def override_model_field(model, name, field):
original_field = model._meta.get_field(name)
if not isinstance(field, original_field.__class__):
raise TypeError('Model {!r} field {!r} is not compatible with {!r}'.format(
model, name, field.__class__.__name__
))
if field.remote_field:
related_name = field.remote_field.related_name
if not related_name:
related_name = original_field.remote_field.get_accessor_name()
related_model = getattr(field.remote_field.model, related_name).rel.model
if related_model._meta.proxy:
raise TypeError('There is already a proxy model {!r} related to {!r} using {!r}'.format(
related_model.__name__,
field.remote_field.model.__name__,
related_name
))
model.add_to_class(name, field)
model._meta.local_fields.remove(field)
if field.remote_field:
field.remote_field.model.add_to_class(
related_name,
ReverseManyToOneDescriptor(field.remote_field)
)
def contribute_to_class(self, cls, name, virtual_only=False):
super(StartsWithRelation,
self).contribute_to_class(cls, name, virtual_only)
setattr(cls, self.name, ReverseManyToOneDescriptor(self))
def contribute_to_class(self, cls, name, private_only=False):
super().contribute_to_class(cls, name, private_only)
setattr(cls, self.name, ReverseManyToOneDescriptor(self))