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