Include required antl3 library and check if datastore is available
The datastore is checked for availability before requesting it to
be cleared. This is because gaeftest uses its own method for ensuring
no leakage of data by providing a temporary file as the backend.
Reviewed by: Sverre Rabbelier
from django.db import connection, transaction
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
# 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):
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()
related = RelatedObject(other, cls, self)
if not cls._meta.abstract:
self.contribute_to_related_class(other, 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'):
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']:
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:
raise AttributeError, "%s must be accessed via instance" % self.related.opts.object_name
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._default_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
setattr(value, self.related.field.rel.get_related_field().attname, instance)
# 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:
raise AttributeError, "%s must be accessed via instance" % self.field.name
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))
# 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:
raise AttributeError, "Manager must be accessed via instance"
rel_field = self.related.field
rel_model = self.related.model
# Dynamically create a class that subclasses the related
# model's default manager.
superclass = self.related.model._default_manager.__class__
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:
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 __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 create_many_related_manager(superclass, through=False):
"""Creates a manager that subclasses 'superclass' (which is a Manager)
and adds behavior for many-to-many related objects."""
class ManyRelatedManager(superclass):
def __init__(self, model=None, core_filters=None, instance=None, symmetrical=None,
join_table=None, source_col_name=None, target_col_name=None):
super(ManyRelatedManager, self).__init__()
self.core_filters = core_filters
self.model = model
self.symmetrical = symmetrical
self.instance = instance
self.join_table = join_table
self.source_col_name = source_col_name
self.target_col_name = target_col_name
self.through = through
self._pk_val = self.instance._get_pk_val()
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 through is None:
def add(self, *objs):
self._add_items(self.source_col_name, self.target_col_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_col_name, self.source_col_name, *objs)
add.alters_data = True
def remove(self, *objs):
self._remove_items(self.source_col_name, self.target_col_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_col_name, self.source_col_name, *objs)
remove.alters_data = True
def clear(self):
self._clear_items(self.source_col_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_col_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 through is not None:
raise AttributeError, "Cannot use create() on a ManyToManyField which specifies an intermediary model. Use %s's Manager instead." % through
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_col_name, target_col_name, *objs):
# join_table: name of the m2m link table
# 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 add. Either object instances, or primary keys of object instances.
# If there aren't any objects, there is nothing to do.
if objs:
# Check that all the objects are of the right type
new_ids = set()
for obj in objs:
if isinstance(obj, self.model):
new_ids.add(obj._get_pk_val())
else:
new_ids.add(obj)
# Add the newly created or already existing objects to the join table.
# First find out which items are already added, to avoid adding them twice
cursor = connection.cursor()
cursor.execute("SELECT %s FROM %s WHERE %s = %%s AND %s IN (%s)" % \
(target_col_name, self.join_table, source_col_name,
target_col_name, ",".join(['%s'] * len(new_ids))),
[self._pk_val] + list(new_ids))
existing_ids = set([row[0] for row in cursor.fetchall()])
# Add the ones that aren't there already
for obj_id in (new_ids - existing_ids):
cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
(self.join_table, source_col_name, target_col_name),
[self._pk_val, obj_id])
transaction.commit_unless_managed()
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:
raise AttributeError, "Manager must be accessed via instance"
# 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:
raise AttributeError, "Manager must be accessed via instance"
# 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 '%s_%s' % (opts.db_table, self.name)
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