oc-facho/facho/model/fields/one2many.py
bit4bit 1d6d1e2601 One2Many se puede iterar como lista
FossilOrigin-Name: 1de9daae362feb6693b928c4a58c11423127eb1783fdf509f0ef3083b5563b24
2021-06-26 21:32:24 +00:00

67 lines
2.1 KiB
Python

from .field import Field
# TODO(bit4bit) lograr que isinstance se aplique
# al objeto envuelto
class _RelationProxy():
def __init__(self, obj, inst, attribute):
self.__dict__['_obj'] = obj
self.__dict__['_inst'] = inst
self.__dict__['_attribute'] = attribute
def __getattr__(self, name):
if (name in self.__dict__):
return self.__dict__[name]
return getattr(self.__dict__['_obj'], name)
def __setattr__(self, attr, value):
# TODO(bit4bit) hacemos proxy al sistema de notificacion de cambios
# algo burdo, se usa __dict__ para saltarnos el __getattr__ y generar un fallo por recursion
for fun in self.__dict__['_inst']._on_change_fields[self.__dict__['_attribute']]:
fun(self.__dict__['_inst'], self.__dict__['_attribute'], value)
return setattr(self._obj, attr, value)
class _Relation():
def __init__(self, creator, inst, attribute):
self.creator = creator
self.inst = inst
self.attribute = attribute
self.relations = []
def create(self):
n_relations = len(self.relations)
attribute = '%s_%d' % (self.attribute, n_relations)
relation = self.creator(attribute)
proxy = _RelationProxy(relation, self.inst, self.attribute)
self.relations.append(relation)
return proxy
def __len__(self):
return len(self.relations)
def __iter__(self):
for relation in self.relations:
yield relation
class One2Many(Field):
def __init__(self, model, name=None, namespace=None, default=None):
self.model = model
self.field_name = name
self.namespace = namespace
self.default = default
self.relation = None
def __get__(self, inst, cls):
assert self.name is not None
def creator(attribute):
return self._create_model(inst, name=self.field_name, model=self.model, attribute=attribute)
if self.relation:
return self.relation
else:
self.relation = _Relation(creator, inst, self.name)
return self.relation