def __init__(self, to, from_fields, to_fields, swappable=True, **kwargs):
self.from_fields = from_fields
self.to_fields = to_fields
self.swappable = swappable
if 'rel' not in kwargs:
kwargs['rel'] = ForeignObjectRel(
self, to,
related_name=kwargs.pop('related_name', None),
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
parent_link=kwargs.pop('parent_link', False),
on_delete=kwargs.pop('on_delete', CASCADE),
)
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
super(ForeignObject, self).__init__(**kwargs)
python类CASCADE的实例源码
def __init__(self, to, on_delete=None, to_field=None, **kwargs):
kwargs['unique'] = True
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
to_field = on_delete
on_delete = CASCADE # Avoid warning in superclass
super(OneToOneField, self).__init__(to, on_delete, to_field=to_field, **kwargs)
def __init__(self, to, on_delete=None, to_field=None, **kwargs):
kwargs['unique'] = True
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
to_field = on_delete
on_delete = CASCADE # Avoid warning in superclass
super(OneToOneField, self).__init__(to, on_delete, to_field=to_field, **kwargs)
def __init__(self, to, on_delete=None, to_field=None, **kwargs):
kwargs['unique'] = True
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
to_field = on_delete
on_delete = CASCADE # Avoid warning in superclass
super(OneToOneField, self).__init__(to, on_delete, to_field=to_field, **kwargs)
def __init__(self, to, on_delete=None, to_field=None, **kwargs):
kwargs['unique'] = True
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
to_field = on_delete
on_delete = CASCADE # Avoid warning in superclass
super(OneToOneField, self).__init__(to, on_delete, to_field=to_field, **kwargs)
def __init__(self, to, on_delete=None, to_field=None, **kwargs):
kwargs['unique'] = True
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
to_field = on_delete
on_delete = CASCADE # Avoid warning in superclass
super(OneToOneField, self).__init__(to, on_delete, to_field=to_field, **kwargs)
def __init__(self, to, on_delete=None, to_field=None, **kwargs):
kwargs['unique'] = True
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
to_field = on_delete
on_delete = CASCADE # Avoid warning in superclass
super(OneToOneField, self).__init__(to, on_delete, to_field=to_field, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super(ForeignObject, self).deconstruct()
kwargs['from_fields'] = self.from_fields
kwargs['to_fields'] = self.to_fields
if self.rel.related_name is not None:
kwargs['related_name'] = self.rel.related_name
if self.rel.related_query_name is not None:
kwargs['related_query_name'] = self.rel.related_query_name
if self.rel.on_delete != CASCADE:
kwargs['on_delete'] = self.rel.on_delete
if self.rel.parent_link:
kwargs['parent_link'] = self.rel.parent_link
# Work out string form of "to"
if isinstance(self.rel.to, six.string_types):
kwargs['to'] = self.rel.to
else:
kwargs['to'] = "%s.%s" % (self.rel.to._meta.app_label, self.rel.to._meta.object_name)
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error
if hasattr(kwargs['to'], "setting_name"):
if kwargs['to'].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ForeignKey pointing to a model "
"that is swapped in place of more than one model (%s and %s)"
% (kwargs['to'].setting_name, swappable_setting)
)
# Set it
from django.db.migrations.writer import SettingsReference
kwargs['to'] = SettingsReference(
kwargs['to'],
swappable_setting,
)
return name, path, args, kwargs
def __init__(self, to, to_field=None, rel_class=ManyToOneRel,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if 'db_index' not in kwargs:
kwargs['db_index'] = True
self.db_constraint = db_constraint
kwargs['rel'] = rel_class(
self, to, to_field,
related_name=kwargs.pop('related_name', None),
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
parent_link=kwargs.pop('parent_link', False),
on_delete=kwargs.pop('on_delete', CASCADE),
)
super(ForeignKey, self).__init__(to, ['self'], [to_field], **kwargs)
def __init__(self, to, on_delete=None, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
on_delete, to_field = to_field, on_delete
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs['db_index'] = kwargs.get('db_index', True)
super(ForeignKey, self).__init__(
to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type(str('Meta'), (object,), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': '%(from)s-%(to)s relationship' % {'from': from_, 'to': to},
'verbose_name_plural': '%(from)s-%(to)s relationships' % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(str(name), (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
def __init__(self, to, on_delete=None, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
on_delete, to_field = to_field, on_delete
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs['db_index'] = kwargs.get('db_index', True)
super(ForeignKey, self).__init__(
to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type(str('Meta'), (object,), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': _('%(from)s-%(to)s relationship') % {'from': from_, 'to': to},
'verbose_name_plural': _('%(from)s-%(to)s relationships') % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(str(name), (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
def __init__(self, to, on_delete=None, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
on_delete, to_field = to_field, on_delete
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs['db_index'] = kwargs.get('db_index', True)
super(ForeignKey, self).__init__(
to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type(str('Meta'), (object,), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': _('%(from)s-%(to)s relationship') % {'from': from_, 'to': to},
'verbose_name_plural': _('%(from)s-%(to)s relationships') % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(str(name), (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
def __init__(self, to, on_delete=None, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
on_delete, to_field = to_field, on_delete
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs['db_index'] = kwargs.get('db_index', True)
super(ForeignKey, self).__init__(
to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type(str('Meta'), (object,), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': '%(from)s-%(to)s relationship' % {'from': from_, 'to': to},
'verbose_name_plural': '%(from)s-%(to)s relationships' % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(str(name), (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
def __init__(self, to, on_delete=None, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
on_delete, to_field = to_field, on_delete
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs['db_index'] = kwargs.get('db_index', True)
super(ForeignKey, self).__init__(
to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type(str('Meta'), (object,), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': '%(from)s-%(to)s relationship' % {'from': from_, 'to': to},
'verbose_name_plural': '%(from)s-%(to)s relationships' % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(str(name), (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
def __init__(self, to, on_delete=None, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, six.string_types), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if on_delete is None:
warnings.warn(
"on_delete will be a required arg for %s in Django 2.0. Set "
"it to models.CASCADE on models and in existing migrations "
"if you want to maintain the current default behavior. "
"See https://docs.djangoproject.com/en/%s/ref/models/fields/"
"#django.db.models.ForeignKey.on_delete" % (
self.__class__.__name__,
get_docs_version(),
),
RemovedInDjango20Warning, 2)
on_delete = CASCADE
elif not callable(on_delete):
warnings.warn(
"The signature for {0} will change in Django 2.0. "
"Pass to_field='{1}' as a kwarg instead of as an arg.".format(
self.__class__.__name__,
on_delete,
),
RemovedInDjango20Warning, 2)
on_delete, to_field = to_field, on_delete
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs['db_index'] = kwargs.get('db_index', True)
super(ForeignKey, self).__init__(
to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type(str('Meta'), (object,), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': _('%(from)s-%(to)s relationship') % {'from': from_, 'to': to},
'verbose_name_plural': _('%(from)s-%(to)s relationships') % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(str(name), (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
