动态地将属性添加到可翻译的Django模型

时间:2013-08-28 07:15:35

标签: python django properties model

所以我想为一个类似于另一个模型属性的模型添加属性,这个属性包含可翻译的字段。

我的模特:

class MyModel(models.Model):
    ... fields ...

class MyModelTranslation(models.Model):
    ... the fields I want on MyModel ...
    name = models.CharField()
    city = models.CharField()
    language = models.CharField()
    mymodel = models.ForeignKey(MyModel)

所以我写了以下__init__

class MyModel(models.Model):

    ...

    def __init__(self, *args, **kwargs):
        super(Model, self).__init__(*args, **kwargs)
        # get_translation gets the object, that holds the translation fields for the
        # current active language
        trans = lambda c: c.get_translation()

        setattr(self.__class__, 'translation', property(trans))

        fget = lambda c: getattr(trans(c), 'name')
        fset = lambda c, v: setattr(trans(c), 'name', v)
        setattr(self.__class__, 'name', property(fget, fset))

        fget = lambda c: getattr(trans(c), 'city')
        fset = lambda c, v: setattr(trans(c), 'city', v)
        setattr(self.__class__, 'city', property(fget, fset))

这完美无缺。当我打电话给mymodel.name时,我会获得活跃语言的mymodeltranslation.name。也可以设置此值。

因为我希望动态制作它,所以我可以在mixin中使用它,我将它添加到for循环中,如下所示:

   def __init__(self, *args, **kwargs):
        super(Model, self).__init__(*args, **kwargs)
        trans = lambda c: c.get_translation()
        setattr(self.__class__, 'translation', property(trans))

        # returns all fields of the translation model
        trans_fields = [field.name for field in [
            related for related in self._meta.get_all_related_objects()
            if "translation" in related.name
        ][0].model._meta.fields]

        # should then assign all those fields dynamically
        for name in trans_fields:
            if not name == 'id' and not name == 'mymodel':
                fget = lambda c: getattr(trans(c), name)
                fset = lambda c, v: setattr(trans(c), name, v)
                setattr(self.__class__, name, property(fget, fset))

所以我想,好吧,因为name值类似于我之前手动添加的字段名称,它应该添加property,其值为{每次运行for循环时都会{1}}。 但事实并非如此。当我调用name时,它返回模型实例(基本上是mymodel.name)。我不知道什么是不同的,当我在forloop中而不是全部手动执行时。

有什么想法吗?

0 个答案:

没有答案