
|
|
return getattr(instance, self.cache_name)
|
|
except AttributeError:
|
|
params = {'%s__pk' % self.related.field.name: instance._get_pk_val()}
|
|
rel_obj = self.related.model._base_manager.get(**params)
|
|
setattr(instance, self.cache_name, rel_obj)
|
|
return rel_obj
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "%s must be accessed via instance" % self.related.opts.object_name
|
|
|
|
# The similarity of the code below to the code in
|
|
# ReverseSingleRelatedObjectDescriptor is annoying, but there's a bunch
|
|
# of small differences that would make a common base class convoluted.
|
|
|
|
# If null=True, we can assign null here, but otherwise the value needs
|
|
# to be an instance of the related class.
|
|
if value is None and self.related.field.null == False:
|
|
raise ValueError('Cannot assign None: "%s.%s" does not allow null values.' %
|
|
(instance._meta.object_name, self.related.get_accessor_name()))
|
|
elif value is not None and not isinstance(value, self.related.model):
|
|
raise ValueError('Cannot assign "%r": "%s.%s" must be a "%s" instance.' %
|
|
(value, instance._meta.object_name,
|
|
self.related.get_accessor_name(), self.related.opts.object_name))
|
|
|
|
# Set the value of the related field to the value of the related object's related field
|
|
setattr(value, self.related.field.attname, getattr(instance, self.related.field.rel.get_related_field().attname))
|
|
|
|
# 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
|
|
# object you just set.
|
|
setattr(instance, self.cache_name, value)
|
|
setattr(value, self.related.field.get_cache_name(), instance)
|
|
|
|
class ReverseSingleRelatedObjectDescriptor(object):
|
|
# This class provides the functionality that makes the related-object
|
|
# managers available as attributes on a model class, for fields that have
|
|
# a single "remote" value, on the class that defines the related field.
|
|
# In the example "choice.poll", the poll attribute is a
|
|
# ReverseSingleRelatedObjectDescriptor instance.
|
|
def __init__(self, field_with_rel):
|
|
self.field = field_with_rel
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
cache_name = self.field.get_cache_name()
|
|
try:
|
|
return getattr(instance, cache_name)
|
|
except AttributeError:
|
|
val = getattr(instance, self.field.attname)
|
|
if val is None:
|
|
# If NULL is an allowed value, return it.
|
|
if self.field.null:
|
|
return None
|
|
raise self.field.rel.to.DoesNotExist
|
|
other_field = self.field.rel.get_related_field()
|
|
if other_field.rel:
|
|
params = {'%s__pk' % self.field.rel.field_name: val}
|
|
else:
|
|
params = {'%s__exact' % self.field.rel.field_name: val}
|
|
|
|
# If the related manager indicates that it should be used for
|
|
# related fields, respect that.
|
|
rel_mgr = self.field.rel.to._default_manager
|
|
if getattr(rel_mgr, 'use_for_related_fields', False):
|
|
rel_obj = rel_mgr.get(**params)
|
|
else:
|
|
rel_obj = QuerySet(self.field.rel.to).get(**params)
|
|
setattr(instance, cache_name, rel_obj)
|
|
return rel_obj
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "%s must be accessed via instance" % self._field.name
|
|
|
|
# If null=True, we can assign null here, but otherwise the value needs
|
|
# to be an instance of the related class.
|
|
if value is None and self.field.null == False:
|
|
raise ValueError('Cannot assign None: "%s.%s" does not allow null values.' %
|
|
(instance._meta.object_name, self.field.name))
|
|
elif value is not None and not isinstance(value, self.field.rel.to):
|
|
raise ValueError('Cannot assign "%r": "%s.%s" must be a "%s" instance.' %
|
|
(value, instance._meta.object_name,
|
|
self.field.name, self.field.rel.to._meta.object_name))
|
|
|
|
# If we're setting the value of a OneToOneField to None, we need to clear
|
|
# out the cache on any old related object. Otherwise, deleting the
|
|
# previously-related object will also cause this object to be deleted,
|
|
# which is wrong.
|
|
if value is None:
|
|
# Look up the previously-related object, which may still be available
|
|
# since we've not yet cleared out the related field.
|
|
# Use the cache directly, instead of the accessor; if we haven't
|
|
# populated the cache, then we don't care - we're only accessing
|
|
# the object to invalidate the accessor cache, so there's no
|
|
# need to populate the cache just to expire it again.
|
|
related = getattr(instance, self.field.get_cache_name(), None)
|
|
|
|
# If we've got an old related object, we need to clear out its
|
|
# cache. This cache also might not exist if the related object
|
|
# hasn't been accessed yet.
|
|
if related:
|
|
cache_name = '_%s_cache' % self.field.related.get_accessor_name()
|
|
try:
|
|
delattr(related, cache_name)
|
|
except AttributeError:
|
|
pass
|
|
|
|
# Set the value of the related field
|
|
try:
|
|
val = getattr(value, self.field.rel.get_related_field().attname)
|
|
except AttributeError:
|
|
val = None
|
|
setattr(instance, self.field.attname, val)
|
|
|
|
# Since we already know what the related object is, seed the related
|
|
# object cache now, too. This avoids another db hit if you get the
|
|
# object you just set.
|
|
setattr(instance, self.field.get_cache_name(), value)
|
|
|
|
class ForeignRelatedObjectsDescriptor(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 ForeignKey pointed at them by
|
|
# some other model. In the example "poll.choice_set", the choice_set
|
|
# attribute is a ForeignRelatedObjectsDescriptor instance.
|
|
def __init__(self, related):
|
|
self.related = related # RelatedObject instance
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
return self.create_manager(instance,
|
|
self.related.model._default_manager.__class__)
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "Manager must be accessed via instance"
|
|
|
|
manager = self.__get__(instance)
|
|
# If the foreign key can support nulls, then completely clear the related set.
|
|
# Otherwise, just move the named objects into the set.
|
|
if self.related.field.null:
|
|
manager.clear()
|
|
manager.add(*value)
|
|
|
|
def delete_manager(self, instance):
|
|
"""
|
|
Returns a queryset based on the related model's base manager (rather
|
|
than the default manager, as returned by __get__). Used by
|
|
Model.delete().
|
|
"""
|
|
return self.create_manager(instance,
|
|
self.related.model._base_manager.__class__)
|
|
|
|
def create_manager(self, instance, superclass):
|
|
"""
|
|
Creates the managers used by other methods (__get__() and delete()).
|
|
"""
|
|
rel_field = self.related.field
|
|
rel_model = self.related.model
|
|
|
|
class RelatedManager(superclass):
|
|
def get_query_set(self):
|
|
return superclass.get_query_set(self).filter(**(self.core_filters))
|
|
|
|
def add(self, *objs):
|
|
for obj in objs:
|
|
if not isinstance(obj, self.model):
|
|
raise TypeError, "'%s' instance expected" % self.model._meta.object_name
|
|
setattr(obj, rel_field.name, instance)
|
|
obj.save()
|
|
add.alters_data = True
|
|
|
|
def create(self, **kwargs):
|
|
kwargs.update({rel_field.name: instance})
|
|
return super(RelatedManager, self).create(**kwargs)
|
|
create.alters_data = True
|
|
|
|
def get_or_create(self, **kwargs):
|
|
# Update kwargs with the related object that this
|
|
# ForeignRelatedObjectsDescriptor knows about.
|
|
kwargs.update({rel_field.name: instance})
|
|
return super(RelatedManager, self).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 = getattr(instance, rel_field.rel.get_related_field().attname)
|
|
for obj in objs:
|
|
# Is obj actually part of this descriptor set?
|
|
if getattr(obj, rel_field.attname) == val:
|
|
setattr(obj, rel_field.name, None)
|
|
obj.save()
|
|
else:
|
|
raise rel_field.rel.to.DoesNotExist, "%r is not related to %r." % (obj, instance)
|
|
remove.alters_data = True
|
|
|
|
def clear(self):
|
|
for obj in self.all():
|
|
setattr(obj, rel_field.name, None)
|
|
obj.save()
|
|
clear.alters_data = True
|
|
|
|
manager = RelatedManager()
|
|
attname = rel_field.rel.get_related_field().name
|
|
manager.core_filters = {'%s__%s' % (rel_field.name, attname):
|
|
getattr(instance, attname)}
|
|
manager.model = self.related.model
|
|
|
|
return manager
|
|
|
|
def create_many_related_manager(superclass, rel=False):
|
|
"""Creates a manager that subclasses 'superclass' (which is a Manager)
|
|
and adds behavior for many-to-many related objects."""
|
|
through = rel.through
|
|
class ManyRelatedManager(superclass):
|
|
def __init__(self, model=None, core_filters=None, instance=None, symmetrical=None,
|
|
join_table=None, source_field_name=None, target_field_name=None):
|
|
super(ManyRelatedManager, self).__init__()
|
|
self.core_filters = core_filters
|
|
self.model = model
|
|
self.symmetrical = symmetrical
|
|
self.instance = instance
|
|
self.source_field_name = source_field_name
|
|
self.target_field_name = target_field_name
|
|
self.through = through
|
|
self._pk_val = self.instance.pk
|
|
if self._pk_val 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_query_set(self):
|
|
return superclass.get_query_set(self)._next_is_sticky().filter(**(self.core_filters))
|
|
|
|
# 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 rel.through._meta.auto_created:
|
|
opts = 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)
|
|
new_obj = super(ManyRelatedManager, self).create(**kwargs)
|
|
self.add(new_obj)
|
|
return new_obj
|
|
create.alters_data = True
|
|
|
|
def get_or_create(self, **kwargs):
|
|
obj, created = \
|
|
super(ManyRelatedManager, self).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):
|
|
# join_table: name of the m2m link table
|
|
# source_field_name: the PK fieldname in join_table for the source object
|
|
# target_col_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):
|
|
new_ids.add(obj.pk)
|
|
elif isinstance(obj, Model):
|
|
raise TypeError, "'%s' instance expected" % self.model._meta.object_name
|
|
else:
|
|
new_ids.add(obj)
|
|
vals = self.through._default_manager.values_list(target_field_name, flat=True)
|
|
vals = vals.filter(**{
|
|
source_field_name: self._pk_val,
|
|
'%s__in' % target_field_name: new_ids,
|
|
})
|
|
vals = set(vals)
|
|
|
|
# Add the ones that aren't there already
|
|
for obj_id in (new_ids - vals):
|
|
self.through._default_manager.create(**{
|
|
'%s_id' % source_field_name: self._pk_val,
|
|
'%s_id' % target_field_name: obj_id,
|
|
})
|
|
|
|
def _remove_items(self, source_field_name, target_field_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.pk)
|
|
else:
|
|
old_ids.add(obj)
|
|
# Remove the specified objects from the join table
|
|
self.through._default_manager.filter(**{
|
|
source_field_name: self._pk_val,
|
|
'%s__in' % target_field_name: old_ids
|
|
}).delete()
|
|
|
|
def _clear_items(self, source_field_name):
|
|
# source_col_name: the PK colname in join_table for the source object
|
|
self.through._default_manager.filter(**{
|
|
source_field_name: self._pk_val
|
|
}).delete()
|
|
|
|
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)
|
|
|
|
manager = RelatedManager(
|
|
model=rel_model,
|
|
core_filters={'%s__pk' % self.related.field.name: instance._get_pk_val()},
|
|
instance=instance,
|
|
symmetrical=False,
|
|
source_field_name=self.related.field.m2m_reverse_field_name(),
|
|
target_field_name=self.related.field.m2m_field_name()
|
|
)
|
|
|
|
return manager
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "Manager must be accessed via instance"
|
|
|
|
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
|
|
# through is provided so that you have easy access to the through
|
|
# model (Book.authors.through) for inlines, etc.
|
|
self.through = m2m_field.rel.through
|
|
|
|
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)
|
|
|
|
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 isinstance(instance, rel_model)),
|
|
source_field_name=self.field.m2m_field_name(),
|
|
target_field_name=self.field.m2m_reverse_field_name()
|
|
)
|
|
|
|
return manager
|
|
|
|
def __set__(self, instance, value):
|
|
if instance is None:
|
|
raise AttributeError, "Manager must be accessed via instance"
|
|
|
|
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)
|
|
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 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.
|
|
"""
|
|
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
|
|
|
|
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 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)
|
|
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):
|
|
# Internal FK's - i.e., those with a related name ending with '+' -
|
|
# don't get a related descriptor.
|
|
if not self.rel.is_hidden():
|
|
setattr(cls, related.get_accessor_name(), ForeignRelatedObjectsDescriptor(related))
|
|
if self.rel.field_name is None:
|
|
self.rel.field_name = cls._meta.pk.name
|
|
|
|
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))
|
|
|
|
def formfield(self, **kwargs):
|
|
if self.rel.parent_link:
|
|
return None
|
|
return super(OneToOneField, self).formfield(**kwargs)
|
|
|
|
def create_many_to_many_intermediary_model(field, klass):
|
|
from django.db import models
|
|
managed = True
|
|
if isinstance(field.rel.to, basestring) and field.rel.to != RECURSIVE_RELATIONSHIP_CONSTANT:
|
|
to = field.rel.to
|
|
to_model = field.rel.to
|
|
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, basestring):
|
|
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 field.rel.to == klass._meta.object_name:
|
|
from_ = 'from_%s' % to.lower()
|
|
to = 'to_%s' % to.lower()
|
|
else:
|
|
from_ = klass._meta.object_name.lower()
|
|
to = to.lower()
|
|
meta = type('Meta', (object,), {
|
|
'db_table': field._get_m2m_db_table(klass._meta),
|
|
'managed': managed,
|
|
'auto_created': klass,
|
|
'unique_together': (from_, to)
|
|
})
|
|
# If the models have been split into subpackages, klass.__module__
|
|
# will be the subpackge, not the models module for the app. (See #12168)
|
|
# Compose the actual models module name by stripping the trailing parts
|
|
# of the namespace until we find .models
|
|
parts = klass.__module__.split('.')
|
|
while parts[-1] != 'models':
|
|
parts.pop()
|
|
module = '.'.join(parts)
|
|
# Construct and return the new class.
|
|
return type(name, (models.Model,), {
|
|
'Meta': meta,
|
|
'__module__': module,
|
|
from_: models.ForeignKey(klass, related_name='%s+' % name),
|
|
to: models.ForeignKey(to_model, related_name='%s+' % name)
|
|
})
|
|
|
|
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:
|
|
assert self.db_table is None, "Cannot specify a db_table if an intermediary model is used."
|
|
|
|
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._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 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 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 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" 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.
|
|
if not self.rel.through and not cls._meta.abstract:
|
|
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, basestring):
|
|
def resolve_through_model(field, model, cls):
|
|
field.rel.through = model
|
|
add_lazy_relation(cls, self, self.rel.through, resolve_through_model)
|
|
|
|
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):
|
|
# Internal M2Ms (i.e., those with a related name ending with '+')
|
|
# don't get a related descriptor.
|
|
if not self.rel.is_hidden():
|
|
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')
|
|
|
|
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:
|
|
initial = defaults['initial']
|
|
if callable(initial):
|
|
initial = initial()
|
|
defaults['initial'] = [i._get_pk_val() for i in 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
|