def __init__(self, to, **kwargs):
"""
create the ForeignObject, but use the to_fields as a dict which will later used as form_fields and to_fields
"""
to_fields = kwargs["to_fields"]
self.null_if_equal = kwargs.pop("null_if_equal", [])
nullable_fields = kwargs.pop("nullable_fields", {})
if not isinstance(nullable_fields, dict):
nullable_fields = {v: None for v in nullable_fields}
self.nullable_fields = nullable_fields
# a list of tuple : (fieldnaem, value) . if fielname = value, then the field react as if fieldnaem_id = None
self._raw_fields = self.compute_to_fields(to_fields)
# hiro nakamura should have said «very bad guy. you are vilain»
if "on_delete" in kwargs:
kwargs["on_delete"] = self.override_on_delete(kwargs["on_delete"])
kwargs["to_fields"], kwargs["from_fields"] = zip(*(
(k, v.value)
for k, v in self._raw_fields.items()
if v.is_local_field
))
super(CompositeForeignKey, self).__init__(to, **kwargs)
python类ForeignObject()的实例源码
def __init__(self, to, **kwargs):
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
kwargs['rel'] = GenericRel(
self, to,
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
)
# Override content-type/object-id field names on the related class
self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
self.content_type_field_name = kwargs.pop("content_type_field", "content_type")
self.for_concrete_model = kwargs.pop("for_concrete_model", True)
kwargs['blank'] = True
kwargs['editable'] = False
kwargs['serialize'] = False
# This construct is somewhat of an abuse of ForeignObject. This field
# represents a relation from pk to object_id field. But, this relation
# isn't direct, the join is generated reverse along foreign key. So,
# the from_field is object_id field, to_field is pk because of the
# reverse join.
super(GenericRelation, self).__init__(
to, to_fields=[],
from_fields=[self.object_id_field_name], **kwargs)
def __init__(self, to, **kwargs):
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
kwargs['rel'] = GenericRel(
self, to,
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
)
# Override content-type/object-id field names on the related class
self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
self.content_type_field_name = kwargs.pop("content_type_field", "content_type")
self.for_concrete_model = kwargs.pop("for_concrete_model", True)
kwargs['blank'] = True
kwargs['editable'] = False
kwargs['serialize'] = False
# This construct is somewhat of an abuse of ForeignObject. This field
# represents a relation from pk to object_id field. But, this relation
# isn't direct, the join is generated reverse along foreign key. So,
# the from_field is object_id field, to_field is pk because of the
# reverse join.
super(GenericRelation, self).__init__(
to, to_fields=[],
from_fields=[self.object_id_field_name], **kwargs)
def __init__(self, to, **kwargs):
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
kwargs['rel'] = GenericRel(
self, to,
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
)
# Override content-type/object-id field names on the related class
self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
self.content_type_field_name = kwargs.pop("content_type_field", "content_type")
self.for_concrete_model = kwargs.pop("for_concrete_model", True)
kwargs['blank'] = True
kwargs['editable'] = False
kwargs['serialize'] = False
# This construct is somewhat of an abuse of ForeignObject. This field
# represents a relation from pk to object_id field. But, this relation
# isn't direct, the join is generated reverse along foreign key. So,
# the from_field is object_id field, to_field is pk because of the
# reverse join.
super(GenericRelation, self).__init__(
to, to_fields=[],
from_fields=[self.object_id_field_name], **kwargs)
def __init__(self, to, **kwargs):
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
kwargs['rel'] = GenericRel(
self, to, related_name=kwargs.pop('related_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),)
# Override content-type/object-id field names on the related class
self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
self.content_type_field_name = kwargs.pop("content_type_field", "content_type")
self.for_concrete_model = kwargs.pop("for_concrete_model", True)
kwargs['blank'] = True
kwargs['editable'] = False
kwargs['serialize'] = False
# This construct is somewhat of an abuse of ForeignObject. This field
# represents a relation from pk to object_id field. But, this relation
# isn't direct, the join is generated reverse along foreign key. So,
# the from_field is object_id field, to_field is pk because of the
# reverse join.
super(GenericRelation, self).__init__(
to, to_fields=[],
from_fields=[self.object_id_field_name], **kwargs)
def __init__(self, to, **kwargs):
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
kwargs['rel'] = GenericRel(
self, to,
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
)
# Override content-type/object-id field names on the related class
self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
self.content_type_field_name = kwargs.pop("content_type_field", "content_type")
self.for_concrete_model = kwargs.pop("for_concrete_model", True)
kwargs['blank'] = True
kwargs['editable'] = False
kwargs['serialize'] = False
# This construct is somewhat of an abuse of ForeignObject. This field
# represents a relation from pk to object_id field. But, this relation
# isn't direct, the join is generated reverse along foreign key. So,
# the from_field is object_id field, to_field is pk because of the
# reverse join.
super(GenericRelation, self).__init__(
to, to_fields=[],
from_fields=[self.object_id_field_name], **kwargs)
def __init__(self, to, **kwargs):
kwargs['verbose_name'] = kwargs.get('verbose_name', None)
kwargs['rel'] = GenericRel(
self, to,
related_query_name=kwargs.pop('related_query_name', None),
limit_choices_to=kwargs.pop('limit_choices_to', None),
)
# Override content-type/object-id field names on the related class
self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
self.content_type_field_name = kwargs.pop("content_type_field", "content_type")
self.for_concrete_model = kwargs.pop("for_concrete_model", True)
kwargs['blank'] = True
kwargs['editable'] = False
kwargs['serialize'] = False
# This construct is somewhat of an abuse of ForeignObject. This field
# represents a relation from pk to object_id field. But, this relation
# isn't direct, the join is generated reverse along foreign key. So,
# the from_field is object_id field, to_field is pk because of the
# reverse join.
super(GenericRelation, self).__init__(
to, to_fields=[],
from_fields=[self.object_id_field_name], **kwargs)
def contribute_to_class(self, cls, name, virtual_only=False):
super(ForeignObject, self).contribute_to_class(cls, name, virtual_only=virtual_only)
setattr(cls, self.name, CompositeForwardManyToOneDescriptor(self))
def contribute_to_class(self, cls, name, virtual_only=False):
super(related.ForeignObject, self).contribute_to_class(cls, name, virtual_only=virtual_only)
setattr(cls, self.name, TextFormatRelatedObjectDescriptor(self))
